Effects of Calcium and Deoxycorticosterone on Blood Pressure, Plasma Renin Activity and Vascular Reactivity in Spontaneously Hypertensive Rats

Abstract
The effects of calcium and deoxycorticosterone (DOC) on blood pressure, plasma renin activity (PRA), urinary sodium excretion and aortic responses were studied in spontaneously hypertensive rats (SHR). The animals (age 9 weeks) were divided into four treatment groups: control, calcium, DOC and DOC+calcium (n=12 and the mean systolic blood pressure 174–177 mmHg in each). Calcium was given as 1.5 % CaC12, in drinking fluid, and DOC trimethyl-acetate by weekly injections (25 mg/kg s.c.). During the 4–week study systolic blood pressure rose in all groups, but the increase was attenuated by calcium (final levels: control 201·3, calcium 186·3, DOC 206·2, DOC+calcium 203·2 mmHg, mean). PRA was reduced in both groups receiving DOC, but it was not affected by calcium.