Influence of somatostatin on plasma cyclic AMP and metabolic substrate responses to i.v. adrenaline and glucagon in humans.
The influence of somatostatin (a bolus injection of 250 micrograms i.v. followed by 6 micrograms/min for 40 min) on the plasma cyclic AMP, insulin, glucose and non-esterified fatty acid (NEFA) responses to i.v. adrenaline (0.07 micrograms/kg body-weight/min for 20 min) and the plasma cyclic AMP, insulin and glucose responses to a bolus injection of i.v. glucagon (0.01 mg/kg BW) were studied in normal subjects. Somatostatin suppressed the insulin response to glucagon and inhibited the insulin rebound observed on termination of adrenaline infusion. The plasma glucose response to glucagon was exaggerated by somatostatin, reflecting insulin deficiency. Neither the plasma glucose or plasma non-esterified fatty acid responses to adrenaline were influenced by somatostatin. Adrenaline produced a three-fold and glucagon a twenty-fold rise in plasma cyclic AMP and 15 min. This was not influenced by concurrent somatostatin infusion, indicating that somatostatin is not a universal inhibitor of hormone stimulated adenylate cyclase activity. This is supported by the failure of somatostatin to inhibit the metabolic actions of glucagon and adrenaline thought to be mediated by cyclic AMP.
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D000242:Cyclic AMP / Q000097:blood*; D004837:Epinephrine / Q000494:pharmacology*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D005934:Glucagon / Q000494:pharmacology*; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D013004:Somatostatin / Q000494:pharmacology*
D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D013004:Somatostatin; D005934:Glucagon; D000242:Cyclic AMP; D004837:Epinephrine