Effect of a selective octapeptide analogue of somatostatin on renal water excretion in the dog.

Somatostatin produces a modest water diuresis in dogs by inhibiting the renal tubular action of ADH. SMS 201-995, an octapeptide analogue of somatostatin, is more potent and longer-acting than the native hormone, and possesses greater specificity in the inhibition of growth hormone secretion. In the present study we tested the ability of the analogue to produce urinary dilution following infusion (0.12 to 0.50 micrograms/min) into the left renal artery. Infusion in this dose range increased urine flow from 0.20 to 0.55 mL/min (P less than 0.05) and caused a 49% to 56% reduction in urine osmolarity. We conclude that SMS 201-995 is effective in causing a water diuresis in dogs and at smaller doses than required for the native hormone.