Insulin release by glucagon and secretin : studies with secretin-glucagon hybrids
Summary, in English
Secretin and glucagon potentiate glucose-induced insulin release. We have compared the effects of secretin and glucagon with that of four hybrid molecules of the two hormones on insulin release and formation of cyclic AMP (cAMP) in isolated mouse pancreatic islets. All six peptides potentiated the release of insulin at 10mM D-glucose, and their effects were indistinguishable with respect to the dynamics of release, dose-response relationship, and glucose dependency. However, measurements of cAMP accumulation in the presence of the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (10-4M) showed that the fold increase compared with glucose alone had the following ranking order: secretin = [Tyr10, Tyr13]-secretin 1.6<[Tyr10, Tyr13, Trp25]secretin 1.8<glucagon 1.9<[Asp3, Glu9, Arg12]glucagon 2.3 = [Asp3, Glu9]glucagon. These results suggest that despite similar potentiating effects of secretin and glucagon on glucose-induced insulin release, their modes of action may be different.
American Journal of Physiology - Endocrinology and Metabolism
American Physiological Society
- ISSN: 0193-1849