Transgenic mice expressing ifn-[gamma] in the pancreatic beta cells are resistant to streptozotocin-induced diabetes. Gu, Danling, Marc Arnush, Stephen P. Sawyer, and Nora Sarvetnick. Department of Neurophamacology CVN-10, The Scripps Research Institute, La Jolla, California 92037
APStracts 2:0144E, 1995.
Gu, Danling, Marc Arnush, Stephen P. Sawyer, and Nora Sarvetnick. In 28 adult Ins-IFN-[gamma] transgenic mice, injection of high doses of streptozotocin (STZ-first injection, 300 [mu]g/g body weight; second injection, 200 [mu]g/g body weight 4 hr later) failed to induce severe hyperglycemia. To the contrary, 28 BALB/c mice developed diabetes mellitus after identical injections of STZ. Because the STZ -induced islet damage was partially inhibited in Ins-IFN-[gamma] transgenic mice, their glycemia levels became normal 4 days after STZ administration. Both transgenic and BALB/c mice lost weight after receiving STZ, but the body weights of transgenic mice then returned to pre-treatment levels in a nearly parallel manner with the glycemia. Immunolabeling with insulin, identified an unusual spreading pattern of insulin immunoreactivity. Ultrastructural observations confirmed that [beta] cell necrosis and degranulation were more severe in STZ-treated BALB/c than in Ins-IFN-[gamma] transgenic mice. Moreover, regeneration of pancreatic duct cells and islet neogenesis were observed in the transgenic mice. Therefore, after STZ treatment, the Ins-IFN-[gamma] transgenic mice apparently were resistant to the induction of severe diabetes, whereas their BALB/c age-matched counterparts succumbed to the disease.

Received 24 May 1995; accepted in final form 29 June 1995.
APS Manuscript Number E232-5.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 18 July 1995.