Interleukin-1 induces time-dependent potentiation in isolated rat islets: possible involvement of phosphoinositide hydrolysis.
Prior exposure of isolated perfused rat islets to the monokine interleukin-1 (IL-1) amplifies their subsequent insulin secretory response to 10 mM glucose. This potentiating effect of the monokine is dose dependent, lasts for at least 45 min after IL-1 removal from the medium, and is not confined to glucose; IL-1 also potentiates the insulin secretory responses to tolbutamide and glyceraldehyde. IL-1 exposure of islets incubated with myo-[2-3H]inositol to label their phosphoinositides (PI) results in an increase in [3H]inositol efflux, an event that persists long after removal of IL-1 from the medium. Direct measurements of labeled inositol phosphate accumulation substantiate the concept that this sustained [3H]inositol efflux response is the direct result of a sustained increase in PI hydrolysis. These results expand the list of compounds that induce time-dependent potentiation in islets to include IL-1. This action of the monokine, mediated at least in part by PI-derived second messenger molecules, may contribute to its postulated effects on insulin and glucose homeostasis.
Zawalich
W S
WS
Yale University School of Nursing, New Haven, Connecticut 06536-0740.
Dierolf
B
B
Zawalich
K C
KC
D000818:Animals; D006868:Hydrolysis; D066298:In Vitro Techniques; D007295:Inositol Phosphates / Q000378:metabolism; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007375:Interleukin-1 / Q000494:pharmacology*; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D010716:Phosphatidylinositols / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D013997:Time Factors
D007295:Inositol Phosphates; D007328:Insulin; D007375:Interleukin-1; D010716:Phosphatidylinositols