Dietary calcium and development of hypertension in spontaneously hypertensive rats

The purpose of the present study was to attempt to correlate four calcium diets (0.02, 0.1, 0.5 and 2.5%) with changes in the development of hypertension in both spontaneously hypertensive and Wistar-Kyoto rats. Our findings confirm that an inverse relationship exists between dietary calcium content and the development of hypertension. The relationship does not rely upon altered serum ionized sodium, potassium, or calcium or parathyroid hormone levels. In addition, no consistent dietary calcium-dependent changes were noticed in cardiovascular reactivity. In contrast, anesthesia with pentobarbital completely abolished the relationship. These data support the hypothesis that dietary calcium influences autonomic tone through some, as yet, undefined processes.