Electrophysiological evidence for the autoregulation of beta-cell secretion by insulin.
Electrophysiological studies of cultured rat pancreatic beta-cells using intracellular microelectrodes show that exogenous insulin over the range of 0.1 -- 10.0 microng/ml inhibits the electrical activity due to 27.8 mM glucose in a dose-related manner. This inhibitory effect is manifested by a mean increase of the membrane potential from about --20 to --30 mV and inhibition of the number of cells impaled showing spike activity from 60 to less than 10%. The inhibitory influence of insulin is rapid occurring within 5 min for the highest level used. The results provide evidence for a negative feedback role of insulin in regulating its own release.
D000818:Animals; D002478:Cells, Cultured; D004553:Electric Conductivity; D005947:Glucose / Q000494:pharmacology; D007328:Insulin / Q000378:metabolism* / Q000494:pharmacology; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D008297:Male; D051381:Rats
D007328:Insulin; D005947:Glucose