cholecalciferol and Cataract

Parathyroid hormone (PTH), calcitonin (CT)and calciferol (Vit. D3) operate synchronously to maintain a balance between calcium and phosphate levels in serum. An aberration of specific steps in the homeostatic process results in hypo/hyper phosphatemia. These aberrations may eventually lead to several diseased states. PTH and Vit. D3 induced hypercalcemia can, however, be significantly inhibited by calcitonin (CT). These findings have been correlated with the levels of calcium and phosphate obtained from human senile cataractous lenses of cortical and nuclear types. The comparison of the results indicate that amongst these three hormones PTH is most vulnerable in leading towards conditions for possible cataract formation in rat lens.

Topics: Animals; Calcitonin; Calcium; Cataract; Cholecalciferol; Lens, Crystalline; Male; Parathyroid Hormone; Phosphates; Rats

Vitamin D3 in the presence of calcium lactate induced significant hypercalcemia and hyperphosphatemia while calcitonin in the presence of a chelating agent (EGTA) induced hypocalcemia and hypophosphatemia in the rat lens. The physiologic significance of these changes in relation to cataract formation was understood by correlating the ratio of calcium and phosphate in the rat lens with the similar ratio obtained from human cataractous lenses of cortical and nuclear types.

Topics: Animals; Calcitonin; Calcium; Cataract; Cholecalciferol; Egtazic Acid; Humans; Hypercalcemia; Lactates; Lactic Acid; Lens, Crystalline; Male; Phosphates; Rats