Insulin release. Demonstration of a priming effect of 3-isobutyl-1-methyl-xanthine (IBMX) on islets of Langerhans.
Exposure of isolated rat pancreatic islets to 1 mM 3-isobutyl-1-methyl-xanthine (IBMX) resulted in a 5.7-fold increase in the rate of insulin release. After a 30-min rest period under basal conditions, reexposure of the islets to 1 mM IBMX resulted in an enhanced rate of release when compared with either a timed control -islets simultaneously exposed to IBMX for the first time-or with the first priming response to IBMX. The possibility of a continuous priming effect was suggested by the gradually rising rate of insulin release during exposure to IBMX. It is concluded that islets have a memory for IBMX exposure that results in increased responsiveness to subsequent stimulation by IBMX.
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology*; D000818:Animals; D005947:Glucose / Q000494:pharmacology; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013806:Theophylline / Q000031:analogs & derivatives*
D007328:Insulin; D013806:Theophylline; D005947:Glucose; D015056:1-Methyl-3-isobutylxanthine