The response of plasma somatostatin-like immunoreactivity to nutrients in normal and alloxan diabetic dogs.

Abstract

Somatostatin-like immunoreactivity (SLI) was measured by RIA in the plasma of normal and severely alloxan diabetic dogs in the fasting state and after the administration of nutrients. The iv infusion of glucose for 6 h was associated with a small but significant decline in plasma SLI (162 ± 10 to 146 ± 9 pg/ml; P < 0.01). In nine alloxan diabetic dogs, the baseline SLI levels averaged 212 ± 16 pg/ml, significantly higher than normal (P < 0.005), and there was little or no change during glucose infusion. Intragastric glucose elicited only a small transient rise in SLI in normal dogs, while in the diabetic dogs, a significant change in SLI was not observed. Intragastric administration of casein hydrolysate to nine normal dogs was associated with a rise in plasma SLI from < 0.02). After a liver meal, SLI rose in normal dogs from 134 ± 7 to 190 ± 15 pg/ml within 30 min (P < 0.001) and in the diabetic dogs, it rose from 240 ± 20 to a 30-min level of 244 ± 33 pg/ml (P < 0.005). In normal dogs, a fat-protein mea...