EFFECT OF SODIUM ORTHO-VANADATE ON RENAL RENIN SECRETION INVIVO

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  • 1 January 1982
    • journal article
    • research article
    • Vol. 222  (2) , 447-451
Abstract
The effect of vanadate (0.5 .mu.mol/min) on renin secretory rate (RSR) of the kidney was studied in nembutal-anesthetized, volume-expanded dogs. Intrarenal vanadate infusion caused a 69.3 .+-. 8.8% decrease in RSR. This was accompanied by marked decreases in renal blood flow (RBF), glomerular filtration rate (GFR) and fractional excretion of sodium (FENa). Renal vascular resistance rose from 1.3 .+-. 0.09 to 6.1 .+-. 2.3 mm Hg/ml per min (P < 0.0005). Papaverine infusion partially blunted the effect of vanadate on RSR (RSR only fell to 42.0 .+-. 10% of basal values). The decreases in RBF and GFR were also less and FENa slightly higher than normal. Acetylcholine prevented the effects of vanadate more fully. There was no fall in RBF, GFR or FENa and it basically abolished the fall in RSR which fell only 19.4 .+-. 25.3 of control (P = N.S.). Nifedipine (a slow Ca2+ channels blocker) also prevented the fall in RBF, GFR and FENa induced by vanadate. RSR did not change significantly (7.8 .+-. 10.9%). Results clearly demonstrate that vanadate is a potent inhibitor of renin secretion and suggest that inhibition of smooth muscle Na+, K+, ATP and changes in the cystosolic concentration of Na and Ca are involved in its mechanism. Changes in perfusion pressure and Na delivery to the macula densa appear to have little if any role in the inhibition.