Bone maturation and resorption by peritoneal macrophages in noninsulin-dependent streptozocin-induced diabetes in the rat.

The existence of osteopenia in noninsulin-dependent diabetes mellitus (NIDDM) is controversial. In this regard rats with a diabetic condition that simulates NIDDM have normal bone mineral content. However, normal total mineral content in bones does not preclude abnormalities in more delicate functions in bones of rats with NIDDM (specifically, bone maturation and response of bone matrix to resorptive activity). To evaluate these functions, bone maturation was studied in tibias from 14-week old male and female rats with streptozocin-induced NIDDM and controls. The ability of macrophages to resorb bone was studied in bone particles that were obtained from femors of male rats with NIDDM and controls. The diabetic rats had the overt NIDDM condition for 8 weeks at the time of the study. We found that bone maturation/mineralization remained intact in the diabetic rats and that response of the bone particles that were obtained from their femors to the resorptive activity of macrophages was similar to that of the bone particles that were obtained from controls. These data suggest that in the rat, a diabetic condition that simulates NIDDM does not alter the physiologic functions of the bone matrix.