Pharmacological evidence that the sympathetic nervous system mediates the increase in renin secretion produced by immobilization and head-up tilt in rats.
To determine the mechanism by which immobilization and head-up tilt under inactin anesthesia increase plasma renin activity (PRA), the effect of these stimuli on plasma levels of vasoactive intestinal polypeptide (VIP) were measured and the effect of the beta-adrenergic blocking drug, propranolol on the response of plasma renin activity determined. Increases in circulating VIP are known to stimulate secretion of renin. After 10 min of immobilization, plasma renin activity was increased and VIP in plasma was unchanged. After 30 min of tilting, plasma renin activity was also increased and VIP in plasma was unchanged. The increases in plasma renin activity were blocked by propranolol. Inactin anesthesia by itself increased plasma renin activity and this response was unaffected by propranolol and associated with a small decrease, rather than an increase in VIP in plasma. The results indicate that the responses of plasma renin activity to immobilization and head-up tilt are due to increased secretion of renin mediated by the sympathetic nervous system. On the other hand, the increase in secretion of renin produced by inactin anesthesia does not appear to be mediated by the sympathetic nervous system. There was no evidence that VIP was responsible for any of the increases.
Golin
R M
RM
Department of Physiology, University of California, San Francisco 94143.
Gotoh
E
E
Said
S I
SI
Ganong
W F
WF
D000818:Animals; D007103:Immobilization; D007262:Infusions, Intravenous; D007274:Injections, Intraperitoneal; D008297:Male; D009949:Orientation / Q000502:physiology*; D011433:Propranolol / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012083:Renin / Q000097:blood*; D013564:Sympathetic Nervous System / Q000502:physiology*; D013874:Thiopental / Q000031:analogs & derivatives; D014660:Vasoactive Intestinal Peptide / Q000097:blood*
C004316:thiobutabarbital; D014660:Vasoactive Intestinal Peptide; D011433:Propranolol; D012083:Renin; D013874:Thiopental