Evidence that specific dopamine-1 receptor activation is involved in dopamine-induced renin release.
Direct effects of dopamine on renin release were examined using static incubations and perifusions of rat renal cortical slices. Dopamine (10(-5)M) significantly stimulated renin release compared with control. To determine which receptors are involved in dopamine-elicited renin release, studies were performed with specific dopamine-1 and dopamine-2 receptor agonists and antagonists, as well as with alpha- and beta-adrenergic antagonists. Fenoldopam, a dopamine-1 receptor agonist, dose dependently stimulated renin secretion both in static incubations and perifusions; whereas quinpirole (10(-7)-10(-5)M), a dopamine-2 receptor agonist, was ineffective. Phentolamine (10(-4)M), an alpha-adrenergic antagonist, did not alter dopamine- or fenoldopam-induced renin release. Similarly, propranolol, a beta-blocker, did not interfere with the renin stimulation of dopamine (10(-5)M) or fenoldopam (10(-6)M) incubations or perifusion experiments; whereas propranolol significantly blocked isoproterenol action. SCH 23390 (10(-5)M), a specific dopamine-1 antagonist, blocked dopamine- and fenoldopam-induced renin. In contrast, pimozide, a dopamine-2 receptor antagonist, was ineffective. These studies indicate that dopamine is a direct renin secretogogue, and its effects seem to be mediated by specific dopamine-1 receptor activation, as neither alpha- nor beta-adrenergic blockers nor dopamine-2 receptor antagonists altered dopamine actions. The results suggest that dopamine produced locally in the kidney may stimulate renin secretion directly by dopamine-1 receptor activation.
Antonipillai
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Section of Endocrinology, LAC/USC Medical Center, 90033.
Broers
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MI
Lang
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D
D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D004298:Dopamine / Q000494:pharmacology*; D004873:Ergolines / Q000494:pharmacology; D018818:Fenoldopam; D007668:Kidney / Q000378:metabolism; D008297:Male; D010646:Phentolamine / Q000494:pharmacology; D010868:Pimozide / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D019257:Quinpirole; D051381:Rats; D011954:Receptors, Dopamine / Q000378:metabolism*; D017447:Receptors, Dopamine D1; D012083:Renin / Q000378:metabolism*
D001552:Benzazepines; D004873:Ergolines; D011954:Receptors, Dopamine; D017447:Receptors, Dopamine D1; D010868:Pimozide; D019257:Quinpirole; D011433:Propranolol; D012083:Renin; D018818:Fenoldopam; D004298:Dopamine; D010646:Phentolamine