Article: PDF OnlyHughes A.; Inkpen, P.; Sever, P.Journal of Cardiovascular Pharmacology: March 1988 - p 373 Free Abstract Summary We have investigated the subtype of α-adrenoceptor responsible for the contractile effect of dopanine using isolated human saphenous vein. Lengths of aphenous vein were obtained surplus to coronary artery ypass graft operations and studied as intact rings using a onventional organ bath technique. Contractile responses to dopamine (10−7–10−3M) in the presence of propranolol, cocaine, and 17β oestradiol were competitively antagonised by the α2-selective adrenoceptor an-agonist yohimbine (10−8–10−6M) but unaffected by the α1 selective adrenoceptor antagonist doxazosin (10−8–10−6M), whereas the response to norepinephrine (NE) (10−8–10−3M) was antagonised by doxazosin (10−8–10−6M), thus demonstrating the presence of α1 -adrenoceptors in this preparation. We conclude that the contractile effects of dopamine in isolated human saphenous vein are mediated predominantly by an action on α2-adrenoceptors. © Lippincott-Raven Publishers.