Effects of neuropeptide Y on intrarenal hemodynamics, plasma renin activity and urinary sodium excretion in rats.
Neuropeptide Y (NPY) is a vasoconstrictor peptide possibly involved in the regulation of renal sodium handling and renin release. This investigation was undertaken to assess in conscious normotensive rats the acute effects of a non-pressor dose of NPY on renal plasma flow, glomerular filtration rate, sodium excretion and plasma renin activity. Experiments were also performed during concomitant beta-adrenoceptor stimulation with isoproterenol. NPY per se had no effect on the studied parameters. Renal plasma flow was increased by isoproterenol and was significantly higher when the beta-adrenoceptor stimulant was infused alone (13.4 +/- 2.1 ml/min, p < 0.05, mean +/- SEM) that when administered together with NPY (7.2 +/- 2.0 ml/min). This was also true for glomerular filtration rate (3.3 +/- 0.3 vs. 1.8 +/- 0.3 ml/min, p < 0.01) and plasma renin activity (6.3 +/- 1.7 vs. 2.1 +/- 0.4 ng Ang I/ml/h, p < 0.05). Our data however do not allow to deduce whether the inhibitory effect of NPY on isoproterenol-induced renin release is mediated by changes in intrarenal hemodynamics or a direct effect on juxtaglomerular cells.
Evéquoz
D
D
Division of Hypertension, University of Lausanne, Switzerland.
Aubert
J F
JF
Nussberger
J
J
Biollaz
J
J
Diezi
J
J
Brunner
H R
HR
Waeber
B
B
D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D005919:Glomerular Filtration Rate / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D007262:Infusions, Intravenous; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D009478:Neuropeptide Y / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012079:Renal Circulation / Q000187:drug effects*; D017595:Renal Plasma Flow / Q000187:drug effects; D012083:Renin / Q000097:blood*; D012084:Renin-Angiotensin System / Q000187:drug effects; D012964:Sodium / Q000652:urine*
D000318:Adrenergic beta-Agonists; D009478:Neuropeptide Y; D012964:Sodium; D012083:Renin; D007545:Isoproterenol