title: The role of thymic immunity and insulitis in the development of streptozocin-induced diabetes in mice.
abstract: This article is concerned with the role of thymic immunity in the development of diabetes experimentally induced by multiple injections of subdiabetogenic doses of streptozocin (STZ). Euthymic +/+, +/nu, and athymic nu/nu mice of CD-1 and BALB/cAJcl origin were studied. Daily intraperitoneal (i.p.) injections of 30 mg/kg body wt of STZ for 5 consecutive days in CD-1 +/+ and +/nu mice resulted in hyperglycemia and mononuclear cell infiltrations of islets (insulitis). The CD-1 nu/nu mice developed neither insulitis nor hyperglycemia after the same treatment. In the nu/nu mice, when thymic immunity was restored by thymus grafting, both insulitis and hyperglycemia developed, thus demonstrating that thymic immunity was a prerequisite for the development of insulitis and hyperglycemia. There was a positive correlation among the degrees of thymic immunity, insulitis, and hyperglycemia in CD-1 +/nu, nu/nu with thymus grafts, and nu/nu mice, indicating that thymic immunity may amplify the diabetogenic effect of STZ by eliciting insulitis. In contrast, in BALB/cAJcl mice, a nonsusceptible strain to insulitis, no significant differences in plasma glucose levels were observed between the +/nu and nu/nu or between the nu/nu and thymus-grafted nu/nu mice. Furthermore, no significant difference was found in plasma testosterone levels between the +/nu and nu/nu mice of both CD-1 and BALB/cAJcl origin. In conclusion, our data indicate that thymic immunity enhances the diabetogenic effect of STZ by eliciting insulitis in susceptible mice.
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000276:immunology* / Q000473:pathology; D007111:Immunity, Cellular; D007515:Islets of Langerhans / Q000473:pathology*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008819:Mice, Nude; D013045:Species Specificity; D013311:Streptozocin / Q000633:toxicity; D013601:T-Lymphocytes / Q000276:immunology; D013739:Testosterone / Q000097:blood; D013950:Thymus Gland / Q000276:immunology* / Q000637:transplantation
chemical_list: D001786:Blood Glucose; D013739:Testosterone; D013311:Streptozocin