Glucagon-like peptide-1 stimulates insulin secretion but not phosphoinositide hydrolysis from islets desensitized by prior exposure to high glucose or the muscarinic agonist carbachol

Metabolism: Clinical and Experimental
Walter S Zawalich, Kathleen C Zawalich

Abstract

In the present series of experiments, the ability of the postulated incretin factor, glucagon-like peptide-1 (GLP-1), to stimulate insulin release from desensitized islets was determined. Compared with responses observed from control islets incubated for 3.5 hours with 5.6 mmol/L glucose alone, prior exposure to 10 mmol/L glucose, 20 mmol/L glucose, or 10 micromol/L carbachol reduced peak second-phase insulin release rates to a subsequent 20-mmol/L glucose stimulus by 63%, 81%, or 70%, respectively. Efflux of 3H-inositol from prior high-glucose- or carbachol-exposed islets was abolished and accumulation of inositol phosphates (IPs) in response to 20 mmol/L glucose was reduced. Further addition of 10 nmol/L GLP-1 together with 20 mmol/L glucose significantly increased insulin output from desensitized islets. Carbachol (10 micromol/L) preexposure also abolished the subsequent insulin secretory and 3H-inositol efflux responses to 8 mmol/L glucose plus 10 micromol/L carbachol. Inclusion of 10 nmol/L GLP-1 together with 8 mmol/L glucose plus 10 micromol/L carbachol improved but did not normalize secretion from these islets. These improvements in secretory responsiveness from high-glucose- or carbachol- desensitized islets occurred d...Continue Reading

References

Jan 1, 1992·Journal of Cellular Biochemistry·G M Grodsky, J L Bolaffi
Apr 17, 1990·Molecular and Cellular Endocrinology·W S Zawalich, H Rasmussen
Jun 1, 1990·Diabetes Care·H RasmussenW S Zawalich
Oct 1, 1987·Physiological Reviews·M Prentki, F M Matschinsky
May 1, 1987·Proceedings of the National Academy of Sciences of the United States of America·D J DruckerJ F Habener
Jan 1, 1987·Diabetes/metabolism Reviews·R Ebert, W Creutzfeldt
Jan 1, 1982·The Journal of Membrane Biology·A B BorleJ H Anderson
Aug 1, 1995·Diabetologia·W S Zawalich, G G Kelley

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Citations

May 10, 2005·The British Journal of Nutrition·Rémy Burcelin
Dec 12, 2002·Diabetes·Patrick E MacDonaldMichael B Wheeler
Aug 18, 2005·American Journal of Physiology. Endocrinology and Metabolism·Hanae YamazakiWalter S Zawalich

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