Effects of dietary calcium on the development of salt hypertension in young and adult Dahl rats.

Abstract

The effect of dietary calcium on the development of salt hypertension was studied in young and adult Dahl rats. Age-dependent development of blood pressure was compared in salt-sensitive (DS) and salt-resistant (DR) Dahl rats that were fed either a low-calcium (0.15%) or a high-calcium (2.5%) diet. Systolic blood pressure was consistently higher in DS rats than in a comparable group of DR rats. In young DS rats the high-calcium diet transiently attenuated the development of hypertension, whereas in adult rats this diet potentiated the development of hypertension. In young DS rats total plasma calcium was increased by the high-calcium diet, but in adult rats it was significantly decreased. Our results suggest that the effects of dietary calcium supplementation on calcium metabolism and the development of salt hypertension in DS rats depend on the age at which calcium supplementation is started.