UNILATERAL RENAL ADRENERGIC BLOCKADE AND THE RENAL RESPONSE TO VASOPRESSOR AGENTS AND TO HEMORRHAGE

¹ Department of Pharmacology, Baylor University College of Medicine, Houston, Texas

The injection of Dibenzyline ((0.5-2 mgm.) into the renal artery produces adrenergic blockade in the injected kidney without affecting systemic blood pressure. Intravenous infusion of l-epinephrine or l-norepinephrine causes a marked reduction of renal functions in the untreated kidney. A prominent increase in urine flow, a slight increase in GFR, and no significant change in renal plasma flow are the usual effects noted in the kidney under adrenergic blockade during the infusion of vasopressor agents. Lowering the blood pressure to about 60 mm. Hg by hemorrhage depresses renal function in both kidneys but usually to a greater extent in the unblocked kidney. No evidence was encountered in any of the experiments to suggest a tonic effect of the sympathetic nervous system on the renal blood supply. These experiments indicate that sodium and water excretion are altered by changes in renal hemodynamics but not by any direct effect of the sympathetic nervous system on renal tubules.