Cardiovascular dopamine receptors: recent advances in agonists and antagonists of the DA1-receptor.

Until recently, the key pharmacologic tools necessary for major advances in understanding and studying cardiovascular and renal dopamine receptors have been lacking. This communication describes new advances in the pharmacology of dopamine receptors as studied with a series of newly synthetized benzazepines. Fenoldopam (SK&F 82526) is a selective (DA1) dopamine-receptor agonist. Initial studies with fenoldopam on splenic arterial ring segments of the rabbit have suggested that the endothelium as well as vascular smooth muscle may possess hemodynamically important dopamine receptors, and that cyclic adenosine monophosphate can be a second messenger mediating dopaminomimetic vasodilatation. Significant advances in DA1-selective antagonists have also recently been made. SK&F 83566 is a potent antagonist of both dopamine and fenoldopam in the vasculature. Dopamine-receptor selective agonists and antagonists represent an emerging strategy for the treatment of several cardiovascular diseases, including hypertension and edema. Moreover, these compounds are important tools for the characterization and study of dopamine receptors.