Aims/hypothesis  

Streptozotocin is a monofunctional alkylating agent that induces diabetes in a large variety of mammals. While multiple low doses of streptozotocin induce immune-mediated diabetes, a single high dose of streptozotocin causes a strictly toxic diabetes. Among mouse strains, non-obese diabetic (NOD) mice are characterized by an extreme susceptibility to high dose of streptozotocin-induced diabetes whereas C3H/Or mice are particularly resistant. We hypothesized that NOD genes involved in high dose streptozotocin-induced diabetes could be also involved in the autoimmune destruction of pancreatic beta cells that characterizes this mouse strain which is a model of Type 1 diabetes.

Methods  

We carried out a whole genome linkage scan on a population of (C3H/Or × NOD) × NOD backcross 1 mice in order to identify the genetic loci involved in NOD susceptibility to high dose of streptozotocin-induced diabetes.

Results  

Two loci, in chromosome 9 (D9Mit135 marker, 48 cM) and in chromosome 11 (D11Mit286 marker, 52 cM), were associated with NOD susceptibility to high dose streptozotocin-induced diabetes, the latter being co-localized with the autoimmune diabetes-predisposing idd4 locus. Moreover, we report here that C57BL/6 mice deficient in Nitric Oxide Synthase 2 were as sensitive as wild-type C57BL/6 mice to high dose streptozotocin-induced diabetes.

Conclusion/interpretation  

Although the Nitric Oxide Synthase 2 (Nos2) gene, localized at 45.6 cM in chromosome 11, is a good candidate gene, our results suggest that Nitric Oxide Synthase 2 activation might not be a crucial event for streptozotocin-induced destruction of pancreatic beta cells.