Vanadate-induced oliguria and vasoconstriction in the cat.

The effect of sodium orthovanadate (vanadate) on kidney function and hemodynamics was tested in chloralose anesthetized, fasting cats. Vanadate given i.v. caused a reversible, marked decrease in glomerular filtration rate and urine production without significantly affecting the fractional water excretion rate. In the recovery period, after administration of vanadate, urine flow and the urinary excretion rate of electrolytes were only slightly different from control values. This action of vanadate appears to be due mainly to constriction of the renal blood vessels leading to a fall in glomerular capillary pressure. Vanadate likewise caused a dose dependent decrease in arterial conductance and blood flow of other vessels in the splanchnic area, whereas the femoral and carotid arteries were reversely and less affected. The vascular effect appears to be caused by a direct action of vanadate on vascular smooth muscle, but the mechanism of action is still unsettled.