Oxytocin-induced renin secretion by denervated kidney in anaesthetized rat.
The effects of oxytocin on renin secretion by denervated kidney were investigated in vivo, by infusing the peptide directly into the renal artery of anaesthetized rats. Renin secretion was calculated by the renal veno-arterial difference in plasma renin activity multiplied by renal plasma flow. The intra-renal arterial (i.r.a.) infusion of oxytocin (1.5 or 15 ng/kg/min, 10 min) induced a sixfold increase in renin secretion as compared to vehicle-treated controls, without effects on renal blood flow, mean arterial blood pressure, glomerular filtration rate or natriuresis. The effect of oxytocin (1.5 ng/kg/min) was prevented by pretreatment with an oxytocin receptor antagonist, desGly-NH(2),d(CH(2))(5)[D-Tyr(2),Thr(4),Orn(8)]vasotocin] (5.6 microg/kg bolus i.v. 20 min before oxytocin infusion, followed by 2.8 microg/kg/min i.r.a.). Nadolol (2.5 mg/kg i.v.), a beta-adrenoceptor antagonist, also blocked the oxytocin-induced increase in renin secretion. These results show that oxytocin is able to stimulate renin release by activating oxytocin receptors but that beta-adrenoceptors also seem to be involved.
Loichot
Cécile
C
Institut de Pharmacologie, Faculté de Médecine, Université Louis Pasteur, 11 Rue Humann, 67085 Strasbourg Cedex, France.
Grima
Michèle
M
De Jong
Wybren
W
Helwig
Jean-Jacques
JJ
Imbs
Jean-Louis
JL
Barthelmebs
Mariette
M
D000777:Anesthetics / Q000494:pharmacology*; D000818:Animals; D003714:Denervation; D007668:Kidney / Q000187:drug effects* / Q000294:innervation* / Q000378:metabolism; D008297:Male; D010121:Oxytocin / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012077:Renal Artery / Q000187:drug effects / Q000378:metabolism; D012083:Renin / Q000097:blood / Q000378:metabolism*; D013874:Thiopental / Q000031:analogs & derivatives* / Q000494:pharmacology
D000777:Anesthetics; C004316:thiobutabarbital; D010121:Oxytocin; D012083:Renin; D013874:Thiopental