A possible role of plasma glutathione in glucose-mediated insulin secretion: in vitro and in vivo studies in rats.
In isolated rat pancreatic islets exogenous glutathione which is not able to penetrate into cells, augmented glucose (11.1 mmol/l)-mediated insulin release. In the presence of a non-stimulatory glucose concentration (2.8 mmol/l) glutathione had no effect. The half-maximal synergistic action of glutathione on insulin secretion was observed at approximately 8.0 mumol/l. This concentration of glutathione is similar to that found in the plasma of non-fasted anaesthetised rats (6.5 mumol/l). Oral ingestion of glucose increased the arterial plasma glutathione in rats. Our data provide for the first time indirect evidence for a modulating effect of plasma glutathione in postprandial glucose-mediated insulin secretion which appears to be located at the extracellular site of islet cells.
Ammon
H P
HP
Department of Pharmacology, University of Tübingen, FRG.
Klumpp
S
S
Fuss
A
A
Verspohl
E J
EJ
Jaeschke
H
H
Wendel
A
A
Müller
P
P
D000818:Animals; D001692:Biological Transport; D001786:Blood Glucose / Q000378:metabolism; D005260:Female; D005947:Glucose / Q000494:pharmacology*; D005978:Glutathione / Q000031:analogs & derivatives / Q000097:blood* / Q000378:metabolism / Q000494:pharmacology; D019803:Glutathione Disulfide; D066298:In Vitro Techniques; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013395:Sucrose / Q000378:metabolism
D001786:Blood Glucose; D007328:Insulin; D013395:Sucrose; D005978:Glutathione; D005947:Glucose; D019803:Glutathione Disulfide