The low dose streptozotocin murine model of type 1 (insulin-dependent) diabetes mellitus: studies in vivo and in vitro of the modulating effect of sex hormones.

The influence of sex on pancreatic islet B cell susceptibility to streptozotocin was studied in mice given multiple low doses of streptozotocin. Male C3 D2 F1 mice developed a steadily increasing blood glucose level after a lag period of about 3 weeks, in contrast to females who were resistant. Spleen cells from streptozotocin treated female animals produced hyperglycaemia in total body irradiated syngeneic female recipients, but only if the recipients were treated with testosterone. Testosterone treatment of donors did not affect blood glucose levels of recipients. Streptozotocin cytotoxicity in vitro determined by a 51Cr-release assay revealed an increased sensitivity to streptozotocin in dispersed islet cells from adult male animals as compared with cells from adult female mice. The incubation of islet cells from animals of either sex with testosterone, or oestradiol plus progesterone, did not enhance the susceptibility to streptozotocin. Islet cells from sexually immature male or female mice were less susceptible to streptozotocin. The results demonstrate that sex determines susceptibility to streptozotocin in vivo and in vitro.