Non-selective inhibition of basal glucagon release by [D-Cys14]-analogues of somatostatin in the rat.
The effects of two [D-Cys14]-analogues of somatostatin on basal plasma levels of glucagon, insulin and glucose were determined in unanaesthetized rats to re-examine a glucagon-selective action of these peptides which has been claimed by others. Somatostatin, [D-Cys14]-somatostatin and [D-Trp8, D-Cys14]-somatostatin caused a short-lasting, dose-dependent decrease of plasma glucagon and insulin but they had no significant influence on plasma glucose. Glucagon and insulin reached the nadir 2 min after intravenous injection of the peptides (dose range 1--10 micrograms/kg) or 5 min after subcutaneous administration (30 and 300 micrograms/kg). At the nadir, insulin was decreased to a greater extent than glucagon and the effecer the nadir and at high doses, the time-course of some effects of the analogues on either glucagon or insulin differed from that of somatostatin. Thus, these [D-Cys14]-analogues may show partial kinetic dissociation of effects on glucagon and insulin but they are not truly selective inhibitors of glucagon release.
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D005934:Glucagon / Q000097:blood / Q000378:metabolism*; D007275:Injections, Intravenous; D007279:Injections, Subcutaneous; D007328:Insulin / Q000097:blood / Q000378:metabolism; D000078790:Insulin Secretion; D008297:Male; D051381:Rats; D012636:Secretory Rate / Q000187:drug effects; D013004:Somatostatin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology
D001786:Blood Glucose; D007328:Insulin; D013004:Somatostatin; D005934:Glucagon