Effects of some dopamine analogs and haloperidol on response to stimulation of adrenergic nerves using cat atria in vitro.

Dopamine analogs, N, N-dimethyldopamine, apomorphine and 5,6-dihydroxy-2-dimethylaminotetralin (M-7) produced inhibition of positive chronotropic and inotropic responses to transmural stimulation of isolated right atria of cats. Haloperidol antagonized inhibitory effects of dopamine analogs. Also haloperidol increased atrial responses during transmural stimulation. N,N-dimethyldopamine, M-7 and apomorphine did not alter responses to exogenous norepinephrine. Haloperidol did not antagonize the inhibitory effect of clonidine.