Age- and Diabetes-related Changes in Tissue Glucose Uptake and Estradiol Accumulation in the C57BL/KsJ Mouse

The effect of the diabetes (db/db) mutation on the agerelated changes in glucose uptake and estradiol incorporation in peripheral tissues were investigated in C57BL/KsJ mice between 2 and 16 wk of age. Glucose uptake in the uterus, ovaries, pancreas, lung, liver, heart, kidney, and spleen were markedly increased in diabetic mice after the development of the hyperglycemic condition, as compared with control mice. The age-related increase in glucose uptake observed in control mice was enhanced in hyperglycemic (i.e., ≥4 wk of age) animals. In contrast, the diabetes mutation caused a decreased estradiol uptake by the uteri, ovaries, and mesometrial fat pads at 16 wk, while having little effect in nontarget tissues of diabetic mutants. These data indicate that the diabetes mutation enhances glucose uptake, especially in estradiol target tissues (i.e., uterus, ovary), at the same time that estradiol incorporation is depressed. These results suggest that an alteration in glucose utilization by steroid-sensitive reproductive tract tissue may underlie the impaired reproductive ability in these animals. Other peripheral tissues did not demonstrate any remarkable changes in estradiol uptake, but the enhanced carbohydrate metabolism observed may relate to the subsequent age- and diabetes-related changes in tissue structure and function in these animals.