[Regulation of calcium metabolism in hypertension]

In patients with hypertensive disease, the intravenous calcium tolerance test revealed a delayed elimination of loading hypercalcemia, which totally reflects the effectiveness mechanisms aimed at removing excessive calcium from the extracellular space. In hypertensives, renal calcium excretion was also delayed due to a lower suppression of calcium channel reabsorption. The patients showed a greater background concentration of parathyroid hormone (PTH) and during the calcium tolerance test a much lower PTH levels and higher calcitonin concentrations, though their homeostatic effects remained inadequate due to their diminished sensitivity of target organs. Thus, there was an increase in the activity of parathyroidal glands in patients with hypertensive disease.