Calcium metabolism in the Lyon hypertensive rat.

In order to define relationships between hypertension and calcium metabolism, we have studied calcium metabolism in Lyon genetically hypertensive rats (LH) and their two normotensive controls (LN and LL). The total and ionized plasma calcium levels were slightly but significantly decreased in the LH compared to LN and LL from 4 to 23 weeks of age. During this period, dietary calcium intake was decreased in LH rats but urinary and fecal excretions did not differ. Intestinal utilization and balance were impaired during development of hypertension in LH rats. Thus minor alterations in calcium metabolism differentiate the LH rat from its normotensive controls.