title: Presynaptic dopamine receptors in the cardiovascular system.
abstract: Stimulation by agonists of presynaptic dopamine receptors on nerve terminals of peripheral sympathetic neurons results in inhibition of norepinephrine release and a concomitant reduction of end organ responses to sympathetic nerve stimulation. These presynaptic dopamine receptors are of the DA-2 subtype and can be blocked selectively by the antagonist S-sulpiride. Presynaptic DA-2 receptors are the target of action of agonists with potential antihypertensive and bradycardic effects. Under control conditions exposure to S-sulpiride on its own does not enhance norepinephrine release. Following chronic treatment of cats with pargyline, S-sulpiride produced a small but significant increase in the electrically-evoked release of 3H-norepinephrine from perfused atrial slices. The possible involvement of peripheral presynaptic DA-2 receptors in the antihypertensive effects of monoamine oxidase inhibitors is discussed.
mesh_terms: D000818:Animals; D002320:Cardiovascular Physiological Phenomena; D002415:Cats; D004298:Dopamine / Q000378:metabolism; D004558:Electric Stimulation; D004873:Ergolines / Q000494:pharmacology; D066298:In Vitro Techniques; D009206:Myocardium / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism; D010293:Pargyline / Q000494:pharmacology; D019257:Quinpirole; D051381:Rats; D011954:Receptors, Dopamine / Q000502:physiology*; D013152:Splanchnic Circulation / Q000187:drug effects; D013469:Sulpiride / Q000494:pharmacology; D013564:Sympathetic Nervous System / Q000502:physiology; D013569:Synapses / Q000502:physiology; D014661:Vasoconstriction
chemical_list: D004873:Ergolines; D011954:Receptors, Dopamine; D019257:Quinpirole; D013469:Sulpiride; D010293:Pargyline; D004298:Dopamine; D009638:Norepinephrine