Endocrine regulation of calcium and phosphate in rat eye lens and its significance in cataract formation.

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.