RESUMO
BACKGROUND & AIMS: Sustained activation of the cytosolic calcium concentration induces injury to pancreatic acinar cells and necrosis. The calcium release-activated calcium modulator ORAI1 is the most abundant Ca(2+) entry channel in pancreatic acinar cells; it sustains calcium overload in mice exposed to toxins that induce pancreatitis. We investigated the roles of ORAI1 in pancreatic acinar cell injury and the development of acute pancreatitis in mice. METHODS: Mouse and human acinar cells, as well as HEK 293 cells transfected to express human ORAI1 with human stromal interaction molecule 1, were hyperstimulated or incubated with human bile acid, thapsigargin, or cyclopiazonic acid to induce calcium entry. GSK-7975A or CM_128 were added to some cells, which were analyzed by confocal and video microscopy and patch clamp recordings. Acute pancreatitis was induced in C57BL/6J mice by ductal injection of taurolithocholic acid 3-sulfate or intravenous' administration of cerulein or ethanol and palmitoleic acid. Some mice then were given GSK-7975A or CM_128, which inhibit ORAI1, at different time points to assess local and systemic effects. RESULTS: GSK-7975A and CM_128 each separately inhibited toxin-induced activation of ORAI1 and/or activation of Ca(2+) currents after Ca(2+) release, in a concentration-dependent manner, in mouse and human pancreatic acinar cells (inhibition >90% of the levels observed in control cells). The ORAI1 inhibitors also prevented activation of the necrotic cell death pathway in mouse and human pancreatic acinar cells. GSK-7975A and CM_128 each inhibited all local and systemic features of acute pancreatitis in all 3 models, in dose- and time-dependent manners. The agents were significantly more effective, in a range of parameters, when given at 1 vs 6 hours after induction of pancreatitis. CONCLUSIONS: Cytosolic calcium overload, mediated via ORAI1, contributes to the pathogenesis of acute pancreatitis. ORAI1 inhibitors might be developed for the treatment of patients with pancreatitis.
Assuntos
Células Acinares/efeitos dos fármacos , Benzamidas/farmacologia , Canais de Cálcio/efeitos dos fármacos , Canais de Cálcio/metabolismo , Cálcio/metabolismo , Pancreatite/tratamento farmacológico , Pirazóis/farmacologia , Células Acinares/citologia , Doença Aguda , Animais , Ácidos e Sais Biliares/toxicidade , Cálcio/toxicidade , Células Cultivadas , Modelos Animais de Doenças , Células HEK293 , Humanos , Indóis/toxicidade , Camundongos , Camundongos Endogâmicos C57BL , Proteína ORAI1 , Pancreatite/induzido quimicamente , Pancreatite/metabolismo , Tapsigargina/toxicidade , Fatores de Tempo , Resultado do TratamentoRESUMO
This study investigated the endothelium-dependent vasorelaxant effects of the essential oil of Ocimum gratissimum (EOOG) in aortas and mesenteric vascular beds isolated from rats. EOOG (3-300 µg/mL) relaxed the tonic contractions induced by phenylephrine (0.1 µmol/L) in isolated aortas in a concentration-dependent manner in both endothelium-containing and endothelium-denuded preparations. This effect was partially reversed by L-NAME (100 µmol/L) but not by indomethacin (10 µmol/L) or TEA (5 mmol/L). In mesenteric vascular beds, bolus injections of EOOG (30, 50, 100, and 300 ng) decreased the perfusion pressure induced by noradrenaline (6 µmol/L) in endothelium-intact preparations but not in those treated with deoxycholate. L-NAME (300 µmol/L) but not TEA (1 mmol/L) or indomethacin (3 µmol/L) significantly reduced the vasodilatory response to EOOG at all of the doses tested. Our data showed that EOOG exerts a dose-dependent vasodilatory response in the resistance blood vessels of rat mesenteric vascular beds and in the capacitance blood vessel, the rat aorta. This action is completely dependent on endothelial nitric oxide (NO) release in the mesenteric vascular beds but only partially dependent on NO in the aorta. These novel effects of EOOG highlight interesting differences between resistance and capacitance blood vessels.
Assuntos
Aorta Torácica/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Artérias Mesentéricas/efeitos dos fármacos , Veias Mesentéricas/efeitos dos fármacos , Ocimum/química , Óleos Voláteis/farmacologia , Vasodilatadores/farmacologia , Animais , Aorta Torácica/enzimologia , Aorta Torácica/metabolismo , Inibidores de Ciclo-Oxigenase/farmacologia , Endotélio Vascular/fisiologia , Técnicas In Vitro , Masculino , Artérias Mesentéricas/enzimologia , Artérias Mesentéricas/metabolismo , Veias Mesentéricas/enzimologia , Veias Mesentéricas/metabolismo , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/metabolismo , Norepinefrina/antagonistas & inibidores , Norepinefrina/metabolismo , Óleos Voláteis/química , Bloqueadores dos Canais de Potássio/farmacologia , Ratos , Ratos Wistar , Capacitância Vascular/efeitos dos fármacos , Resistência Vascular/efeitos dos fármacos , Vasoconstritores/antagonistas & inibidores , Vasoconstritores/farmacologia , Vasodilatação/efeitos dos fármacos , Vasodilatadores/antagonistas & inibidoresRESUMO
Bryothamnion seaforthii lectin (BSL) induced reversible concentration-related relaxation of endothelized aorta, maximal at 30 microg/ml (IC(50)= 4.8 +/- 0.6 microg/ml). This effect was inhibited by L-NAME and reversed by mucin, probably via interaction with a specific lectin-binding site on the endothelium activating nitric oxide synthase.
Assuntos
Proteínas de Algas/química , Endotélio Vascular/efeitos dos fármacos , Lectinas/farmacologia , Óxido Nítrico Sintase/metabolismo , Rodófitas/química , Análise de Variância , Animais , Aorta/metabolismo , Endotélio Vascular/enzimologia , Masculino , Relaxamento Muscular/efeitos dos fármacos , Músculo Liso Vascular/efeitos dos fármacos , Contração Miocárdica/efeitos dos fármacos , NG-Nitroarginina Metil Éster/farmacologia , Ratos , Ratos WistarRESUMO
OBJECTIVE: To evaluate potential in vitro relaxant actions of sildenafil on human isolated bladder neck smooth muscle. METHODS: Bladder neck strips were sampled from patients (aged 55-77 years) submitted to prostatic surgery (6 adenomectomies and 1 radical prostatectomy). These were carefully dissected into 1-2 x 0.5-cm pieces and suspended in an organ bath containing 30 mL of a modified Krebs Henseleit solution, bubbled with 95% O(2)/5% CO(2). After tissue stabilization and viability test with KCl, the tissue was precontracted with phenylephrine, and a concentration-response relaxant curve to sildenafil was constructed. The effect of sildenafil was also assessed in tissues treated with N(omega)-nitro-L-arginine methyl ester (L-NAME) or 1H-[1,2,4]oxadiazolo[4,3-a]quinoxaline-1-one (ODQ) (inhibitors of nitric oxide synthase and guanylyl cyclase, respectively). RESULT: Sildenafil induced significant bladder neck relaxation at all concentrations tested. The maximum relaxation was 86.97% +/- 6.69%, obtained with a high concentration of sildenafil (5.1 x 10(-4) M). Both L-NAME and ODQ significantly reduced sildenafil-induced relaxation. CONCLUSIONS: Sildenafil was effective in inducing bladder neck smooth muscle relaxation in vitro. This effect was almost abolished by L-NAME and ODQ, clearly demonstrating a dependence of the nitric oxide-cyclic guanosine monophosphate pathway. Our in-vitro results suggest that sildenafil might be useful in improving lower urinary tract symptoms due to benign prostatic hyperplasia.
Assuntos
Relaxamento Muscular/efeitos dos fármacos , Inibidores de Fosfodiesterase/farmacologia , Piperazinas/farmacologia , Sulfonas/farmacologia , Bexiga Urinária/efeitos dos fármacos , Bexiga Urinária/fisiologia , Idoso , Humanos , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , Purinas/farmacologia , Citrato de SildenafilaRESUMO
OBJECTIVE: To investigate the effects of sildenafil on noradrenaline- and potassium-induced contractions of isolated human seminal vesicles (SVs), as premature ejaculation is a relatively common male sexual dysfunction that currently lacks an adequate therapy, and recent in vitro tests showed that sildenafil induces relaxation of rodent isolated SVs, but it is not known whether it also inhibits isolated human SV. MATERIAL AND METHODS: Isolated strips of human SVs were suspended in an organ bath and cumulative concentration-response curves to either noradrenaline or KCl were constructed in the presence and absence of sildenafil to evaluate its inhibitory actions. RESULTS: Sildenafil (25-100 microm) induced concentration-dependent inhibitory effects on the human SV contracted by either noradrenaline or KCl. These actions of sildenafil do not therefore appear to be mediated via a competitive antagonism of alpha-adrenoceptors and are consistent with its recognized ability to inhibit phosphodiesterase-5. CONCLUSIONS: The present results show an important inhibitory action of sildenafil in the isolated human SV, supporting the therapeutic indication of this drug for treating premature ejaculation.
Assuntos
Contração Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Inibidores de Fosfodiesterase/farmacologia , Piperazinas/farmacologia , Glândulas Seminais/efeitos dos fármacos , Sulfonas/farmacologia , Idoso , Estudos de Casos e Controles , Humanos , Masculino , Pessoa de Meia-Idade , Contração Muscular/fisiologia , Músculo Liso/fisiologia , Norepinefrina/metabolismo , Cloreto de Potássio/metabolismo , Purinas/farmacologia , Glândulas Seminais/fisiologia , Citrato de SildenafilaRESUMO
Anethole is a naturally occurring aromatic oxidant, present in a variety of medicinal plant extracts, which is commonly used by the food and beverage industry. Despite its widespread occurrence and commercial use, there is currently little information regarding effects of this compound on the vasculature. Therefore the actions of anethole on the contractility of rat isolated aorta were compared with those of eugenol, and their respective isomeric forms, estragole and isoeugenol. In aortic rings precontracted with phenylephrine (PE; 1 microM), anethole (10(-6) M-10(-4) M) induced contraction in preparations possessing an intact endothelium, but not in endothelium-denuded tissues. At higher concentrations (10(-3) M-10(-2) M), anethole-induced concentration-dependent and complete relaxation of all precontracted preparations, irrespective of whether the endothelium was intact or not, an action shared by eugenol, estragole and isoeugenol. The contractile and relaxant effects of anethole in PE-precontracted preparations were not altered by L-NAME (10 microM) or indomethacin (10 microM), indicating that neither nitric oxide nor prostaglandins were involved in these actions. The mixed profile of effects was not confined to PE-mediated contraction, since similar responses were obtained to anethole when tissues were precontracted with 25 mM KCl. Anethole and estragole (10(-6)-10(-4) M), but not eugenol or isoeugenol, increased the basal tonus of endothelium-denuded aortic rings, an action that was abolished by VDCC blockers nifedipine (1 microM) and diltiazem (1 microM), or by withdrawal of extracellular Ca(2+). Our data suggest complex effects of anethole on isolated blood vessels, inducing contraction at lower doses, mediated via opening of voltage-dependent Ca(2+)-channels, and relaxant effects at higher concentrations that are shared by structural analogues.
Assuntos
Anisóis/farmacologia , Aorta/metabolismo , Canais de Cálcio/metabolismo , Aromatizantes/farmacologia , Contração Muscular/efeitos dos fármacos , Oxidantes/farmacologia , Derivados de Alilbenzenos , Animais , Cálcio/metabolismo , Cálcio/farmacologia , Fármacos Cardiovasculares/farmacologia , Diltiazem/farmacologia , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Indometacina/farmacologia , Masculino , Relaxamento Muscular/efeitos dos fármacos , Tono Muscular/efeitos dos fármacos , NG-Nitroarginina Metil Éster/farmacologia , Nifedipino/farmacologia , Técnicas de Cultura de Órgãos , Fenilefrina/farmacologia , Ratos , Ratos Wistar , Relação Estrutura-Atividade , Vasoconstrição/efeitos dos fármacos , Vasoconstritores/farmacologia , Vasodilatação/efeitos dos fármacos , Vasodilatadores/farmacologiaRESUMO
The effects of a lectin (AaL) from seeds of Araucaria angustifolia were investigated in the model of rat paw edema. In vivo anti-and pro-inflammatory activities, role of sugar residues, inflammatory mediators and systemic toxicity were assessed. Intravenous injection of AaL (0.1-1 mg/kg) dose-dependently inhibited the dextran-induced increase in edema and vascular permeability, which were prevented by association of the lectin with its binding sugar N-acetyl-glucosamine (Glyc-Nac). AaL also significantly inhibited edema induced by serotonin (18%) and compound 48/80 (33%), but not edema induced by histamine. In contrast, when applied by the s.c. route, AaL evoked a paw edema that peaked 1 h later and was partially prevented by association with Glyc-Nac (59%) or by prior i.v. administration of the lectin itself (38.8%). This AaL edematogenic activity was significantly inhibited by pentoxifylline (44.4%) or dexamethasone (51%) and also by depletion of rat paw mast cells (45.6%), but not by L-N-nitro-arginine methyl ester or indomethacin, excluding involvement of nitric oxide and prostaglandins. Treatment of animals with a single anti-inflammatory dose of AaL (1 mg/kg, i.v.) for 7 days did not affect rat corporal mass, liver, kidney, spleen or stomach wet weight, blood leukocyte count, and urea, creatinine or serum transaminase activity. Systemic toxicity was apparent only at much higher doses (LD50=88.3 mg/kg) than those required for the anti-inflammatory effect. Summarizing, AaL exerts anti-and pro-edematogenic actions via interaction with its specific lectin domain. These actions may share a common pathway involving either activation or inhibition of inflammatory mediators from resident mast cells.
Assuntos
Anti-Inflamatórios/farmacologia , Quitina/metabolismo , Mastócitos/fisiologia , Lectinas de Plantas/farmacologia , Sementes/química , Traqueófitas/química , Doença Aguda , Animais , Permeabilidade Capilar/efeitos dos fármacos , Relação Dose-Resposta a Droga , Edema/prevenção & controle , Histamina/farmacologia , Masculino , Pentoxifilina/farmacologia , Ratos , Ratos Wistar , Serotonina/farmacologia , p-Metoxi-N-metilfenetilamina/farmacologiaRESUMO
This work evaluated the antinociceptive effect of proteins from the Calotropis procera (Asclepiadaceae) latex using three different experimental models of nociception in mice. The latex protein fraction administered intraperitoneally in male mice at the doses of 12.5, 25 and 50 mg/kg showed the antinociceptive effect in a dose dependent manner compared to the respective controls in all assays. Inhibitions of the acetic acid-induced abdominal constrictions were observed at the doses of 12.5 (67.9%), 25 (85%) and 50 (99.5%) mg/kg compared to controls. Latex protein at the doses of 25 (39.8%; 42%) and 50 mg/kg (66.6%; 99.3%) reduced the nociception produced by formalin in the 1st and 2nd phases, respectively, and this effect was not reversed by pretreatment with naloxone (1 mg/kg). In the hot plate test, an increase of the reaction time was observed only at 60 min after the treatment with latex at the doses of 25 (79.5%) and 50 (76.9%) mg/kg, compared to controls and naloxone was ineffective to reverse the effect. It was concluded that the protein fraction derived from the whole latex of Calotropis procera possesses antinociceptive activity, which is independent of the opioid system.
Assuntos
Analgésicos/farmacologia , Calotropis/química , Látex/farmacologia , Ácido Acético , Animais , Relação Dose-Resposta a Droga , Formaldeído , Temperatura Alta , Masculino , Camundongos , Naloxona/farmacologia , Antagonistas de Entorpecentes/farmacologia , Medição da Dor/efeitos dos fármacos , Proteínas de Plantas/química , Proteínas de Plantas/farmacologia , Tempo de Reação/efeitos dos fármacosRESUMO
We have investigated the vascular relaxant effects of the lectin from a red marine alga Bryothamnion triquetrum (BTL), in particular, the endothelial-dependency and the participation of a specific glycoprotein-binding site. BTL (1-100 microg mL(-1)) was applied to rat isolated aortic rings, with or without endothelium, tonically precontracted with phenylephrine (0.1 microM). Endothelium-dependent relaxation was assessed in the presence of indometacin (10 microM), L-nitro arginine methyl ester (L-NAME, 100 microM) and tetraethylammonium (TEA, 500 microM). For the involvement of the glycoprotein-binding site, BTL was assayed in presence of mucin (300 microg mL(-1)) or N-acetyl D-glucosamine (GlcNAc; 300 microg mL(-1)), a specific and non-specific lectin-binding sugar, respectively. BTL fully and concentration dependently relaxed preparations that possessed an intact endothelium (IC50 (concn producing 50% contraction) = 12.1 +/- 1.6 microg mL(-1)), whereas no significant relaxation was observed in endothelial-denuded tissue. L-NAME, but not indometacin or TEA, completely inhibited the lectin relaxation, suggesting the involvement of nitric oxide (NO). The lectin in association with mucin, but not with GlcNAc, inhibited BTL-induced relaxation, implicating the involvement of the lectin binding site. Our data suggest that the relaxant effect of the red marine alga Bryothamnion triquetrumlectin on isolated aorta occurs via interaction with a specific lectin-binding site on the endothelium, resulting in a release of NO.
Assuntos
Lectinas/farmacologia , Óxido Nítrico/metabolismo , Extratos Vegetais/farmacologia , Rodófitas/química , Animais , Aorta/efeitos dos fármacos , Aorta/fisiologia , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiologia , Técnicas In Vitro , Lectinas/isolamento & purificação , Masculino , Relaxamento Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Músculo Liso/fisiologia , Óxido Nítrico/farmacologia , Ratos , Ratos Wistar , Receptores Mitogênicos/fisiologiaRESUMO
1. We have investigated the inhibitory effects of blockers of volume-activated (Cl(vol)) and calcium-activated (Cl(Ca)) chloride channels on hypotonic solution (HS)-induced contractions of rat trachea, comparing their effects with those of the voltage-dependent calcium channel (VDCC) blocker nifedpine. 2. HS elicited large, stable contractions that were partially dependent on the cellular chloride gradient; a reduction to 41.45+/-7.71% of the control response was obtained when extracellular chloride was removed. In addition, HS-induced responses were reduced to 26.8+/-5.6% of the control by 1 microm nifedipine, and abolished under calcium-free conditions, indicating a substantial requirement for extracellular calcium entry, principally via VDCCs. 3. The established Cl(vol) blockers tamoxifen (
Assuntos
Canais de Cloreto/antagonistas & inibidores , Canais de Cloreto/fisiologia , Soluções Hipotônicas/farmacologia , Contração Muscular/efeitos dos fármacos , Traqueia/efeitos dos fármacos , Animais , Masculino , Contração Muscular/fisiologia , Nifedipino/farmacologia , Ácido Niflúmico/farmacologia , Ratos , Ratos Wistar , Tamoxifeno/farmacologia , Traqueia/fisiologiaRESUMO
The effects of the essential oil of Ocimum gratissimum L. (Labiatae) (EOOG) on guinea pig ileum were studied. EOOG (0.1-1000 microg/ml) reversibly and concentration-dependently relaxed the basal tone of the ileum and reversed the tonic contractions induced by 60 mM KCl and 10 microM acetylcholine, with IC(50) values of 23.8+/-5.2, 18.6+/-4.0 and 70.0+/-4.6 microg/ml, respectively. Our results show that EOOG exerts relaxant effects on intestinal smooth muscle, consistent with the popular use of the plant to treat gastrointestinal disorders.
Assuntos
Íleo/efeitos dos fármacos , Íleo/fisiologia , Relaxamento Muscular/efeitos dos fármacos , Ocimum/química , Óleos Voláteis/farmacologia , Acetilcolina/farmacologia , Animais , Cobaias , Concentração Inibidora 50 , Masculino , Contração Muscular/efeitos dos fármacos , Tono Muscular/efeitos dos fármacos , Parassimpatolíticos/farmacologia , Cloreto de Potássio/farmacologiaRESUMO
Novel derivatives of 2-[3-(trifluoromethyl)-analino]nicotinic acid (niflumic acid) were synthesized. The compounds were compared for their inhibitory effects on 5-hydroxytryptamine (5-HT)- and KCI-induced contraction of the rat fundus. The aim was to assess structure-activity relationships regarding the selectivity and potency of these compounds. Niflumic acid (1-100 microM) concentration-dependently inhibited 5-HT-induced tonic contractions with an IC50 value (concentration reducing the control contractile response by 50%, calculated from semi-log graphs) of 0.24 x 10(4) M (n = 9). In contrast, it was significantly less potent at inhibiting KCl-induced responses (IC50 = 1.49 x 10(4) M, n = 9). The methyl ester (NFAme) and amido (NFAm) analogues showed no selectivity between 5-HT- and KCl-induced contractions with IC50 values of 1.64 x 10(-4) M (n = 8) and 1.87 x 10(-4) M (n = 9) for 5-HT responses, and 2.61 x 10(-4) M (n = 8) and 2.55 x 10(-4) M (n = 7) for KCl-induced responses, respectively. Our results suggest that alteration of the carboxylic acid moiety of niflumic acid reduces the selectivity and potency of its inhibitory action on 5-HT-induced contractile responses of the rat fundus, possibly via a reduced interaction with calcium-activated chloride channels.