Cysteine analogues potentiate glucose-induced insulin release in vitro
In rat pancreatic islets, cysteine analogues, including glutathione, acetylcysteine, cysteamine, D-penicillamine, L-cysteine ethyl ester, and cysteine-potentiated glucose (11.1 mM) induced insulin secretion in a concentration-dependent manner. Their maximal effects were similar and occurred at approximately 0.05, 0.05, 0.1, 0.5, 1.0, 1.0 mM, respectively. At substimulatory glucose levels (2.8 mM), insulin release was not affected by these compounds. In contrast, thiol compounds, structurally different from cysteine and its analogues, such as mesna, tiopronin, meso-2,3-dimercaptosuccinic acid (DMSA), dimercaprol (BAL), beta-thio-D-glucose, as well as those cysteine analogues that lack a free-thiol group, including L-cystine, cystamine, D-penicillamine disulfide, S-carbocysteine, and S-carbamoyl-L-cysteine, did not enhance insulin release at stimulatory glucose levels (11.1 mM); cystine (5 mM) was inhibitory. These in vitro data indicate that among the thiols tested here, only cysteine and its analogues potentiate glucose-induced insulin secretion, whereas thiols that are structurally not related to cysteine do not. This suggests that a cysteine moiety in the molecule is necessary for the insulinotropic effect. For their synergistic action to glucose, the availability of a sulfhydryl group is also a prerequisite. The maximal synergistic action is similar for all cysteine analogues tested, whereas the potency of action is different, suggesting similarity in the mechanism of action but differences in the affinity to the secretory system.
- Research Organization:
- Univ. of Tuebingen, Germany, F.R.
- OSTI ID:
- 6962575
- Journal Information:
- Diabetes; (United States), Journal Name: Diabetes; (United States) Vol. 12; ISSN DIAEA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Reduction of the secretory response to Escherichia coli heat-stable enterotoxin by thiol and disulfide compounds. [Mice]
Glucose activates prenyltransferases in pancreatic islet {beta}-cells
Related Subjects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALDEHYDES
AMINES
AMINO ACIDS
ANIMALS
BIOLOGICAL EFFECTS
CARBOHYDRATES
CARBOXYLIC ACIDS
CHELATING AGENTS
CYSTEINE
DRUGS
GLUCOSE
GLUTATHIONE
HEXOSES
HORMONES
INSULIN
MAMMALS
MEA
MONOSACCHARIDES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PENICILLAMINE
PEPTIDE HORMONES
PEPTIDES
POLYPEPTIDES
PROTEINS
RADIOPROTECTIVE SUBSTANCES
RATS
RODENTS
SACCHARIDES
SECRETION
THIOLS
VERTEBRATES