RESUMO
AIMS: Although intrauterine growth restriction (IUGR) impairs immune system homeostasis and lung development, its relationship with the susceptibility to pulmonary infections remains unclear. Thus, this study aimed to investigate the impact of IUGR on acute lung inflammatory response induced by bacterial stimulus. MATERIALS AND METHODS: Pregnant female Wistar rats were subjected to 50% caloric-protein food restriction during gestation. To mimic bacterial lung infection, adult male offspring (12 weeks old) were challenged with a single lipopolysaccharide (LPS) intranasal instillation, and 6 h later, we assessed the acute inflammatory response. Normal birth weight (NBW) animals represent the control group. KEY FINDINGS: LPS instillation increased the protein levels in the airways of both the NBW and low birth weight (LBW) groups, indicating vascular leakage. LBW animals exhibited a lower number of neutrophils, reduced production of interleukin-6 and macrophage-inflammatory protein-2 and decreased upregulation of intercellular adhesion molecule-1 gene expression in lung tissues. Further analysis revealed that the LBW group produced lower levels of prostaglandin-E2 and failed to secrete leukotriene-B4 upon LPS stimulation, which correlated with impaired cyclooxygenase-2 and 5-lipoxygenase expression. These results were probably associated with their inability to upregulate the expression of Toll-like receptor-4 and downstream signaling proteins, such as nuclear factor kappa-B, in the lungs. The LBW group also exhibited abnormal airway thickening and high corticosterone levels under basal conditions. SIGNIFICANCE: This study suggests that IUGR-induced foetal programming in LBW offspring threatens HPA axis physiology and corticosterone biodisponibility, and impairs the innate response to bacterial antigens, increasing future susceptibility to pulmonary infection.
Assuntos
Corticosterona/biossíntese , Suscetibilidade a Doenças , Retardo do Crescimento Fetal , Pneumonia Bacteriana/imunologia , Efeitos Tardios da Exposição Pré-Natal , Animais , Ácido Araquidônico/metabolismo , Feminino , Sistema Hipotálamo-Hipofisário/metabolismo , Lipopolissacarídeos/administração & dosagem , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Masculino , NF-kappa B/metabolismo , Sistema Hipófise-Suprarrenal/metabolismo , Gravidez , Ratos , Ratos Wistar , Receptor 4 Toll-Like/metabolismoRESUMO
Postmenopausal period has been associated to different symptoms such as hot flashes, vulvovaginal atrophy, hypoactive sexual desire disorder (HSDD) and others. Clinical studies have described postmenopausal women presenting HSDD can benefit from the association of testosterone to conventional hormonal therapy. Testosterone has been linked to development of cardiovascular diseases including hypertension and it also increases cytochrome P-450-induced 20-HETE synthesis which in turn results in vascular dysfunction. However, the effect of testosterone plus estrogen in the cardiovascular system is still very poorly studied. The aim of the present study is to evaluate the role of cytochrome P-450 pathway in a postmenopausal hypertensive female treated with testosterone plus estrogen. For that, hypertensive ovariectomized rats (OVX-SHR) were used as a model of postmenopausal hypertension and four groups were created: SHAM-operated (SHAM), ovariectomized SHR (OVX), OVX treated for 15 days with conjugated equine estrogens [(CEE) 9.6 µg/Kg/day/po] or CEE associated to testosterone [(CEE+T) 2.85 mg/kg/weekly/im]. Phenylephrine-induced contraction and generation of reactive oxygen species (ROS) were markedly increased in aortic rings from OVX-SHR compared to SHAM rats which were restored by CEE treatment. On the other hand, CEE+T abolished vascular effects by CEE and augmented both systolic and diastolic blood pressure of SHR. Treatment of aortic rings with the CYP/20-HETE synthesis inhibitor HET0016 (1 µM) reduced phenylephrine hyperreactivity and the augmented ROS generation in the CEE+T group. These results are paralleled by the increased CYP4F3 protein expression and activity in aortas of CEE+T. In conclusion, we showed that association of testosterone to estrogen therapy produces detrimental effects in cardiovascular system of ovariectomized hypertensive females via CYP4F3/20-HETE pathway. Therefore, our findings support the standpoint that the CYP/20-HETE pathway is an important therapeutic target for the prevention of cardiovascular disease in menopausal women in the presence of high levels of testosterone.
RESUMO
The study aimed to evaluate if maternal exposure to fluoxetine (FLX) during pregnancy and lactation would result in altered aortic reactivity in adult offspring. We also sought to understand the role of endothelium derived relaxing factors in aortic response. Wistar rats (7580 days old), whose progenitors had received FLX (5 mg/kg, FLX offspring) or tap water (control offspring) during pregnancy and lactation were anesthetized, after which the aorta was removed and cut into two rings, one with (Endo+) and the other without (Endo-) endothelium. Concentration-effect curves for acetylcholine (ACh), sodium nitroprusside (SNP), and phenylephrine (Phe) were performed. The vasodilation to ACh and SNP was similar between control and FLX groups in both male and female offspring. In male rats, the response to Phe was similar between the FLX and control groups on Endo+ and Endo- rings. The response to Phe was reduced on Endo+ rings from female FLX when compared with the control group. The endothelium removal, as well as L-NAME, indomethacin, and tranylcypromine incubation corrected the reduced Phe-induced contraction in the aorta from the female FLX group. On the other hand, catalase, NS-398, and L-NIL did not interfere with the vasoconstriction. The aortic level of nitric oxide (NO) was higher in the female FLX than the control group. Although endothelial NO synthase isoform and cyclooxygenase (COX)-1 expressions were similar between the groups, there was a notable increment in neuronal NO synthase expression in the aorta of FLX-exposed female rats, suggesting an important role of this enzyme in the higher levels of NO. Our results show that developmental exposure to FLX causes sex-specific alteration in aortic function through a mechanism involving endothelial factors, probably NO and COX-1 products.
Assuntos
Antidepressivos de Segunda Geração/farmacologia , Aorta Torácica/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Fluoxetina/farmacologia , Lactação , Músculo Liso Vascular/efeitos dos fármacos , Efeitos Tardios da Exposição Pré-Natal , Vasoconstrição/efeitos dos fármacos , Animais , Aorta Torácica/metabolismo , Ciclo-Oxigenase 1/metabolismo , Relação Dose-Resposta a Droga , Endotélio Vascular/metabolismo , Feminino , Idade Gestacional , Masculino , Proteínas de Membrana/metabolismo , Músculo Liso Vascular/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo I/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Gravidez , Ratos Wistar , Fatores Sexuais , Transdução de Sinais/efeitos dos fármacos , Vasoconstritores/farmacologia , Vasodilatadores/farmacologiaRESUMO
The mechanisms whereby testosterone increases cardiovascular risk are not clarified. However, oxidative stress and inflammation seem to be determinants. Herein, we sought to determine whether exogenous testosterone, at physiological levels, induces leucocyte migration, a central feature in immune and inflammatory responses and the mediating mechanisms. We hypothesized that testosterone induces leucocyte migration via NADPH oxidase (NADPHox)-driven reactive oxygen species (ROS) and cyclooxygenase (COX)-dependent mechanisms. Sixteen-week-old Wistar rats received an intraperitoneal injection (5 ml) of either testosterone (10(-7) mol/l) or saline. Rats were pre-treated with 5 ml of sodium salicylate (SS, non-selective COX inhibitor, 1.25 × 10(-3) mol/l, 1 h prior to testosterone or saline), flutamide (androgen receptor antagonist, 10(-5) mol/l), apocynin (NADPHox inhibitor, 3 × 10(-4) mol/l), N-[2-Cyclohexyloxy-4-nitrophenyl]methanesulfonamide (NS398, COX2 inhibitor, 10(-4) mol/l) or saline, 4 h before testosterone or saline administration. Leucocyte migration was assessed 24 h after testosterone administration by intravital microscopy of the mesenteric bed. Serum levels of testosterone were measured by radioimmunoassay. NADPHox activity was assessed in membrane fractions of the mesenteric bed by dihydroethidium (DHE) fluorescence and in isolated vascular smooth muscle cells (VSMC) by HPLC. NADPHox subunits and VCAM (vascular cell adhesion molecule) expression were determined by immunoblotting. Testosterone administration did not change serum levels of endogenous testosterone, but increased venular leucocyte migration to the adventia, NADPHox activity and expression (P < 0.05). These effects were blocked by flutamide. SS inhibited testosterone-induced leucocyte migration (P<0.05). Apocynin and NS398 abolished testosterone-induced leucocyte migration and NADPHox activity (P<0.05). Testosterone induces leucocyte migration via NADPHox- and COX2-dependent mechanisms and may contribute to inflammatory processes and oxidative stress in the vasculature potentially increasing cardiovascular risk.
Assuntos
Movimento Celular/efeitos dos fármacos , Ciclo-Oxigenase 2/metabolismo , Leucócitos/efeitos dos fármacos , NADPH Oxidases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Testosterona/farmacologia , Acetofenonas/farmacologia , Androgênios/farmacologia , Animais , Western Blotting , Células Cultivadas , Inibidores Enzimáticos/farmacologia , Injeções Intraperitoneais , Leucócitos/citologia , Leucócitos/metabolismo , Masculino , Veias Mesentéricas/citologia , Veias Mesentéricas/efeitos dos fármacos , Veias Mesentéricas/metabolismo , Microscopia de Vídeo/métodos , Músculo Liso Vascular/citologia , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/metabolismo , NADPH Oxidases/antagonistas & inibidores , Nitrobenzenos/farmacologia , Ratos Wistar , Transdução de Sinais/efeitos dos fármacos , Sulfonamidas/farmacologia , Superóxidos/metabolismo , Testosterona/administração & dosagemRESUMO
The kallikrein-kinin and renin-angiotensin systems interact at multiple levels. In the present study, we tested the hypothesis that the B1 kinin receptor (B1R) contributes to vascular hypertrophy in angiotensin II (ANG II)-induced hypertension, through a mechanism involving reactive oxygen species (ROS) generation and extracellular signal-regulated kinase (ERK1/2) activation. Male Wistar rats were infused with vehicle (control rats), 400 ng/Kg/min ANG II (ANG II rats) or 400 ng/Kg/min ANG II plus B1 receptor antagonist, 350 ng/Kg/min des-Arg(9)-Leu(8)-bradykinin (ANGII+DAL rats), via osmotic mini-pumps (14 days) or received ANG II plus losartan (10 mg/Kg, 14 days, gavage - ANG II+LOS rats). After 14 days, ANG II rats exhibited increased systolic arterial pressure [(mmHg) 184 ± 5.9 vs 115 ± 2.3], aortic hypertrophy; increased ROS generation [2-hydroxyethidium/dihydroethidium (EOH/DHE): 21.8 ± 2.7 vs 6.0 ± 1.8] and ERK1/2 phosphorylation (% of control: 218.3 ± 29.4 vs 100 ± 0.25]. B1R expression was increased in aortas from ANG II and ANG II+DAL rats than in aortas from the ANG II+LOS and control groups. B1R antagonism reduced aorta hypertrophy, prevented ROS generation (EOH/DHE: 9.17 ± 3.1) and ERK1/2 phosphorylation (137 ± 20.7%) in ANG II rats. Cultured aortic vascular smooth muscle cells (VSMC) stimulated with low concentrations (0.1 nM) of ANG II plus B1R agonist exhibited increased ROS generation, ERK1/2 phosphorylation, proliferating-cell nuclear antigen expression and [H3]leucine incorporation. At this concentration, neither ANG II nor the B1R agonist produced any effects when tested individually. The ANG II/B1R agonist synergism was inhibited by losartan (AT1 blocker, 10 µM), B1R antagonist (10 µM) and Tiron (superoxide anion scavenger, 10 mM). These data suggest that B1R activation contributes to ANG II-induced aortic hypertrophy. This is associated with activation of redox-regulated ERK1/2 pathway that controls aortic smooth muscle cells growth. Our findings highlight an important cross-talk between the DABK and ANG II in the vascular system and contribute to a better understanding of the mechanisms involved in vascular remodeling in hypertension.
Assuntos
Hipertensão/patologia , Sistema Calicreína-Cinina/fisiologia , Sistema Renina-Angiotensina/fisiologia , Angiotensina II/toxicidade , Animais , Anti-Hipertensivos/farmacologia , Anti-Hipertensivos/uso terapêutico , Aorta/metabolismo , Aorta/patologia , Pressão Sanguínea/efeitos dos fármacos , Antagonistas de Receptor B1 da Bradicinina/farmacologia , Células Cultivadas , Sinergismo Farmacológico , Hipertensão/tratamento farmacológico , Hipertensão/metabolismo , Hipertrofia/metabolismo , Sistema Calicreína-Cinina/efeitos dos fármacos , Losartan/farmacologia , Losartan/uso terapêutico , Masculino , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/metabolismo , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Receptor B1 da Bradicinina/agonistas , Receptor B1 da Bradicinina/metabolismo , Sistema Renina-Angiotensina/efeitos dos fármacos , Superóxidos/metabolismoRESUMO
Intrauterine growth restriction (IUGR) is associated with impaired vascular function, which contributes to the increased incidence of chronic disease. The aim of this study was to investigate whether aerobic training improves AngII-induced vasoconstriction in IUGR rats. Moreover, we assess the role of superoxide dismutase (SOD) isoforms and NADPH oxidase-derived superoxide anions in this improvement. Female Wistar rats were randomly divided into two groups on day 1 of pregnancy. A control group was fed standard chow ad libitum, and a restricted group was fed 50% of the ad libitum intake throughout gestation. At 8 weeks of age, male offspring from both groups were randomly assigned to 4 experimental groups: sedentary control (SC), trained control (TC), sedentary restricted (SRT), and trained restricted (TRT). The training protocol was performed on a treadmill and consisted of a continuous 60-min session 5 days/week for 10 weeks. Following aerobic training, concentration-response curves to AngII were obtained in endothelium-intact aortic rings. Protein expression of SOD isoforms, AngII receptors and the NADPH oxidase component p47phox was assessed by Western blot analysis. The dihydroethidium was used to evaluate the in situ superoxide levels under basal conditions or in the presence of apocynin, losartan or PD 123,319. Our results indicate that aerobic training can prevent IUGR-associated increases in AngII-dependent vasoconstriction and can restore basal superoxide levels in the aortic rings of TRT rats. Moreover, we observed that aerobic training normalized the increased p47phox protein expression and increased MnSOD and AT2 receptor protein expression in thoracic aortas of SRT rats. In summary, aerobic training can result in an upregulation of antioxidant defense by improved of MnSOD expression and attenuation of NADPH oxidase component p47phox. These effects are accompanied by increased expression of AT2 receptor, which provide positive effects against Ang II-induced superoxide generation, resulting in attenuation of AngII-induced vasoconstriction.
Assuntos
Angiotensina II/metabolismo , Retardo do Crescimento Fetal/fisiopatologia , Regulação da Expressão Gênica/fisiologia , Estresse Oxidativo/fisiologia , Condicionamento Físico Animal/fisiologia , Receptor Tipo 2 de Angiotensina/metabolismo , Animais , Feminino , Masculino , NADPH Oxidases/metabolismo , Gravidez , Ratos , Superóxido Dismutase/metabolismo , Vasoconstrição/fisiologiaRESUMO
It has been clearly established that mitogen-activated protein kinases (MAPKS) are important mediators of angiotensin II (Ang II) signaling via AT1 receptors in the vasculature. However, evidence for a role of these kinases in changes of Ang II-induced vasoconstriction in obesity is still lacking. Here we sought to determine whether vascular MAPKs are differentially activated by Ang II in obese animals. The role of AT2 receptors was also evaluated. Male monosodium glutamate-induced obese (obese) and non-obese Wistar rats (control) were used. The circulating concentrations of Ang I and Ang II, determined by HPLC, were increased in obese rats. Ang II-induced isometric contraction was decreased in endothelium-intact resistance mesenteric arteries from obese compared with control rats and exhibited a retarded AT1 receptor antagonist response. Blocking of AT2 receptors and inhibition of either endothelial nitric oxide synthase (eNOS) or extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) restored Ang II-induced contraction in obese rats. Western blot analysis revealed increased protein expression of AT2 receptors in arteries from obese rats. Basal and Ang II-induced ERK1/2 phosphorylation was also increased in obese rats. Blockade of either AT1 or AT2 receptors corrected the increased ERK1/2 phosphorylation in arteries from obese rats to levels observed in control preparations. Phosphorylation of eNOS was increased in obese rats. Incubation with the ERK1/2 inhibitor before Ang II stimulation did not affect eNOS phosphorylation in control rats; however, it corrected the increased phosphorylation of eNOS in obese rats. These results clearly demonstrate that enhanced AT2 receptor and ERK1/2-induced, NO-mediated vasodilation reduces Ang II-induced contraction in an endothelium-dependent manner in obese rats.
Assuntos
Artérias Mesentéricas/fisiologia , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Obesidade/fisiopatologia , Receptor Tipo 2 de Angiotensina/metabolismo , Angiotensina II/farmacologia , Bloqueadores do Receptor Tipo 2 de Angiotensina II/farmacologia , Animais , Western Blotting , Endotélio Vascular/fisiologia , Inibidores Enzimáticos/farmacologia , Imidazóis/farmacologia , Técnicas In Vitro , Masculino , Artérias Mesentéricas/metabolismo , Proteína Quinase 1 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 3 Ativada por Mitógeno/antagonistas & inibidores , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo III/antagonistas & inibidores , Obesidade/metabolismo , Fosforilação/efeitos dos fármacos , Piridinas/farmacologia , Ratos Wistar , Regulação para Cima , Vasoconstrição/efeitos dos fármacos , Vasoconstritores/farmacologiaRESUMO
BACKGROUND/AIMS: We investigated the effects of leptin in the development of lipopolysaccharide (LPS)-induced acute lung inflammation (ALI) in lean mice. METHODS: Mice were administered leptin (1.0µg/g) or leptin (1.0µg/g) followed by LPS (1.5µg/g) intranasally. Additionally, some animals were given LPS (1.5µg/g) or saline intranasally alone, as a control. Tissue samples and fluids were collected six hours after instillation. RESULTS: We demonstrated that leptin alone did not induce any injury. Local LPS exposure resulted in significant acute lung inflammation, characterized by a substantial increase in total cells, mainly neutrophils, in bronchoalveolar lavages (BAL). We also observed a significant lymphocyte influx into the lungs associated with enhanced lung expression of chemokines and cytokines (KC, RANTES, TNF-α, IFN-γ, GM-CSF and VEGF). LPS-induced ALI was characterized by the enhanced expression of ICAM-1 and iNOS in the lungs. Mice that received LPS showed an increase in insulin levels. Leptin, when administered prior to LPS instillation, abolished all of these effects. LPS induced an increase in corticosterone levels, and leptin potentiated this event. CONCLUSION: These data suggest that exogenous leptin may promote protection during sepsis, and downregulation of the insulin levels and upregulation of corticosterone may be important mechanisms in the amelioration of LPS-induced ALI.
Assuntos
Lesão Pulmonar Aguda , Corticosterona/farmacologia , Insulina/farmacologia , Leptina/farmacologia , Lipopolissacarídeos/toxicidade , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/tratamento farmacológico , Lesão Pulmonar Aguda/metabolismo , Lesão Pulmonar Aguda/patologia , Animais , Citocinas/biossíntese , Molécula 1 de Adesão Intercelular/biossíntese , Masculino , Camundongos , Óxido Nítrico Sintase Tipo II/biossínteseRESUMO
Impaired vascular function, manifested by an altered ability of the endothelium to release endothelium-derived relaxing factors and endothelium-derived contracting factors, is consistently reported in obesity. Considering that the endothelium plays a major role in the relaxant response to the cannabinoid agonist anandamide, the present study tested the hypothesis that vascular relaxation to anandamide is decreased in obese rats. Mechanisms contributing to decreased anandamide-induced vasodilation were determined. Resistance mesenteric arteries from young obese Zucker rats (OZRs) and their lean counterparts (LZRs) were used. Vascular reactivity was evaluated in a myograph for isometric tension recording. Protein expression and localization were analyzed by Western blotting and immunofluorescence, respectively. Vasorelaxation to anandamide, acetylcholine, and sodium nitroprusside, as well as to CB1, CB2, and TRPV1 agonists was decreased in endothelium-intact mesenteric arteries from OZRs. Incubation with an AMP-dependent protein kinase (AMPK) activator or a fatty acid amide hydrolase inhibitor restored anandamide-induced vascular relaxation in OZRs. CB1 and CB2 receptors protein expression was decreased in arteries from OZRs. Incubation of mesenteric arteries with anandamide evoked endothelial nitric oxide synthase (eNOS), AMPK and acetyl CoA carboxylase phosphorylation in LZRs, whereas it decreased phosphorylation of these proteins in OZRs. In conclusion, obesity decreases anandamide-induced relaxation in resistance arteries. Decreased cannabinoid receptors expression, increased anandamide degradation, decreased AMPK/eNOS activity as well as impairment of the response mediated by TRPV1 activation seem to contribute to reduce responses to cannabinoid agonists in obesity.
Assuntos
Ácidos Araquidônicos/farmacologia , Endocanabinoides/farmacologia , Endotélio Vascular/fisiopatologia , Artérias Mesentéricas/fisiopatologia , Obesidade/fisiopatologia , Alcamidas Poli-Insaturadas/farmacologia , Vasodilatação/efeitos dos fármacos , Acetil-CoA Carboxilase/metabolismo , Adenilato Quinase/metabolismo , Animais , Agonistas de Receptores de Canabinoides/farmacologia , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/enzimologia , Técnicas In Vitro , Masculino , Artérias Mesentéricas/efeitos dos fármacos , Artérias Mesentéricas/enzimologia , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Obesidade/metabolismo , Fosforilação/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Ratos , Ratos Zucker , Receptor CB1 de Canabinoide/metabolismo , Receptor CB2 de Canabinoide/metabolismo , Canais de Cátion TRPV/metabolismoRESUMO
OBJECTIVE: The increased risk of cardiovascular diseases in postmenopausal women has been linked to the decrease in plasma estrogen levels. Preparation of conjugate equine estrogens (CEE) is one of the most routinely used hormone therapy in postmenopausal women. However, studies on the vascular effects of CEE are still sparse and the mechanism of action is not completely elucidated. In this context, we have determined the effects of CEE in the vascular oxidative stress observed in ovariectomyzed (OVX) spontaneously hypertensive rats (SHR). Mechanisms by which CEE interferes with redox-sensitive pathways and endothelial function were also determined. RESULTS: Aortas from OVX rats exhibited increased generation of reactive oxygen species (ROS), NADPH oxidase activity and reduced catalase protein expression, compared to aortas from sham SHR. Endothelium-intact aortic rings from OVX were hyperreactive to NE when compared to Sham aortas. This hyperreactivity was corrected by superoxide dismutase (SOD), catalase, and endothelium removal. Treatment of OVX-SHR with CEE reduced vascular ROS generation, NADPH oxidase activity, enhanced SOD and catalase expression and also corrected the NE-hyperreactivity in aortic rings from OVX-SHR. CONCLUSION: Our study indicates a potential benefit of CEE therapy through a mechanism that involves reduction in oxidative stress, improving endothelial function in OVX hypertensive rats.
Assuntos
Aorta/efeitos dos fármacos , Estrogênios Conjugados (USP)/farmacologia , Hipertensão/tratamento farmacológico , Ovariectomia , Espécies Reativas de Oxigênio/antagonistas & inibidores , Animais , Aorta/metabolismo , Catalase/metabolismo , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Feminino , Expressão Gênica/efeitos dos fármacos , Cavalos , Humanos , Hipertensão/metabolismo , NADPH Oxidases/antagonistas & inibidores , NADPH Oxidases/metabolismo , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/biossíntese , Óxido Nítrico Sintase Tipo III/antagonistas & inibidores , Óxido Nítrico Sintase Tipo III/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Endogâmicos SHR , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo , Técnicas de Cultura de TecidosRESUMO
BACKGROUND: Diabetes differentially affects the vascular system in males and females. Although various results have been reported, very few studies have focused on responses in females. In the present study, we investigated contractile responses to norepinephrine in aortas of alloxan-diabetic female rats and evaluated endothelial modulation of these responses. METHODS: Concentration-response curves were constructed to norepinephrine in the absence or presence of N(G) -nitro-l-arginine methyl ester (l-NAME), indomethacin, losartan, tezosentan, and calphostin C; pre-pro-endothelin mRNA expression was evaluated; and norepinephrine-stimulated expression of phosphorylated (p-) Akt Ser(473) , p-endothelial nitric oxide synthase (eNOS) Ser(1177) , and p-eNOS Ser(633) was determined in endothelial cells incubated in the presence of low (5 mmol/L) or high (25 mmol/L) glucose concentrations. RESULTS: Similar maximal responses (Rmax ) to norepinephrine were seen in control and diabetic endothelium-intact aortas; however, Rmax was reduced in diabetic endothelium-denuded aortas. Incubation of endothelium-intact aortas with 100 µmol/L l-NAME increased Rmax in the control group only. Inhibition of cyclo-oxygenase (10 µmol/L indomethacin) and blockade of angiotensin II receptors (10 µmol/L losartan) reduced Rmax in endothelium-intact aortas in both the control and diabetic groups. Blockade of endothelin receptors (0.1 µmol/L tezosentan) and inhibition of protein kinase C (PKC; 0.1 µmol/L calphostin C) reduced Rmax only in endothelium-intact aortas from diabetic rats. Pre-pro-endothelin mRNA expression was increased in aortas from diabetic female rats. Finally, p-Akt Ser(473) , p-eNOS Ser(1177) , and p-eNOS Ser(633) levels were enhanced after norepinephrine stimulation only in low glucose-treated endothelial cells. CONCLUSIONS: In aortas of diabetic female rats, reductions in smooth muscle contractile responses to norepinephrine are counterbalanced by the endothelium via reduced eNOS activation and increased endothelin release and PKC activation.
Assuntos
Aorta Torácica/fisiopatologia , Diabetes Mellitus Experimental/fisiopatologia , Endotelinas/metabolismo , Endotélio Vascular/metabolismo , Músculo Liso Vascular/fisiopatologia , Óxido Nítrico/metabolismo , Animais , Aorta Torácica/metabolismo , Diabetes Mellitus Experimental/metabolismo , Feminino , Músculo Liso Vascular/metabolismo , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , VasoconstriçãoRESUMO
Endothelial dysfunction has been implicated in portal vein obstruction, a condition responsible for major complications in chronic portal hypertension. Increased vascular tone due to disruption of endothelial function has been associated with an imbalance in the equilibrium between endothelium-derived relaxing and contracting factors. Herein, we assessed underlying mechanisms by which expression of bradykinin B(1) receptor (B(1)R) is induced in the endothelium and how its stimulation triggers vasoconstriction in the rat portal vein. Prolonged in vitro incubation of portal vein resulted in time- and endothelium-dependent expression of B(1)R and cyclooxygenase-2 (COX-2). Inhibition of protein kinase C (PKC) or phosphatidylinositol 3-kinase (PI3K) significantly reduced expression of B(1)R through the regulation of transcription factors, activator protein-1 (AP-1) and cAMP response element-binding protein (CREB). Moreover, pharmacological studies showed that B(1)R-mediated portal vein contraction was reduced by COX-2, but not COX-1, inhibitors. Notably, activation of endothelial B(1)R increased phospholipase A(2)/COX-2-derived thromboxane A(2) (TXA(2)) levels, which in turn mediated portal vein contraction through binding to TXA(2) receptors expressed in vascular smooth muscle cells. These results provide novel molecular mechanisms involved in the regulation of B(1)R expression and identify a critical role for the endothelial B(1)R in the modulation of portal vein vascular tone. Our study suggests a potential role for B(1)R antagonists as therapeutic tools for diseases where portal hypertension may be involved.
Assuntos
Bradicinina/farmacologia , Endotélio/metabolismo , Veia Porta/efeitos dos fármacos , Receptor B1 da Bradicinina/metabolismo , Vasoconstrição/efeitos dos fármacos , Animais , Bradicinina/análogos & derivados , Relação Dose-Resposta a Droga , Masculino , Veia Porta/metabolismo , Ratos , Ratos Wistar , Receptor B1 da Bradicinina/biossíntese , Relação Estrutura-AtividadeRESUMO
Testosterone has been implicated in vascular remodeling associated with hypertension. Molecular mechanisms underlying this are elusive, but oxidative stress may be important. We hypothesized that testosterone stimulates generation of reactive oxygen species (ROS) and migration of vascular smooth muscle cells (VSMCs), with enhanced effects in cells from spontaneously hypertensive rats (SHRs). The mechanisms (genomic and nongenomic) whereby testosterone induces ROS generation and the role of c-Src, a regulator of redox-sensitive migration, were determined. VSMCs from male Wistar-Kyoto rats and SHRs were stimulated with testosterone (10(-7) mol/L, 0-120 minutes). Testosterone increased ROS generation, assessed by dihydroethidium fluorescence and lucigenin-enhanced chemiluminescence (30 minutes [SHR] and 60 minutes [both strains]). Flutamide (androgen receptor antagonist) and actinomycin D (gene transcription inhibitor) diminished ROS production (60 minutes). Testosterone increased Nox1 and Nox4 mRNA levels and p47phox protein expression, determined by real-time PCR and immunoblotting, respectively. Flutamide, actinomycin D, and cycloheximide (protein synthesis inhibitor) diminished testosterone effects on p47phox. c-Src phosphorylation was observed at 30 minutes (SHR) and 120 minutes (Wistar-Kyoto rat). Testosterone-induced ROS generation was repressed by 3-(4-chlorophenyl) 1-(1,1-dimethylethyl)-1H-pyrazolo[3,4-day]pyrimidin-4-amine (c-Src inhibitor) in SHRs and reduced by apocynin (antioxidant/NADPH oxidase inhibitor) in both strains. Testosterone stimulated VSMCs migration, assessed by the wound healing technique, with greater effects in SHRs. Flutamide, apocynin, and 3-(4-chlorophenyl) 1-(1,1-dimethylethyl)-1H-pyrazolo[3,4-day]pyrimidin-4-amine blocked testosterone-induced VSMCs migration in both strains. Our study demonstrates that testosterone induces VSMCs migration via NADPH oxidase-derived ROS and c-Src-dependent pathways by genomic and nongenomic mechanisms, which are differentially regulated in VSMCs from Wistar-Kyoto rats and SHRs.
Assuntos
Movimento Celular/efeitos dos fármacos , Músculo Liso Vascular/efeitos dos fármacos , NADPH Oxidases/metabolismo , Proteínas Proto-Oncogênicas pp60(c-src)/metabolismo , Transdução de Sinais/efeitos dos fármacos , Testosterona/farmacologia , Antagonistas de Androgênios/farmacologia , Androgênios/farmacologia , Animais , Células Cultivadas , Cicloeximida/farmacologia , Dactinomicina/farmacologia , Flutamida/farmacologia , Immunoblotting , Masculino , Músculo Liso Vascular/citologia , Músculo Liso Vascular/metabolismo , NADH NADPH Oxirredutases/genética , NADH NADPH Oxirredutases/metabolismo , NADPH Oxidase 1 , NADPH Oxidase 4 , NADPH Oxidases/genética , Inibidores da Síntese de Proteínas/farmacologia , Proteínas Proto-Oncogênicas pp60(c-src)/antagonistas & inibidores , Pirimidinas/farmacologia , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Activation of TLRs (Toll-like receptors) induces gene expression of proteins involved in the immune system response. TLR4 has been implicated in the development and progression of CVDs (cardio-vascular diseases). Innate and adaptive immunity contribute to hypertension-associated end-organ damage, although the mechanism by which this occurs remains unclear. In the present study, we hypothesize that inhibition of TLR4 decreases BP (blood pressure) and improves vascular contractility in resistance arteries from SHR (spontaneously hypertensive rats). TLR4 protein expression in mesenteric resistance arteries was higher in 15-week-old SHR than in age-matched Wistar controls or in 5-week-old SHR. To decrease the activation of TLR4, 15-week-old SHR and Wistar rats were treated with anti-TLR4 (anti-TLR4 antibody) or non-specific IgG control antibody for 15 days (1 µg per day, intraperitoneal). Treatment with anti-TLR4 decreased MAP (mean arterial pressure) as well as TLR4 protein expression in mesenteric resistance arteries and IL-6 (interleukin 6) serum levels from SHR when compared with SHR treated with IgG. No changes in these parameters were found in treated Wistar control rats. Mesenteric resistance arteries from anti-TLR4-treated SHR exhibited decreased maximal contractile response to NA (noradrenaline) compared with IgG-treated SHR. Inhibition of COX (cyclo-oxygenase)-1 and COX-2, enzymes related to inflammatory pathways, decreased NA responses only in mesenteric resistance arteries of SHR treated with IgG. COX-2 expression and TXA2 (thromboxane A2) release were decreased in SHR treated with anti-TLR4 compared with IgG-treated SHR. Our results suggest that TLR4 activation contributes to increased BP, low-grade inflammation and plays a role in the augmented vascular contractility displayed by SHR.
Assuntos
Pressão Sanguínea , Hipertensão/fisiopatologia , Receptor 4 Toll-Like/fisiologia , Vasoconstrição , Animais , Artérias/fisiopatologia , Ciclo-Oxigenase 1/sangue , Ciclo-Oxigenase 2/sangue , Epoprostenol/sangue , Regulação da Expressão Gênica , Hemodinâmica/efeitos dos fármacos , Hipertensão/genética , Imunidade Inata , Interleucina-6/sangue , Masculino , Proteínas de Membrana/sangue , Artérias Mesentéricas/metabolismo , Ratos , Ratos Endogâmicos SHR , Ratos Wistar , Tromboxano A2/sangue , Receptor 4 Toll-Like/antagonistas & inibidores , Receptor 4 Toll-Like/imunologia , Fator de Necrose Tumoral alfa/sangueRESUMO
Nutritional deficiency is commonly associated with a significantly impaired immune response, particularly in relation to cell-mediated immunity, the complement system, cytokine production and phagocyte function. However, there are few data on the consequences of nutritional deficiency in allergic diseases of the lung. In fact, malnutrition is the most common cause of immunodeficiency worldwide. Several studies have indicated that the incidence of alterations in lung functions can be associated with birth weight, specifically with maternal malnutrition, but data linking intrauterine undernutrition with allergic diseases of the lung are lacking. The purpose of this review is to associate malnutrition, including intrauterine malnutrition, with the establishment of immune responses and the development of lung allergic inflammation.
Assuntos
Asma/imunologia , Asma/fisiopatologia , Transtornos da Nutrição Fetal/imunologia , Transtornos da Nutrição Fetal/fisiopatologia , Sistema Imunitário/fisiopatologia , Animais , Autoanticorpos/imunologia , Proteínas do Sistema Complemento/imunologia , Citocinas/imunologia , Feminino , Humanos , Sistema Imunitário/embriologia , Sistema Imunitário/crescimento & desenvolvimento , Imunidade Celular/imunologia , Recém-Nascido de Baixo Peso/imunologia , Recém-Nascido , Fagócitos/imunologia , GravidezRESUMO
In addition to reducing blood pressure, hydralazine can reduce the production of inflammatory cytokines and reduce the expression of leukocyte adhesion molecules. Differences in leukocyte behavior and leukocyte adhesion molecule expression in spontaneously hypertensive rats (SHR) compared to normotensive rats have been reported. However, whether hydralazine can reduce leukocyte migration in vivo in hypertension and in normotension remains unknown. To address this question, male SHR and Wistar rats were treated for 15 days with hydralazine at a dose of ~3.5 mg/kg or ~14 mg/kg in their drinking water. The numbers of rollers and adherent and migrated cells were determined by direct vital microscopy, and blood pressure was assessed by tail plethysmography. In addition, following treatment with the higher dose, immunohistochemistry was used to measure the expression of intercellular adhesion molecule-1 (ICAM-1), P-selectin, and platelet-endothelial cell adhesion molecule-1 (PECAM-1) in endothelial cells, while flow cytometry was used to evaluate the expression of leukocyte CD18 and L-selectin. Hydralazine reduced leukocyte adherence and migration in SHR either at the higher, that reduced blood pressure levels, or lower dose, which did not reduce it. Reduced ICAM-1 expression might be involved in the reduced migration observed in SHR. In Wistar rats, only at the higher dose hydralazine reduced blood pressure levels and leukocyte migration. Reduced P-selectin expression might be involved. We therefore conclude that hydralazine reduces leukocyte migration by different mechanisms in SHR and Wistar rats, specifically by reducing ICAM-1 expression in the former and P-selectin expression in the latter.
Assuntos
Anti-Inflamatórios/farmacologia , Anti-Hipertensivos/farmacologia , Moléculas de Adesão Celular/metabolismo , Quimiotaxia de Leucócito/efeitos dos fármacos , Hidralazina/farmacologia , Hipertensão/tratamento farmacológico , Leucócitos/efeitos dos fármacos , Animais , Velocidade do Fluxo Sanguíneo/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Antígenos CD18/metabolismo , Adesão Celular/efeitos dos fármacos , Moléculas de Adesão Celular/genética , Modelos Animais de Doenças , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/imunologia , Citometria de Fluxo , Hipertensão/imunologia , Hipertensão/fisiopatologia , Imuno-Histoquímica , Molécula 1 de Adesão Intercelular/metabolismo , Selectina L/metabolismo , Contagem de Leucócitos , Migração e Rolagem de Leucócitos/efeitos dos fármacos , Leucócitos/imunologia , Masculino , Microscopia de Vídeo , Selectina-P/metabolismo , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Pletismografia , RNA Mensageiro/metabolismo , Ratos , Ratos Endogâmicos SHR , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
The ETs (endothelins) comprise a family of three 21-amino-acid peptides (ET-1, ET-2 and ET-3) and 31-amino-acid ETs (ET-1(1-31), ET-2(1-31) and ET-3(1-31)). ET-1 is synthesized from a biologically inactive precursor, big ET-1, by ECEs (ET-converting enzymes). The actions of ET-1 are mediated through activation of the G-protein-coupled ET(A) and ET(B) receptors, which are found in a variety of cells in the cardiovascular and renal systems. ET-1 has potent vasoconstrictor, mitogenic, pro-inflammatory and antinatriuretic properties, which have been implicated in the pathophysiology of a number of cardiovascular diseases. Overexpression of ET-1 has been consistently described in salt-sensitive models of hypertension and in models of renal failure, and has been associated with disease progression. Sex differences are observed in many aspects of mammalian cardiovascular function and pathology. Hypertension, as well as other cardiovascular diseases, is more common in men than in women of similar age. In experimental models of hypertension, males develop an earlier and more severe form of hypertension than do females. Although the reasons for these differences are not well established, the effects of gonadal hormones on arterial, neural and renal mechanisms that control blood pressure are considered contributing factors. Sex differences in the ET-1 pathway, with males displaying higher ET-1 levels, greater ET-1-mediated vasoconstrictor and enhanced pressor responses in comparison with females, are addressed in the present review. Sex-associated differences in the number and function of ET(B) receptors appear to be particularly important in the specific characteristics of hypertension between females and males. Although the gonadal hormones modulate some of the differences in the ET pathway in the cardiovascular system, a better understanding of the exact mechanisms involved in sex-related differences in this peptidergic system is needed. With further insights into these differences, we may learn that men and women could require different antihypertensive regimens.
Assuntos
Endotelinas/fisiologia , Hipertensão/fisiopatologia , Caracteres Sexuais , Anti-Hipertensivos/uso terapêutico , Fenômenos Fisiológicos Cardiovasculares , Antagonistas dos Receptores de Endotelina , Feminino , Humanos , Hipertensão/tratamento farmacológico , Rim/fisiologia , Masculino , Receptores de Endotelina/fisiologia , Transdução de Sinais/fisiologiaRESUMO
OBJECTIVE: To evaluate the safety of a combined diphtheria-tetanus-whole cell pertussis-Haemophilus influenzae type b vaccine used on the Brazilian National Immunizations Program, chiefly the incidence of hypotonic-hyporesponsive episodes. METHOD: Follow-up of a cohort of 21,064 infants (20,925 or 99.7% adhered to the study protocol), within 48 hours of vaccination with diphtheria-tetanus-whole cell pertussis-Haemophilus influenzae type b vaccine in health care units in the City of Rio de Janeiro, to ascertain and investigate spontaneous and solicited severe adverse events. Each child was followed-up for one dose only. RESULTS: The rate of hypotonic-hyporesponsive episodes was 1/1,744 doses (confirmed cases) and 1/1,495 doses (confirmed plus suspect cases). The rate of convulsions was 1/5,231 doses. No cases of apnea were detected. These results are comparable to those found in the literature with diphtheria-tetanus-whole cell pertussis vaccine. CONCLUSION: The diphtheria-tetanus-whole cell pertussis-Haemophilus influenzae type b vaccine under study can be safely used in the National Immunizations Program, according to the current precautions and contraindications.
Assuntos
Vacina contra Difteria, Tétano e Coqueluche/efeitos adversos , Febre/etiologia , Vacinas Anti-Haemophilus/efeitos adversos , Programas de Imunização/estatística & dados numéricos , Convulsões/etiologia , Brasil/epidemiologia , Estudos de Coortes , Difteria/prevenção & controle , Vacina contra Difteria, Tétano e Coqueluche/administração & dosagem , Feminino , Febre/epidemiologia , Infecções por Haemophilus/prevenção & controle , Vacinas Anti-Haemophilus/administração & dosagem , Humanos , Incidência , Lactente , Entrevistas como Assunto , Masculino , Convulsões/epidemiologia , Índice de Gravidade de Doença , Tétano/prevenção & controle , Coqueluche/prevenção & controleRESUMO
OBJETIVO: Avaliar a segurança da vacina combinada de difteria-tétano-coqueluche de células inteiras e Haemophilus influenzae tipo b usada no Programa Nacional de Imunizações, e em especial a incidência de episódios hipotônicos-hiporresponsivos. MÉTODO: Acompanhamento de uma coorte de 21.064 lactentes (20.925 ou 99,7 por cento aderiram ao protocolo de estudo), nas 48 horas após a aplicação da vacina de difteria, tétano, coqueluche de células inteiras e Haemophilus influenzae tipo b em centros de saúde na cidade do Rio de Janeiro, para determinar e investigar eventos adversos graves, espontâneos e solicitados. Cada criança foi monitorada durante somente uma dose. RESULTADOS: A incidência de episódios hipotônicos-hiporresponsivos foi de 1:1.744 doses (casos confirmados) e de 1:1.495 doses (casos confirmados mais casos suspeitos). A taxa de incidência de convulsões foi de 1:5.231 doses. Não foram detectados casos de apnéia. Esses resultados são comparáveis àqueles relatados na literatura para a vacina contra difteria-tétano-coqueluche de células inteiras. CONCLUSÃO: A vacina contra difteria, tétano, coqueluche de células inteiras e Haemophilus influenzae tipo b em estudo pode ser usada com segurança no Programa Nacional de Imunizações, de acordo com as precauções e contra-indicações correntes.
OBJECTIVE:To evaluate the safety of a combined diphtheria-tetanus-whole cell pertussis-Haemophilus influenzae type b vaccine used on the Brazilian National Immunizations Program, chiefly the incidence of hypotonic-hyporesponsive episodes. METHOD: Follow-up of a cohort of 21,064 infants (20,925 or 99.7 percent adhered to the study protocol), within 48 hours of vaccination with diphtheria-tetanus-whole cell pertussis-Haemophilus influenzae type b vaccine in health care units in the City of Rio de Janeiro, to ascertain and investigate spontaneous and solicited severe adverse events. Each child was followed-up for one dose only. RESULTS: The rate of hypotonic-hyporesponsive episodes was 1/1,744 doses (confirmed cases) and 1/1,495 doses (confirmed plus suspect cases). The rate of convulsions was 1/5,231 doses. No cases of apnea were detected. These results are comparable to those found in the literature with diphtheria-tetanus-whole cell pertussis vaccine. CONCLUSION: The diphtheria-tetanus-whole cell pertussis-Haemophilus influenzae type b vaccine under study can be safely used in the National Immunizations Program, according to the current precautions and contraindications.
Assuntos
Feminino , Humanos , Lactente , Masculino , Vacina contra Difteria, Tétano e Coqueluche/efeitos adversos , Febre/etiologia , Vacinas Anti-Haemophilus/efeitos adversos , Programas de Imunização/estatística & dados numéricos , Convulsões/etiologia , Brasil/epidemiologia , Estudos de Coortes , Vacina contra Difteria, Tétano e Coqueluche/administração & dosagem , Difteria/prevenção & controle , Febre/epidemiologia , Infecções por Haemophilus/prevenção & controle , Vacinas Anti-Haemophilus/administração & dosagem , Incidência , Entrevistas como Assunto , Índice de Gravidade de Doença , Convulsões/epidemiologia , Tétano/prevenção & controle , Coqueluche/prevenção & controleRESUMO
We investigated whether angiotensin II infusion modulates in vivo the kinin B1 receptor expression and the mechanisms involved in this process. We also evaluated the role of the B1 receptor activation in aorta. Wistar rats received 400 ng/kg per minute of angiotensin II or saline (control rats) infusion during 14 days through an osmotic minipump. To investigate the role of superoxide anion in B1 receptor expression, rats received a reduced nicotinamide-adenine dinucleotide phosphate oxidase inhibitor in the drinking water during 14 days (60 mg/L of apocynin) simultaneously with angiotensin II infusion. Angiotensin II induced B1 receptor expression in the aorta and increased significantly systolic blood pressure, superoxide anion, and the nuclear factor kappaB activity. Apocynin treatment did not alter the blood pressure levels of angiotensin II rats and reduced the B1 receptor expression, superoxide anion generation, and nuclear factor kappaB activity to similar levels of the control rats. Vascular reactivity studies in isolated aorta reveal that B1 receptor agonist promoted endothelium-dependent dilation and increased the NO generation in aorta of angiotensin II rats. NO synthase inhibitor and B1 receptor antagonist inhibited the vasodilation and NO generation, which were not affected by B2 receptor antagonist or indomethacin. These results provide evidence that angiotensin II induces B1 receptor expression in aorta by superoxide anion generation, via reduced nicotinamide-adenine dinucleotide phosphate oxidase, concomitant to nuclear factor kappaB activation. We have also shown that B1 receptor agonist causes endothelium-dependent vasodilation through NO production in aortic rings, suggesting that the B1 receptor expression could be related with the vascular tonus control of angiotensin II rats.