RESUMO
Here, we tested the hypothesis that TNAP (tissue nonspecific alkaline phosphatase) modulates vascular responsiveness to norepinephrine. In the isolated, Tyrode's-perfused rat mesentery, 50 µmol/L of L-p-bromotetramisole (L-p-BT; selective TNAP inhibitor, Ki=56 µmol/L) significantly reduced TNAP activity and caused a significant 9.0-fold rightward-shift in the norepinephrine concentration versus vasoconstriction relationship. At 100 µmol/L, L-p-BT further reduced mesenteric TNAP activity and caused an additional significant right-shift of the norepinephrine concentration versus vasoconstriction relationship. A higher concentration (200 µmol/L) of L-p-BT had no further effect on either mesenteric TNAP activity or norepinephrine-induced vasoconstriction. L-p-BT did not alter vascular responses to vasopressin, thus ruling-out nonspecific suppression of vascular reactivity. Since in the rat mesenteric vasculature α1-adrenoceptors mediate norepinephrine-induced vasoconstriction, these finding indicate that TNAP inhibition selectively interferes with α1-adrenoceptor signaling. Additional experiments showed that the effects of TNAP inhibition on norepinephrine-induced vasoconstriction were not mediated by accumulation of pyrophosphate or ATP (TNAP substrates) nor by reduced adenosine levels (TNAP product). TNAP inhibition significantly reduced the Hillslope of the norepinephrine concentration versus vasoconstriction relationship from 1.8±0.2 (consistent with positive cooperativity of α1-adrenoceptor signaling) to 1.0±0.1 (no cooperativity). Selective activation of A1-adenosine receptors, which are known to participate in coincident signaling with α1-adrenoceptors, reversed the suppressive effects of L-p-BT on norepinephrine-induced vasoconstriction. In vivo, L-p-BT administration achieved plasma levels of ≈60 µmol/L and inhibited mesenteric vascular responses to exogenous norepinephrine and sympathetic nerve stimulation. TNAP modulates vascular responses to norepinephrine likely by affecting positive cooperativity of α1-adrenoceptor signaling via a mechanism involving A1 receptor signaling.
Assuntos
Fosfatase Alcalina/metabolismo , Proteínas de Membrana/metabolismo , Mesentério/efeitos dos fármacos , Norepinefrina/farmacologia , Tetramizol/análogos & derivados , Vasoconstrição/efeitos dos fármacos , Vasoconstritores/farmacologia , Antagonistas do Receptor A1 de Adenosina/farmacologia , Fosfatase Alcalina/antagonistas & inibidores , Fosfatase Alcalina/genética , Animais , Masculino , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/genética , Mesentério/metabolismo , Ratos , Tetramizol/farmacologia , Xantinas/farmacologiaRESUMO
Endothelial cells participate in extracellular ATP release elicited by mechanosensors. To characterize the dynamic interactions between mechanical and chemical factors that modulate ATP secretion by the endothelium, we assessed and compared the mechanisms participating in the spontaneous (basal) and mechanically stimulated secretion using primary cultures of rat mesentery endothelial cells. ATP/metabolites were determined in the cell media prior to (basal) and after cell media displacement or a picospritzer buffer puff used as mechanical stimuli. Mechanical stimulation increased extracellular ATP that peaked within 1 min, and decayed to basal values in 10 min. Interruption of the vesicular transport route consistently blocked the spontaneous ATP secretion. Cells maintained in media lacking external Ca2+ elicited a spontaneous rise of extracellular ATP and adenosine, but failed to elicit a further extracellular ATP secretion following mechanical stimulation. 2-APB, a TRPV agonist, increased the spontaneous ATP secretion, but reduced the mechanical stimulation-induced nucleotide release. Pannexin1 or connexin blockers and gadolinium, a Piezo1 blocker, reduced the mechanically induced ATP release without altering spontaneous nucleotide levels. Moreover, thrombin or related agonists increased extracellular ATP secretion elicited by mechanical stimulation, without modifying spontaneous release. In sum, present results allow inferring that the spontaneous, extracellular nucleotide secretion is essentially mediated by ATP containing vesicles, while the mechanically induced secretion occurs essentially by connexin or pannexin1 hemichannel ATP transport, a finding fully supported by results from Panx1-/- rodents. Only the latter component is modulated by thrombin and related receptor agonists, highlighting a novel endothelium-smooth muscle signaling role of this anticoagulant.
Assuntos
Trifosfato de Adenosina/metabolismo , Células Endoteliais/metabolismo , Mecanotransdução Celular/fisiologia , Canais de Cátion TRPV/metabolismo , Trombina/metabolismo , Animais , Células Cultivadas , Masculino , Mesentério/citologia , Mesentério/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ratos , Ratos Sprague-DawleyRESUMO
Deep RNA sequencing (RNA-seq) provides a practical and inexpensive alternative for exploring genomic data in non-model organisms. The functional annotation of non-model mammalian genomes, such as that of goats, is still poor compared to that of humans and mice. In the current study, we performed a whole transcriptome analysis of an intestinal mucous membrane lymph node to comprehensively characterize the transcript catalogue of this tissue in a goat. Using an Illumina HiSeq 4000 sequencing platform, 9.692 GB of raw reads were acquired. A total of 57,526 lymph transcripts were obtained, and the majority of these were mapped to known transcriptional units (42.67%). A comparison of the mRNA expression of the mesenteric lymph nodes during the juvenile and post-adolescent stages revealed 8949 transcripts that were differentially expressed, including 6174 known genes. In addition, we functionally classified these transcripts using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) terms. A total of 6174 known genes were assigned to 64 GO terms, and 3782 genes were assigned to 303 KEGG pathways, including some related to immunity. Our results reveal the complex transcriptome profile of the lymph node and suggest that the immune system is immature in the mesenteric lymph nodes of juvenile goats.
Assuntos
Cabras/genética , Linfonodos/metabolismo , Transcriptoma , Animais , Regulação da Expressão Gênica no Desenvolvimento , Mesentério/metabolismo , Anotação de Sequência MolecularRESUMO
Galectin-3 is a ß-galactoside-binding protein with an inhibitory role in B cell differentiation into plasma cells in distinct lymphoid tissues. We use a model of chronic schistosomiasis, a well-characterized experimental disease hallmarked by polyclonal B cell activation, in order to investigate the role of galectin-3 in controlling IgA production through peritoneal B1 cells. Chronically infected, galectin-3-deficient mice (Lgals3(-/-)) display peritoneal fluid hypercellularity, increased numbers of atypical peritoneal IgM(+)/IgA(+) B1a and B1b lymphocytes and histological disturbances in plasma cell niches when compared with Lgals3(+/+) mice. Similar to our infection model, peritoneal B1 cells from uninfected Lgals3(-/-) mice show enhanced switching to IgA after in vitro treatment with interleukin-5 plus transforming growth factor-ß (IL-5 + TGF-ß1). A higher number of IgA(+) B1a lymphocytes was found in the peritoneal cavity of Lgals3(-/-)-uninfected mice at 1 week after i.p. injection of IL-5 + TGF-ß1; this correlates with the increased levels of secreted IgA detected in the peritoneal fluid of these mice after cytokine treatment. Interestingly, a higher number of degranulated mast cells is present in the peritoneal cavity of uninfected and Schistosoma mansoni-infected Lgals3(-/-) mice, indicating that, at least in part, mast cells account for the enhanced differentiation of B1 into IgA-producing B cells found in the absence of galectin-3. Thus, a novel role is revealed for galectin-3 in controlling the expression of surface IgA by peritoneal B1 lymphocytes; this might have important implications for manipulating the mucosal immune response.
Assuntos
Linfócitos B/citologia , Linfócitos B/metabolismo , Diferenciação Celular , Galectina 3/deficiência , Imunoglobulina A/metabolismo , Peritônio/citologia , Regulação para Cima , Animais , Contagem de Células , Degranulação Celular , Proliferação de Células , Forma Celular , Doença Crônica , Galectina 3/metabolismo , Imunoglobulina A/sangue , Switching de Imunoglobulina , Imunoglobulina M/sangue , Interleucina-5 , Mastócitos/fisiologia , Mesentério/metabolismo , Camundongos Endogâmicos C57BL , Omento/metabolismo , Fenótipo , Plasmócitos/metabolismo , Esquistossomose/sangue , Esquistossomose/imunologia , Esquistossomose/parasitologia , Esquistossomose/patologia , Fator de Crescimento Transformador beta1/metabolismoRESUMO
OBJECTIVE: To evaluate the mesenteric tissue oxygenation response in preterm infants fed and not fed during red blood cell (RBC) transfusions. STUDY DESIGN: Prospective, observational comparison of mesenteric oxygenation using near-infrared spectroscopy in preterm infants (<33 weeks' at birth) who were fed or not fed during RBC transfusion. Tissue oxygenation means were examined up to 48 hours after each transfusion event. RESULTS: Mean mesenteric regional oxygen saturation (rSO2) slopes during RBC transfusion of fed (n = 9) vs not fed (n = 8) infants ranged from -0.23 to +0.23 (mean 0.04) with no differences between groups (P = .480). However, following transfusions, postprandial mesenteric oxygenation means significantly declined in infants fed during transfusion compared with infants not fed during transfusion (P < .001). Infants fed during RBC transfusion had a mean 2.16 point decrease in rSO2 mesenteric oxygenation with each sequential feeding post-transfusion, whereas infants not fed during RBC transfusion increased their rSO2 postprandial mesenteric oxygenation by a mean of 2.09 points. CONCLUSIONS: Mesenteric tissue oxygenation during RBC transfusion is not influenced by feeding status. However, infants fed during RBC transfusion had, for the next 15 hours, decreasing postprandial mesenteric tissue oxygenation patterns compared with infants not fed during RBC transfusion. Feeding during RBC transfusions may increase the risk for mesenteric ischemia and the development of transfusion-related necrotizing enterocolitis in preterm infants.
Assuntos
Nutrição Enteral , Transfusão de Eritrócitos , Mesentério/metabolismo , Oxigênio/metabolismo , Período Pós-Prandial , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Estudos ProspectivosRESUMO
The colocalization, number, and size of various classes of enteric neurons immunoreactive (IR) for the purinergic P2X2 and P2X7 receptors (P2X2R, P2X7R) were analyzed in the myenteric and submucosal plexuses of control, undernourished, and re-fed rats. Pregnant rats were exposed to undernourishment (protein-deprivation) or fed a control diet, and their offspring comprised the following experimental groups: rats exposed to a normal diet throughout gestation until postnatal day (P)42, rats protein-deprived throughout gestation and until P42, and rats protein-deprived throughout gestation until P21 and then given a normal diet until P42. Immunohistochemistry was performed on the myenteric and submucosal plexuses to evaluate immunoreactivity for P2X2R, P2X7R, nitric oxide synthase (NOS), choline acetyltransferase (ChAT), calbindin, and calretinin. Double-immunohistochemistry of the myenteric and submucosal plexuses demonstrated that 100% of NOS-IR, calbindin-IR, calretinin-IR, and ChAT-IR neurons in all groups also expressed P2X2R and P2X7R. Neuronal density increased in the myenteric and submucosal plexuses of undernourished rats compared with controls. The average size (profile area) of some types of neurons in the myenteric and submucosal plexuses was smaller in the undernourished than in the control animals. These changes appeared to be reversible, as animals initially undernourished but then fed a normal diet at P21 (re-feeding) were similar to controls. Thus, P2X2R and P2X7R are present in NOS-positive inhibitory neurons, calbindin- and calretinin-positive intrinsic primary afferent neurons, cholinergic secretomotor neurons, and vasomotor neurons in rats. Alterations in these neurons during undernourishment are reversible following re-feeding.
Assuntos
Mesentério , Neurônios/metabolismo , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Deficiência de Proteína/metabolismo , Animais , Calbindina 2/metabolismo , Calbindinas/metabolismo , Colina O-Acetiltransferase/metabolismo , Feminino , Masculino , Mesentério/crescimento & desenvolvimento , Mesentério/inervação , Mesentério/metabolismo , Mesentério/patologia , Proteínas do Tecido Nervoso/metabolismo , Neurônios/patologia , Óxido Nítrico Sintase/metabolismo , Gravidez , Efeitos Tardios da Exposição Pré-Natal/patologia , Deficiência de Proteína/patologia , Ratos , Ratos Wistar , Receptores Purinérgicos P2X2/metabolismo , Receptores Purinérgicos P2X7/metabolismoRESUMO
Crohn's disease (CD) is characterized by inflammation and an aetiology that is still unknown. Hypertrophy of mesenteric fat is a reflection of disease activity, as this fat covers the entire length of the affected area. Adipocytes synthesize leptin and adiponectin, adipocytokines responsible for pro- and anti-inflammatory effects. Therefore, we evaluated serum levels of adiponectin and leptin, as well as mesenteral expression of adiponectin in active CD and those in remission. Sixteen patients with ileocaecal CD followed at the Outpatient Clinic, Coloproctology Unit of University of Campinas Clinical Hospital, participated in the study. Analysis of serum adiponectin and leptin by enzyme-linked immunosorbent assay was performed in patients with active CD (ACD group), remission CD (RCD group) and in six healthy controls. Ten patients with active ileocaecal CD (FCD group) and eight patients with non-inflammatory disease selected for surgery were also studied. The specimens were snap-frozen and the expression of adiponectin was determined by immunoblot of protein extracts. Serum C-reactive protein levels were higher in the ACD group when compared to the others and no difference of body mass index was observed between the groups. Serum adiponectin was lower in the ACD group when compared to control, but no differences were seen when comparing the ACD and RCD groups. Mesenteric adiponectin expression was lower in the FCD group when compared to the FC group. Serum leptin was similar in all groups. The lower levels of serum and mesenteric adiponectin in active CD suggest a defective regulation of anti-inflammatory pathways in CD pathogenesis.
Assuntos
Adiponectina/metabolismo , Tecido Adiposo/metabolismo , Doença de Crohn/metabolismo , Leptina/metabolismo , Mesentério/metabolismo , Adiponectina/sangue , Adolescente , Adulto , Antígenos CD/metabolismo , Índice de Massa Corporal , Proteína C-Reativa/metabolismo , Doença de Crohn/sangue , Feminino , Humanos , Leptina/sangue , Masculino , Mesentério/patologia , Pessoa de Meia-Idade , Adulto JovemRESUMO
Purinergic signaling has been established as an important feature of inflammation and homeostasis. The expression of a number of P2 receptor subtypes in the gut has been reported. In this study, using a well-known permeabilization method that is assessed by flow cytometry, we show that lymphocytes and macrophages from the mesenteric lymph nodes (MLN) and the peritoneal cavity exhibit different sensitivities to extracellular ATP. Compared with the macrophages, the lymphocytes are more sensitive to ATP in the MLN compartment, whereas in the peritoneal cavity the macrophages are more sensitive to ATP than the lymphocytes. In addition, we have shown that the epithelial cells from the small bowel are more resistant to the ATP effects than the cells from the colon. These cells, however, become susceptible after exposure to IFN-γ. Furthermore, by examining parameters such as pH manipulation, the exposure to divalent cations and the P2X7 antagonist Brilliant Blue G, and the use of cells from P2X7(-/-) mice, we have shown that the P2X7 receptors are the ATP-activated receptors responsible for the permeabilization phenomenon. In addition, using Western blot analysis, we have demonstrated the changes in the P2X7 receptor expression in immune cells isolated from different sites in the gut and in the gut-associated lymphoid tissues. Our findings suggest the existence of the site-specific modulation of P2X7 receptors on epithelial and immune cells, and we define purinergic signaling as a new regulatory element in the control of inflammation and cell fate in the gut and in the gut-associated lymphoid tissues.
Assuntos
Trifosfato de Adenosina/farmacologia , Células Epiteliais/metabolismo , Trato Gastrointestinal/metabolismo , Linfócitos/metabolismo , Macrófagos/metabolismo , Receptores Purinérgicos P2X7/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Colo/citologia , Colo/metabolismo , Células Epiteliais/efeitos dos fármacos , Feminino , Trato Gastrointestinal/citologia , Intestino Delgado/citologia , Intestino Delgado/metabolismo , Linfonodos/citologia , Linfonodos/imunologia , Linfonodos/metabolismo , Linfócitos/efeitos dos fármacos , Linfócitos/imunologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Masculino , Mesentério/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Peritônio/citologia , Peritônio/imunologia , Peritônio/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
Oestradiol (E(2)) is a key hormone in the regulation of reproductive processes. The aims of this work were a) to examine the distributions of oestrogen receptor α (ERα) and ERß in the neurons of the superior mesenteric ganglion (SMG) in the oestrus stage by immunohistochemistry, b) to demonstrate whether E(2) in the SMG modifies progesterone (P(4)), androstenedione (A(2)) and nitrite release in the ovarian compartment on oestrus day and c) to demonstrate whether E(2) in the ganglion modifies the activity and gene expression in the ovary of the steroidogenic enzymes 3ß-hydroxysteroid dehydrogenase (3ß-HSD) and 20α-hydroxysteroid dehydrogenase (20α-HSD). The ex vivo SMG-ovarian nervous plexus-ovary system was used. E(2), tamoxifen (Txf) and E(2) plus Txf were added in the ganglion to measure ovarian P(4) release, while E(2) alone was added to measure ovarian A(2) and nitrites release. Immunohistochemistry revealed cytoplasmic ERα immunoreactivity only in the neural somas in the SMG. E(2) increased ovarian P(4) and A(2) release at 15, 30 and 60âmin but decreased nitrites. The activity and gene expression of 3ß-HSD increased, while the activity and gene expression of 20α-HSD did not show changes with respect to the control. Txf in the ganglion diminished P(4) release only at 60âmin. E(2) plus Txf in the ganglion reverted the effect of E(2) alone and the inhibitory effect of Txf. The results of this study demonstrate that ERα activation in the SMG has an impact on ovarian steroidogenesis in rats, thus providing evidence for the critical role of peripheral system neurons in the control of ovarian functions under normal and pathological conditions.
Assuntos
Gânglios Simpáticos/metabolismo , Ovário/metabolismo , Receptores de Estrogênio/fisiologia , Esteroides/biossíntese , 20-Hidroxiesteroide Desidrogenases/genética , 20-Hidroxiesteroide Desidrogenases/metabolismo , 3-Hidroxiesteroide Desidrogenases/genética , 3-Hidroxiesteroide Desidrogenases/metabolismo , Animais , Estradiol/farmacologia , Estro/efeitos dos fármacos , Estro/genética , Estro/metabolismo , Estro/fisiologia , Feminino , Gânglios Simpáticos/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Hormônios Esteroides Gonadais/biossíntese , Mesentério/inervação , Mesentério/metabolismo , Ovário/efeitos dos fármacos , Ovário/inervação , Progesterona/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores de Estrogênio/agonistas , Receptores de Estrogênio/metabolismo , Tamoxifeno/farmacologiaRESUMO
High doses of diazepam reduce the inflammatory paw edema in rats. This effect was attributed to an action of diazepam on the Translocator Protein (TSPO). We evaluated the effects of diazepam (10 mg/kg, intraperitoneally) on leukocyte rolling and migration. In carrageenan-induced acute inflammation, diazepam decreased the interaction of leukocytes with endothelial cells (rolling) and the number of leukocytes in the mesentery (migration). RU486 (antagonist of glucocorticoid receptors) reduced the effects of diazepam on leukocyte rolling and migration, suggesting a participation of endogenous corticosteroids. We also showed that the effects of diazepam on leukocyte-endothelium interactions are mediated by nitric oxide (NO), since prior treatment with l-arginine (precursor of NO) partially precludes the inhibitory effects of diazepam; conversely, pretreatment with L-NAME (false substrate of the NO synthase) somewhat potentiates the effects of diazepam. The pathways that underlie the effects of diazepam remain to be further elucidated, but we believe that both local and systemic mechanisms may overlap to explain the influence of diazepam on leukocyte-endothelium interactions.
Assuntos
Diazepam/farmacologia , Endotélio Vascular/efeitos dos fármacos , Inflamação/imunologia , Migração e Rolagem de Leucócitos/efeitos dos fármacos , Leucócitos/efeitos dos fármacos , Psicotrópicos/farmacologia , Animais , Arginina/metabolismo , Carragenina/farmacologia , Masculino , Mesentério/efeitos dos fármacos , Mesentério/metabolismo , Mifepristona/farmacologia , NG-Nitroarginina Metil Éster/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/metabolismo , Ratos , Ratos WistarRESUMO
The effect of exogenous Gal-1 on cellular response and adhesion molecule expression was investigated in a classical model of acute inflammation induced by zymosan. C57BL6 mice, treated or not with human recombinant (hr) Gal-1, received i.p. injection of zymosan and peritoneal exudate, blood and mesentery were processed for cellular, biochemical, light and electron microscopic analysis after 4 and 24 h. Zymosan peritonitis provoked the expected signs of inflammation at 4 h, including a significant increase in extravasated PMNs in the mesentery and peritoneal exudate, mirrored by blood neutrophilia. These changes subsided after 24 h. Ultrastructural immunocytochemical analysis of PMNs showed significant Gal-1 expression and co-localization with L-selectin and ß2-integrin in the plasma membrane and cytoplasm. Pharmacological treatment with hrGal-1 at 4 h produced an inhibition of PMN migration, associated with diminished expression of adhesion molecules, particularly ß2-integrin, and TNF-α and IL-1ß release by peritoneal cells. At 24 h, Gal-1 induced an increase in mononuclear phagocytic cell recruitment. In conclusion, our data propose an important mechanism of anti-inflammatory action of Gal-1, initially by modulation of pro-inflammatory cytokine release and PMN migration through an imbalance between adhesion molecule expression and, later, by promoting monocyte-macrophage recruitment.
Assuntos
Moléculas de Adesão Celular/metabolismo , Citocinas/metabolismo , Galectina 1/farmacologia , Leucócitos/efeitos dos fármacos , Animais , Antígenos CD18/metabolismo , Ensaios de Migração de Leucócitos , Movimento Celular/efeitos dos fármacos , Modelos Animais de Doenças , Exsudatos e Transudatos/química , Exsudatos e Transudatos/metabolismo , Galectina 1/metabolismo , Humanos , Molécula 1 de Adesão Intercelular , Selectina L/metabolismo , Leucócitos/metabolismo , Leucócitos/patologia , Masculino , Mesentério/efeitos dos fármacos , Mesentério/metabolismo , Mesentério/patologia , Camundongos , Camundongos Endogâmicos C57BL , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Monócitos/patologia , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Neutrófilos/patologia , Peritonite/imunologia , Peritonite/metabolismo , Peritonite/patologia , Proteínas RecombinantesRESUMO
Current knowledge suggests that adipose tissue is an active organ, participating in intestinal and mesenteric disease. Additionally, adipose tissue surrounds the lymph nodes and has special properties, acting as a paracrine regulator of adjacent lymphoid tissues. These adipose tissue depots can express and secrete numerous cytokines, known as adipocytokines, which then modify the action of insulin in adipose tissue itself. Using a well-accepted model of intestinal inflammation, we studied insulin signaling in mesenteric adipose tissue (MAT) and in perinodal mesenteric adipose tissue (PAT). Our results showed that the action of insulin is modified during the intestinal inflammatory response in these adipose tissue depots. MAT became resistant to insulin signaling, as evaluated by the IRS/AKT pathway, in the inflammation. This resistant status was associated with high JNK activity and the presence of infiltrating macrophages. Conversely, the adipose tissue that involves the mesenteric lymph nodes acquired greater sensitivity to insulin signaling via IRS/AKT, probably via up-regulation of IRS during experimental colitis. We demonstrated experimentally the existence of site-specific adaptive alterations in two mesenteric adipose tissue depots to the intestinal inflammatory response, probably resulting in alterations in free fatty acids and other secretory products supplied by the adjacent tissues that could act as inflammatory modulator substances.
Assuntos
Tecido Adiposo/metabolismo , Colite/metabolismo , Proteínas Substratos do Receptor de Insulina/metabolismo , Mucosa Intestinal/metabolismo , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/imunologia , Animais , Colite/induzido quimicamente , Colite/imunologia , Insulina/farmacologia , Proteínas Substratos do Receptor de Insulina/efeitos dos fármacos , Intestinos/imunologia , Masculino , Mesentério/imunologia , Mesentério/metabolismo , Peroxidase/metabolismo , Fosforilação/efeitos dos fármacos , Fosforilação/fisiologia , Ratos , Ratos Wistar , Transdução de Sinais/fisiologia , Ácido Trinitrobenzenossulfônico/farmacologia , Tirosina/efeitos dos fármacos , Tirosina/metabolismoRESUMO
1 A fructose-enriched diet induces hypertension, metabolic alterations and insulin resistance in rats, resembling human metabolic syndrome. Previously, we found that prostanoid production was altered in fructose-fed rats. 2 This study analysed the effects of incubation with noradrenaline (NA) and angiotensin II (Ang II) on prostanoid release in mesenteric vascular beds from control and fructose-fed rats. Animals which received fructose solution (10% w/v) for 22 weeks showed higher systolic blood pressure and triglyceridaemia. 3 In controls, NA increased 6-keto-prostaglandin (PG) F(1)alpha (prostacyclin metabolite) and thromboxane (TX) production. Ang II increased only TX release. In fructose-fed animals, NA increased 6-keto-PG F(1)alpha and TX. PGF(2)alpha (vasoconstrictor) was also elevated. Ang II also increased PGF(2)alpha and PGE(2) levels. 4 In conclusion, in fructose rats Ang II in vitro stimulates a vasoconstrictor prostanoid not stimulated in controls. This could be related to the observed in vivo blood pressure increase. In fructose-fed animals, NA and Ang II also augment vasodilator prostanoids, suggesting a compensatory mechanism because of long-term hypertension.
Assuntos
Angiotensina II/fisiologia , Endotélio Vascular/metabolismo , Frutose/administração & dosagem , Hipertensão/metabolismo , Norepinefrina/fisiologia , Prostaglandinas/metabolismo , Animais , Endotélio Vascular/efeitos dos fármacos , Frutose/toxicidade , Hipertensão/induzido quimicamente , Masculino , Mesentério/irrigação sanguínea , Mesentério/efeitos dos fármacos , Mesentério/metabolismo , Ratos , Ratos Sprague-DawleyRESUMO
BACKGROUND & AIMS: Visceral hypersensitivity, a hallmark of irritable bowel syndrome, is generally considered to be mechanosensitive in nature and mediated via spinal afferents. Both stress and inflammation are implicated in visceral hypersensitivity, but the underlying molecular mechanisms of visceral hypersensitivity are unknown. METHODS: Mice were infected with Nippostrongylus brasiliensis (Nb) larvae, exposed to environmental stress and the following separate studies performed 3-4 weeks later. Mesenteric afferent nerve activity was recorded in response to either ramp balloon distention (60 mm Hg), or to an intraluminal perfusion of hydrochloric acid (50 mmol/L), or to octreotide administration (2 micromol/L). Intraperitoneal injection of cholera toxin B-488 identified neurons projecting to the abdominal viscera. Fluorescent neurons in dorsal root and nodose ganglia were isolated using laser-capture microdissection. RNA was hybridized to Affymetrix Mouse whole genome arrays for analysis to evaluate the effects of stress and infection. RESULTS: In mice previously infected with Nb, there was no change in intestinal afferent mechanosensitivity, but there was an increase in chemosensitive responses to intraluminal hydrochloric acid when compared with control animals. Gene expression profiles in vagal but not spinal visceral sensory neurons were significantly altered in stressed Nb-infected mice. Decreased afferent responses to somatostatin receptor 2 stimulation correlated with lower expression of vagal somatostatin receptor 2 in stressed Nb-infected mice, confirming a link between molecular data and functional sequelae. CONCLUSIONS: Alterations in the intestinal brain-gut axis, in chemosensitivity but not mechanosensitivity, and through vagal rather than spinal pathways, are implicated in stress-induced postinflammatory visceral hypersensitivity.
Assuntos
Encéfalo/fisiologia , Intestinos/inervação , Mesentério/inervação , Nippostrongylus/patogenicidade , Infecções por Strongylida/metabolismo , Fibras Aferentes Viscerais/efeitos dos fármacos , Adjuvantes Imunológicos/farmacologia , Animais , Toxina da Cólera/farmacologia , Modelos Animais de Doenças , Feminino , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/metabolismo , Gânglios Espinais/fisiopatologia , Expressão Gênica/efeitos dos fármacos , Ácido Clorídrico/farmacologia , Mucosa Intestinal/metabolismo , Mesentério/efeitos dos fármacos , Mesentério/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Gânglio Nodoso/efeitos dos fármacos , Gânglio Nodoso/metabolismo , Gânglio Nodoso/fisiopatologia , Octreotida/farmacologia , Reação em Cadeia da Polimerase , RNA/genética , Receptores de Somatostatina/biossíntese , Receptores de Somatostatina/genética , Infecções por Strongylida/parasitologia , Infecções por Strongylida/patologia , Nervo Vago/efeitos dos fármacos , Nervo Vago/metabolismo , Nervo Vago/fisiopatologia , Fibras Aferentes Viscerais/metabolismoRESUMO
A strong association between the benefits of physical exercise on the cardiovascular disease with an improvement of the endothelium-derived relaxing factor production has been consistently shown. The purpose of this study was to evaluate the effect of exercise training associated with high caloric diet in the reactivity of rat mesenteric and aortic rings. Experimental protocol consisted of 4 weeks of high caloric diet consumption previous to 4 weeks of run training (1.2 km/h, 0% grade, in sessions of 60 min, 5 days/week). Concentrations of triglycerides, glucose, insulin and nitrite/nitrate levels were measured and atherogenic index was calculated. Concentration-response curves to acetylcholine (10 nM-100 microM), sodium nitroprusside (100 pM-100 nM) and phenylephrine (1 nM-3 microM) were obtained. Exercise training reduced body mass (6%) and triglyceride levels (about 54%), without changes in glucose and insulin concentrations. An improvement of endothelium-dependent relaxation responses to acetylcholine in mesenteric and aortic rings was observed in trained group. No changes were seen for sodium nitroprusside and phenylephrine. In conclusion, our study is the first to show clearly that run training promotes an improvement of the endothelium-dependent relaxing response in aorta and mesenteric rings from rats fed with high caloric diet and that is associated with increase of NO production.
Assuntos
Aorta/metabolismo , Dieta , Ingestão de Energia/fisiologia , Mesentério/metabolismo , Condicionamento Físico Animal , Acetilcolina/farmacologia , Animais , Aorta/efeitos dos fármacos , Glicemia/análise , Pressão Sanguínea/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Relação Dose-Resposta a Droga , Insulina/sangue , Lipídeos/sangue , Masculino , Mesentério/efeitos dos fármacos , Nitratos/sangue , Nitritos/sangue , Nitroprussiato/farmacologia , Tamanho do Órgão/efeitos dos fármacos , Fenilefrina/farmacologia , RatosRESUMO
Vascular disease is a major cause of mortality and morbidity in chronic diabetes mellitus. Prostanoids, metabolites of arachidonic acid, include vasoactive substances produced and released from the vascular wall. Alterations in prostanoid production have been reported in the vasculature of diabetic humans and experimental animals. The aim of the present work was to study the influence of three different periods of long-term streptozotocin-induced diabetes, 30, 120 and 180 days in the production of prostanoids in the thoracic aorta and in the mesenteric vascular bed of the rat. The prostanoids released to the incubation medium by the tissues were extracted and measured by reversed-phase HPLC. In the diabetic groups, body weight was reduced and glycaemia was increased when compared with the corresponding non-diabetic controls. In the aorta, 30 days of diabetes did not modify the prostanoid release pattern, meanwhile 120 and 180 days of incubation decreased prostacyclin (PGI(2)) production. In the mesenteric bed, at 30 days the release of the vasodilators PGI(2) and prostaglandin (PGE(2)) and the vasoconstrictor thromboxane (TXA(2)) was reduced. At 120 days the vasodilators were reduced and at 180 days such reduction was joined by an increase of the release of vasoconstrictor metabolites. Thirty days of diabetes did not modify the PGI(2)/TXA(2) ratio in the aorta or mesenteric bed. On the other hand, 120 and 180 days of diabetes reduced significantly the ratio when compared with the corresponding controls. In conclusion, the mesenteric bed, a resistance vascular bed, seems to be more sensitive than the aorta, a conductance vessel, to the effects of diabetes on prostanoid production. The observed effects contribute to a displacement of the balance of prostanoid release in favour of the vasoconstrictor metabolites, a phenomenon that could be related to the vascular complications of diabetes mellitus.
Assuntos
Aorta/metabolismo , Diabetes Mellitus Experimental/metabolismo , Mesentério/metabolismo , Prostaglandinas/biossíntese , Animais , Aorta/efeitos dos fármacos , Glicemia/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/induzido quimicamente , Técnicas In Vitro , Masculino , Mesentério/irrigação sanguínea , Mesentério/efeitos dos fármacos , Ratos , Ratos Wistar , Circulação Esplâncnica/efeitos dos fármacos , Estreptozocina/administração & dosagem , Estreptozocina/toxicidade , Tromboxano A2/biossíntese , Fatores de Tempo , Aumento de Peso/efeitos dos fármacos , Redução de Peso/efeitos dos fármacosRESUMO
OBJECTIVE: To analyze, in an existing cohort of infants, whether antenatal administered corticosteroids influence protein metabolism in preterm infants on the first day of life. Study design Three groups of infants were studied. The mothers of 25 infants had received 2 or more doses of corticosteroids, the mothers of 5 had received 1 dose, and there was no antenatal steroid exposure for 8 infants. Within a few hours after birth, a double-tracer leucine infusion was started by intravenous and intragastric routes and continued for 5 hours while the infants received only intravenous glucose. RESULTS: The plasma alpha-keto-isocaproic acid (KIC) enrichment (mol percent excess, MPE) from the intravenous tracer was not different between infants who reveived no antenatal steroids (8.58+/-1.64), 1 dose (7.60+/-0.78), and 2 or more doses (7.61+/-1.29). From the intragastric tracer, the plasma KIC enrichment from the intragastric tracer was different among the 3 groups, 7.62+/-2.35 for 0 doses, 5.78+/-0.85 for 1 dose, and 5.53+/-1.58 for 2 or more doses of antenatal steroids. Plasma KIC enrichment from the intravenous tracer was significantly higher than from the intragastric tracer in infants who received antenatal steroids, whereas there was no difference in infants who had not received antenatal steroids. Plasma leucine enrichment showed the same results. CONCLUSIONS: Antenatal corticosteroid administration to the fetus has no effect on whole-body leucine metabolism on the first day of life. However, it is associated with an increase in splanchnic leucine uptake at birth.
Assuntos
Betametasona/farmacologia , Trato Gastrointestinal/efeitos dos fármacos , Glucocorticoides/farmacologia , Recém-Nascido Prematuro/fisiologia , Leucina/metabolismo , Proteínas/metabolismo , Feminino , Humanos , Recém-Nascido , Infusões Intravenosas , Cetoácidos/metabolismo , Leucina/administração & dosagem , Mesentério/metabolismo , GravidezRESUMO
BACKGROUND: Human and rodent leukocytes express high levels of the glucocorticoid-inducible protein annexin 1 (ANXA1) (previously referred to as lipocortin 1). Neutrophils and monocytes have abundant ANXA1 levels. AIM: We have investigated, for the first time, ANXA1 ultrastructural expression in rat eosinophils and compared it with that of extravasated neutrophils. The effect of inflammation (carrageenin peritonitis) was also monitored. METHODS: Electron microscopy was used to define the sub-cellular localisation of ANXA1 in rat eosinophils and neutrophils extravasated in the mesenteric tissue. A pair of antibodies raised against the ANXA1 N-terminus (i.e. able to recognise intact ANXA1, termed LCPS1) or the whole protein (termed LCS3) was used to perform the ultrastructural analysis. RESULTS: The majority of ANXA1 was localised in the eosinophil cytosol (approximately 60%) and nucleus (30-40%), whereas a small percentage was found on the plasma membrane (< 10%). Within the cytosol, the protein was equally distributed in the matrix and in the granules, including those containing the typical crystalloid. The two anti-ANXA1 antibodies gave similar results, with the exception that LCPS1 gave a lower degree of immunoreactivity in the plasma membrane. Inflammation (i.e. carrageenin injection) produced a modest increase in eosinophil-associated ANXA1 reactivity (significant only in the cytoplasm compartment). Extravasated neutrophils, used for comparative purposes, displayed a much higher degree of immunoreactivity for the protein. CONCLUSION: We describe for the first time ANXA1 distribution in rat eosinophil by ultrastructural analysis, and report a different protein mobilisation from extravasated neutrophils, at least in this acute model of peritonitis.
Assuntos
Anexina A1/análise , Eosinófilos/química , Eosinófilos/ultraestrutura , Peritonite/imunologia , Animais , Modelos Animais de Doenças , Masculino , Mesentério/citologia , Mesentério/imunologia , Mesentério/metabolismo , Microscopia Imunoeletrônica , Neutrófilos/química , Neutrófilos/ultraestrutura , Peritonite/induzido quimicamente , Peritonite/metabolismo , Ratos , Ratos Sprague-DawleyRESUMO
Cancer cachexia causes disruption of lipid metabolism. Since it has been well established that the various adipose tissue depots demonstrate different responses to stimuli, we assessed the effect of cachexia on some biochemical and morphological parameters of adipocytes obtained from the mesenteric (MES), retroperitoneal (RPAT), and epididymal (EAT) adipose tissues of rats bearing Walker 256 carcinosarcoma, compared with controls. Relative weight and total fat content of tissues did not differ between tumor-bearing rats and controls, but fatty acid composition was modified by cachexia. Adipocyte dimensions were increased in MES and RPAT from tumor-bearing rats, but not in EAT, in relation to control. Ultrastructural alterations were observed in the adipocytes of tumor-bearing rat RPAT (membrane projections) and EAT (nuclear bodies)
Assuntos
Animais , Masculino , Ratos , Adipócitos/metabolismo , Tecido Adiposo/citologia , Caquexia/metabolismo , Carcinoma 256 de Walker/metabolismo , Adipócitos/ultraestrutura , Tecido Adiposo/metabolismo , Caquexia/patologia , Carcinoma 256 de Walker/patologia , Epididimo/citologia , Epididimo/metabolismo , Ácidos Graxos/análise , Lipídeos/análise , Mesentério/citologia , Mesentério/metabolismo , Peritônio/citologia , Peritônio/metabolismo , Proteínas/análise , Ratos Wistar , Espaço RetroperitonealRESUMO
Cancer cachexia causes disruption of lipid metabolism. Since it has been well established that the various adipose tissue depots demonstrate different responses to stimuli, we assessed the effect of cachexia on some biochemical and morphological parameters of adipocytes obtained from the mesenteric (MES), retroperitoneal (RPAT), and epididymal (EAT) adipose tissues of rats bearing Walker 256 carcinosarcoma, compared with controls. Relative weight and total fat content of tissues did not differ between tumor-bearing rats and controls, but fatty acid composition was modified by cachexia. Adipocyte dimensions were increased in MES and RPAT from tumor-bearing rats, but not in EAT, in relation to control. Ultrastructural alterations were observed in the adipocytes of tumor-bearing rat RPAT (membrane projections) and EAT (nuclear bodies).