2 research outputs found

    Comparison of the hypotensive effect induced by the ethanol extract of <i>Albizia inopinata</i> G. P. Lewis in normotensive and chronically L-NAME hypertensive rats

    No full text
    El objetivo del presente estudio fue caracterizar la respuesta hipotensora provocada por la fracci贸n acuosa del extracto etan贸lico de hojas (AFL) de Albizia inopinata en ratas normotensas y hipertensas por el L-NAME (N-nitro-L-argininA metil茅ster). En las ratas normotensas, AFL provoc贸 una disminuci贸n dosis-dependiente de la presi贸n arterial, acomp茫nada de un aumento de la frecuencia card铆aca. Ya en el caso de las ratas hipertensas, AFL provoc贸 una hipotensi贸n m谩s aguda, en tanto que las modificaciones de la frecuencia card铆aca no fueron significativas. En los anillos de la aorta, concentraciones crecientes de AFL antagonizaron las contracciones provocadas por fenilefrina y KCl; por otro lado, los valores de CI 50 para ratas normotensas fueron significantemente superiores a los obtenidos en ratas hipertensas. El efecto vasodilator de AFL parece ser claramente dependiente de la liberaci贸n de NO por el endotelio vascular. En conclusi贸n, el presente estudio demuestra que AFL disminuye la presi贸n arterial en ratas normotensas e hipertensas, debido probablemente a una disminuci贸n de la resistencia perif茅rica total. El efecto hipotensor mayor observado en ratas hipertensas es causado probablemente por una vasodilataci贸n potencializada, provocada por AFL.The aim of this study was to characterize the hypotensive response induced by the aqueous fraction of the ethanolic extract of the leaves (AFL) of Albizia inopinata in normotensive and chronically L-NAME-hypertensive rats. AFL induced dosedependent decreases in mean blood pressure (MAP) in both cases, however, hypotension was more pronounced in hypertensive rats. In isolated rat aortic rings, increasing concentrations of AFL were able to antagonize phenylephrine and KCl-induced contractions, however, IC 50 values for normotensive rats were significantly higher than that obtained for hypertensive rats. Furthermore, AFL-induced response was clearly endothelium-dependent since after removal of aortic endotelial cells and NO-synthase blockade, the relaxant response was significantly attenuated. The present work demonstrates that in normotensive and L-NAME-hypertensive rats, AFL lowers MAP, probably due to a decrease in peripheral resistances. The more pronounced hypotensive effect observed in hypertensive rats, is probably due to a strong vasodilation induced by AFL in these rats.Colegio de Farmac茅uticos de la Provincia de Buenos Aire

    Comparison of the hypotensive effect induced by the ethanol extract of <i>Albizia inopinata</i> G. P. Lewis in normotensive and chronically L-NAME hypertensive rats

    No full text
    El objetivo del presente estudio fue caracterizar la respuesta hipotensora provocada por la fracci贸n acuosa del extracto etan贸lico de hojas (AFL) de Albizia inopinata en ratas normotensas y hipertensas por el L-NAME (N-nitro-L-argininA metil茅ster). En las ratas normotensas, AFL provoc贸 una disminuci贸n dosis-dependiente de la presi贸n arterial, acomp茫nada de un aumento de la frecuencia card铆aca. Ya en el caso de las ratas hipertensas, AFL provoc贸 una hipotensi贸n m谩s aguda, en tanto que las modificaciones de la frecuencia card铆aca no fueron significativas. En los anillos de la aorta, concentraciones crecientes de AFL antagonizaron las contracciones provocadas por fenilefrina y KCl; por otro lado, los valores de CI 50 para ratas normotensas fueron significantemente superiores a los obtenidos en ratas hipertensas. El efecto vasodilator de AFL parece ser claramente dependiente de la liberaci贸n de NO por el endotelio vascular. En conclusi贸n, el presente estudio demuestra que AFL disminuye la presi贸n arterial en ratas normotensas e hipertensas, debido probablemente a una disminuci贸n de la resistencia perif茅rica total. El efecto hipotensor mayor observado en ratas hipertensas es causado probablemente por una vasodilataci贸n potencializada, provocada por AFL.The aim of this study was to characterize the hypotensive response induced by the aqueous fraction of the ethanolic extract of the leaves (AFL) of Albizia inopinata in normotensive and chronically L-NAME-hypertensive rats. AFL induced dosedependent decreases in mean blood pressure (MAP) in both cases, however, hypotension was more pronounced in hypertensive rats. In isolated rat aortic rings, increasing concentrations of AFL were able to antagonize phenylephrine and KCl-induced contractions, however, IC 50 values for normotensive rats were significantly higher than that obtained for hypertensive rats. Furthermore, AFL-induced response was clearly endothelium-dependent since after removal of aortic endotelial cells and NO-synthase blockade, the relaxant response was significantly attenuated. The present work demonstrates that in normotensive and L-NAME-hypertensive rats, AFL lowers MAP, probably due to a decrease in peripheral resistances. The more pronounced hypotensive effect observed in hypertensive rats, is probably due to a strong vasodilation induced by AFL in these rats.Colegio de Farmac茅uticos de la Provincia de Buenos Aire
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