Low concentrations of interleukin-1 stimulate and high concentrations inhibit insulin release from isolated rat islets of Langerhans.
Isolated rat islets were incubated either with crude, affinity-purified or recombinant human interleukin-1 for 1 to 6 days. A significant (20-60%) increase of insulin release was observed at low concentrations of all three interleukin-1-containing preparations. In contrast, higher concentrations dose-dependently inhibited the insulin release. The increased insulin secretion occurred at concentrations below those necessary to augment the mitogen response to phytohaemagglutinin of murine thymocytes in vitro. These doses (0.05-0.5 U/ml) correspond to 0.2-2 ng of recombinant interleukin-1 per ml, equal to approximately 0.01-0.1 pmol/ml. In doses of 0.6-1.8 U/ml affinity-purified interleukin-1 significantly increased the islet insulin content per ng of DNA, indicating a stimulation of insulin-biosynthesis. The data support the concept that low concentrations of interleukin-1 may play a role in priming the physiological secretion of insulin.
D000818:Animals; D002478:Cells, Cultured; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007375:Interleukin-1 / Q000008:administration & dosage*; D007515:Islets of Langerhans / Q000378:metabolism*; D051381:Rats
D007328:Insulin; D007375:Interleukin-1