ENDOTHELIUM-DEPENDENT AND INDEPENDENT EFFECTS OF GARLIC ON RAT AORTA

Effects of garlic on isolated rat aorta were investigated by comparing with those of acetylcholine and L-arginine in the presence and absenc e of endothelium. For this purpose, certain linear and non-linear regr ession models were applied for concentration-response curves obtained by acetylcholine, L-arginine and garlic in the rat aorta. Garlic cause d dose-dependent relaxations in isolated rat aorta which were attenuat ed by the removal of endothelium as in the case of acetylcholine. Howe ver, the relaxant responses to acetylcholine, L-arginine and garlic we re not completely abolished by the endothelial denudation. Application of a number of regression models for the vasorelaxant effects of acet ylcholine and garlic revealed that mechanism(s) of the effect of garli c may be different from that of acetylcholine. Furthermore, it was not ed that L-arginine-induced relaxations, but not those induced by acety lcholine and garlic, are enhanced by a 2 or 4 h incubation period in t he bathing medium. The findings obtained strongly suggested that the v asorelaxant effect of garlic is important in its hypotensive activity and mediated by the production of endothelium-and/or muscle-derived re laxing factors.