Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE: BYANKA PORTO FRAGA
DATA: 03/12/2012
HORA: 09:00
LOCAL: SALA DE VÍDEO CONFERÊNCIA DA RENORBIO
TÍTULO:
'' OBTENÇÃO DE COMPLEXO DE INCLUSÃO (GERANIOL EM BETA-CICLODEXTRINA ) E AVALIAÇÃO DO SEU EFEITO SOBRE O SISTEMA CARDIOVASCULAR DE RATOS''
geraniol, vasorelaxant effect, rat mesenteric artery
Geraniol is a monoterpene found in various herbs with activity on the cardiovascular system. The objective of the present study was to evaluate the vasorelaxant effect induced by geraniol in rat mesenteric artery. Male Wistar rats (200 – 300g) were euthanized and superior mesenteric artery was removed and cut in rings, which were mounted in organ baths containing 10 mL of Tyrode's solution at 37°C and gassed with carbogen. For isometric tension recordings, each ring was fixed in a force transducer connected to an acquisition system. In rat mesenteric artery rings with functional endothelium pre-contracted with of phenylephrine (10 µM), geraniol (10-8 – 10-2 M) was able to induce relaxation (Emax = 110 ± 5%; n = 6) which was not attenuated after removal of endothelium (Emax = 108 ± 6 %; n = 6) or after tetraethylammonium (1 mM), a non-selective blocker of K+ channels (Emax = 109 ± 3%; n = 6). In endothelium-denuded rings pre-contracted with KCl 80 mM, geraniol produced a relaxation (Emax = 142 ± 14%; n = 6) that was significantly (p<0.05) higher than those obtained in rings with functional endothelium pre-contracted with phenylephrine. Futhermore, the incubation with 3 x 10-4 or 10-3 M of geraniol antagonized the tonic contractions induced by CaCl2 (10-7 – 3 x 10-2M) and phasic contractions induced by phenylephine in without calcium solution. In conclusion, geraniol produces vasorelaxation by inhibiting the Ca2+ influx and Ca2+ release through phenylephrine sensitive intracellular Ca2+stores and, this effect, is endothelium-independent.