Importance of Calcium in the Renal Hemodynamic Changes Induced by Vanadate
Vanadate has been recognized as an inhibitor of (Na+, K+)-ATPase (1, 5). Several groups have emphasized it’s potential role as a regulator of the enzyme in the kidney (6), an organ where vanadium tends to accumulate (7). In the dog, intraarterial infusion of vanadate produces a marked vasoconstriction, a decrease in renal blood flow and glomerular filtration rate as well as a decrease in urine flow and sodium excretion (8, 9). In addition to the hemodynamic changes there is also a decrease in renin secretion (10, 11), suggesting that the vasoconstriction is a direct result of the inhibition of the vascular ATPase system. Inhibition by vanadate of sodium or calcium pumps may increase the influx of Ca++ or reduce its efflux from the cytoplasm of muscle cell. This increase in cytoplasmic Ca++ may serve as a stimulus for vasoconstriction.
KeywordsRenal Artery Serum Calcium Renal Blood Flow Urine Flow Sodium Orthovanadate
Unable to display preview. Download preview PDF.
- 6.J. J. Grantham, The renal sodium pump and vanadate. Am. J. Physic): 239: F97 (1980).Google Scholar
- 10.P. C. Churchill and M. C. Churchill, Vanadate inhibits renin secretion from rat kidney slices. J. Pharmacol. Exp. Ther. 213: 114 (1980).Google Scholar
- 12.A.Kamur and C. N. Corder, Diuretic and vasoconstrictor effects of sodium orthovanadate on the isolated perfused rat kidney. J. Pharmacol. Exp. Ther. 213: 85 (1980).Google Scholar
- 14.J. P. Rapp, Aortic responses to vanadate: independence from (Na+ and K+)-ATPase and comparison of Dahl salt-sensitive and salt-resistant rats. Hypertension 3: 1168 (1980).Google Scholar
- 22.A. Heinz, K. A. Rubinson, and J. J. Grantham, The transport and accumulation of oxyvanadium compounds in human erythrocytes in vitro. J. Lab. Clinc. Med. 100: 593 (1982).Google Scholar