when the adrenoceptor blockers were added sequentially , both alpha and beta adrenoceptor-mediated components in the inotropic response to norepinephrine could be demonstrated : one beta adrenoceptor-mediated component ( timolol sensitive only ) that represented about 75 % of the inotropic response and one alpha adrenoceptor-mediated component ( prazosin sensitive only ) that represented about 25 % of the inotropic response .
C0001643
beta
C0034783
adrenoceptor