Effect of pregnancy on glucose metabolism in glucose intolerant 'BB' Wistar rats.
Little is known about the effect of pregnancy on the 'BB' Wistar rat, an animal model of insulin-dependent (type I) diabetes. The pathogenesis of diabetes in this animal model seems to result from antibody-mediated natural killer cell destruction of pancreatic beta cells. The glucose metabolism of glucose intolerant female rats (study group) was studied prior to pregnancy, during pregnancy, and postpartum using glucose tolerance tests (GTT). Control rats with normal GTT were studied and bred in a fashion similar to the study animals. Before becoming pregnant, the GTT levels of the chemically diabetic rats were significantly different from those of the controls (p less than 0.05). The GTT values of the study animals decreased during pregnancy to levels seen in pregnant controls. After pregnancy, the GTT values of the study animals returned to prepregnant levels. Based on these observations, it appears that pregnancy may block the autoimmune destruction of beta cells, causing an increase in insulin production and release, thereby improving glucose metabolism.