Existence of α-Adrenoceptor Subtypes in Isolated Human Gastroepiploic and Omental Arteries

Establishing the existence of α-adrenoceptor subtypes in isolated human gastroepiploic and omental arteries was the goal of the present study. Functional vascular reactivity of selective α1- and α2-adrenoceptor agonists and antagonists was studied, using a cannula inserting technique. Intraluminal administration of norepinephrine (NE), phenylephrine (PE) or BHT-933 caused a vasoconstrictive response in a dose-related manner. The relative potencies of the 3 agonists were almost the same in both arteries. NE-induced vasoconstrictions were significantly antagonized by either prazosin or rauwolscine. PE-induced responses were strongly inhibited by prazosin. BHT-933-induced constrictions were inhibited by rauwolscine. These results indicate that both α1- and α2-adrenoceptors exist in the human gastroepiploic and omental arteries. (Circ J 2003; 67: 259 - 262)