RESUMO
OBJECTIVE: To study the influence of sex on the responses of microvessels to vasoactive agents in experimental diabetes. MATERIALS: Diabetes was induced by alloxan (40 mg/kg, iv) in male and female Wistar rats (8-10-week-old). METHODS: Using an image splitter television microscope, mesenteric arteriolar and venular diameter changes induced by topically applied vasoactive agents (histamine, bradykinin, platelet activating factor-PAF, acetylcholine, sodium nitroprusside, noradrenaline and angiotensin II) were examined. RESULTS: Whereas the vasoconstrictor response to noradrenaline was equivalent in normal and diabetic animals, either female or male rats, an increased vasoconstrictor response to angiotensin II was observed in male but not in female diabetic rats in comparison with respective controls. Similarly to that observed in males, the dilator response of microvessels to topically applied bradykinin, histamine and PAF was impaired in female diabetic rats. Whereas reversal of the impaired responses to these agents was obtained by acute treatment of diabetic animals with insulin the altered responses to angiotensin II observed in male diabetic rats were not corrected. Differently from that observed in males, impaired response of microvessels to acetylcholine but not to sodium nitroprusside was observed in female diestrous diabetic rats; acute insulin treatment corrected it. CONCLUSIONS: We conclude that not all the alterations of the microvascular reactivity and the correction by insulin are gender dependent in diabetes.
Assuntos
Diabetes Mellitus Experimental/fisiopatologia , Acetilcolina/farmacologia , Angiotensina II/farmacologia , Animais , Peso Corporal/efeitos dos fármacos , Bradicinina/farmacologia , Ciclo Estral/efeitos dos fármacos , Feminino , Histamina/farmacologia , Hipoglicemiantes/farmacologia , Insulina/farmacologia , Masculino , Microcirculação/anatomia & histologia , Microcirculação/efeitos dos fármacos , Microcirculação/fisiopatologia , Nitroprussiato/farmacologia , Norepinefrina/farmacologia , Tamanho do Órgão/efeitos dos fármacos , Fator de Ativação de Plaquetas/farmacologia , Ratos , Ratos Wistar , Caracteres Sexuais , Útero/efeitos dos fármacos , Vasoconstritores/farmacologia , Vasodilatadores/farmacologiaRESUMO
The antiulcer activity of the total extract and the fractions of Stryphnodendron adstringens was studied in rats and compared with that of cimetidine. Ulcers were induced in rats by means of three experimental models: acute stress, acidified-ethanol and indomethacin. The total extract and the fractions were found to have significant antiulcer activity in the case of the acute stress and acidified-ethanol models. These findings support the use of S. adstringens extracts in the treatment of gastric lesions.