DIRECT RENOVASCULAR EFFECT OF SOMATOSTATIN IN THE DOG

Recently, effects of somatostatin on the renal function have been desc ribed and the vasoactive properties of the peptide were proposed to co ntribute to this action. However, the available data on its effect in the renal vascular bed are very controversial. Therefore, we investiga ted the effect of local intraarterial somatostatin boluses in a wide r ange of doses (5 X 10(-11)-5 X 10(-5) g) on the renal blood flow (RBF) in anesthetized dogs. RBF was measured by an electromagnetic flow pro be. Somatostatin did not influence blood pressure or heart rate. RBF e xhibited a significant, dose-dependent fall (ranging from 11.6 +/- 11. 9% to 31.9 +/- 17.3%), with a threshold at a dose of 5 x 10(-10) g. Th ese results offer conclusive evidence for the contribution of somatost atin-induced direct renal vasoconstriction to its renal effects, in ad dition to the demonstrated modulation of other vasoactive systems and tubular functions.