Different antagonistic effects of bunazosin and ketanserin on the norepinephrine-induced vasoconstriction in isolated, perfused canine and simian skeletal muscle arteries.

Blocking activities of bunazosin and ketanserin on norepinephrine (NE)-induced vasoconstrictions were investigated in isolated, perfused canine and simian skeletal muscle arteries. NE caused an increase in perfusion pressure in a dose-related manner to almost the same extent in both canine and simian arterial preparations. Bunazosin and ketanserin inhibited NE-induced vasoconstrictions much more readily in simian arteries than in canine arteries. The mechanisms for the different adrenolytic activities of alpha 1-antagonists between these two arteries were discussed.