Abstract:

 Objective   To investigate the effects of early intensive insulin therapy on insulitis, apoptosis and regeneration of islets. Methods   Twelve newly diagnosed diabetic female NOD mice were randomized into 2 groups： early intensive insulin therapy group(A, n=6)and PBS group(B, n=6), The treatments of these two groups were initiated within 3 days after the onset of diabetes. Also a PBS control group (C, n=6) of age matched nondiabetic mice was included in the study. Group B was sacrificed on the 20th day while the other two groups were killed after 60 days of treatment. Pancreases were removed to examine the insulitis scores by HE straining, and the expressions of Bcl-2 and Bax on islet cells were detected by immunohistochemical straining. Results   Diabetic symptoms disappeared after early intensive insulin therapy. The insulitis score of group A was significantly lower than that of group B (P=0.01<0.05), and there was no significant difference when compared with group C (P>0.05). The Bax expression was stronger in intensive insulin therapy group than in group C (P<0.05), but there was no significant difference when compared with group B(P=0.25). The expression of Bcl-2 on islet cells was stronger in intensive insulin therapy group than in the other two groups(P<0.05). Conclusions   Early intensive insulin therapy can decrease insulitis of Langerhans and attenuate the beta cell apoptosis.

Key words: Diabetes； Insulin； NOD Mice； Insulitis； Bax protein； Bcl-2 protein