Abstract

BACKGROUND
IL-1beta has been implicated to play an important role in the autoimmune beta cell lesion of type 1 diabetes because of its inhibition of insulin secretion and direct islet cytotoxicity. Thus, this study evaluated the effect of aminoguanidine on No production, insulin release and hsp 70 expression in cultured rat islets exposed to IL-1beta. METHOD: Islets isolated from Sprague-Dawley rats were cultured with IL-1beta , aminoguanidine AG and GSNO, individually and in combination for 24hours. Accumulated nitrite production, insulin release and islet expression of hsp 70 were measured. RESULTS: IL-1beta increased nitrite production, inhibited insulin release, and increased hsp 70 expression. AG alone had no effect on nitrite production, insulin release and hsp 70 expression. In combination, AG completely blocked IL-1beta but increased nitrite production, reversed IL-1beta inhibited insulin release and reversed IL-1beta increased hsp 70 expression. Moreover, nitric oxide NO donor, GSNO stimulated hsp 70 expression. CONCLUSION: Findings from this study suggest that hsp 70 may be one potential protein that is expressed in response to NO and that participates in islet recovery from NO mediated islet damage.

• Keywords: Interleukin-1;Rat Islets;Heat Shock Protein 70;Aminoguanidine