Rat juxtaglomerular cells are endowed with DA-1 dopamine receptors mediating renin release.
Under control conditions a primary culture containing about 80-90% of granular juxtaglomerular (JG) cells prepared from rat kidneys continuously released renin into the culture medium at a rate of 17.9 +/- 1.4 ng angiotensin I/h per mg of cell proteins per 30 min (n = 14). Dopamine (1.0 microM), the DA-1 dopamine receptor agonist fenoldopam (0.5 microM), and isoproterenol (1.0 microM) increased renin secretion markedly (130-200%). Propranolol (0.1 microM) reduced the effects of isoproterenol significantly (80%), but not those of dopamine or fenoldopam. In contrast, SCH 23390 (0.01 microM), a DA-1 dopamine receptor antagonist, inhibited markedly only the renin release evoked by the latter two agonists, whereas S-sulpiride (10 microM), a DA-2 dopamine receptor antagonist, and phentolamine (10 microM), a nonselective alpha-adrenoceptor antagonist, did not modify the effects of either dopamine or fenoldopam. In rats, pithed to eliminate reflexogenic mechanisms regulating renin release, at the end of a 15 min i.v. infusion of fenoldopam (20 micrograms/kg per min) there was a significant increase in plasma renin activity. This effect was completely prevented by SCH 23390 (0.1 mg/kg i.v.) but not significantly changed by S-sulpiride (0.3 mg/kg i.v.) or phentolamine (3.0 mg/kg i.v.) plus propranolol (0.75 mg/kg i.v.). In conclusion, these results indicate that DA-1 dopamine receptors are present in rat kidney JG cells and that pharmacological stimulation of these receptors with dopamine or fenoldopam leads to renin secretion.
Kurtz
A
A
Physiologisches Institut, Universität Zürich, Switzerland.
Della Bruna
R
R
Pratz
J
J
Cavero
I
I
D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D003655:Decerebrate State; D004298:Dopamine / Q000494:pharmacology; D018818:Fenoldopam; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D007606:Juxtaglomerular Apparatus / Q000166:cytology / Q000378:metabolism*; D008297:Male; D010646:Phentolamine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000378:metabolism*; D012083:Renin / Q000378:metabolism*; D013469:Sulpiride / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology
D001552:Benzazepines; D011954:Receptors, Dopamine; D014665:Vasodilator Agents; D013469:Sulpiride; D012083:Renin; D018818:Fenoldopam; D007545:Isoproterenol; D004298:Dopamine; D010646:Phentolamine