Vasorelaxant effect of 17α-ethynylestradiol on human saphenous vein.

Purpose: A protective effect for estrogens against cardiovascular problems has long been known. The aim of this study was to investigate the vasorelaxant effect of 17α-Ethynylestradiol (17α-EE) on human saphenous vein.

Methods: The veins were suspended horizontally between two triangular stainless steel hooks for the measurement of isometric tension in individual organ baths containing 10ml Krebs solution, at 37°C and gassed with carbogen under 3gr optimum tension.

Allopurinol prevents nitroglycerin-induced tolerance in rat thoracic aorta.

Xanthine oxidase is an important source of reactive oxygen species; so, it may play a role in the pathogenesis of endothelium dysfunction and its consequences. Allopurinol, a purine analog, is a famous xanthine oxidase inhibitor. This study aimed to investigate possible effects of allopurinol on nitroglycerin tolerance, vasoconstriction, and vasorelaxation in rat aortic ring.