title: Calcium supplementation in salt-dependent hypertension.
abstract: To clarify the mechanism of the antihypertensive effect of oral Ca loading, we studied the effect of Ca supplementation on salt-induced blood pressure elevations in patients with essential hypertension and DOCA-salt hypertensive rats. When the diet was changed from low to high salt (300 mEq/day), the percent increase in mean blood pressure was smaller (p less than 0.01) in the Ca-supplemented (2,160 mg/day) patients than in the Ca-restricted (250 mg/day) ones. Oral Ca loading resulted in a smaller weight gain, a greater urinary sodium excretion, and an increase in red cell Mg. In the experimental study, high Ca (4% CaCl2) intake attenuated the blood pressure elevation in DOCA-salt-treated rats, accompanied with an increase in urinary sodium excretion, with the resultant attenuation in intra- and extracellular sodium retention. The decrease in catecholamine contents of hearts was improved, and a higher survival rate was observed in Ca-supplemented DOCA-salt rats. The results suggest that Ca supplementation may prevent a rise in BP in salt-dependent hypertension by inducing natriuresis with the resultant attenuation in sodium retention. The altered intracellular Mg level in hypertensive patients and the normalization of enhanced sympathetic nervous activity in DOCA-salt rats may, in part, be involved in its mechanism.
authors.affiliation: Department of Internal Medicine, Sanda Municipal Hospital, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Saito
authors.forename: H
authors.initials: H
authors.lastname: Sano
authors.forename: Y
authors.initials: Y
authors.lastname: Furuta
authors.forename: J
authors.initials: J
authors.lastname: Yamanishi
authors.forename: T
authors.initials: T
authors.lastname: Omatsu
authors.forename: Y
authors.initials: Y
authors.lastname: Ito
authors.forename: H
authors.initials: H
authors.lastname: Fukuzaki
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D002136:Calcium, Dietary / Q000008:administration & dosage*; D003900:Desoxycorticosterone / Q000494:pharmacology; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009318:Natriuresis; D051381:Rats; D011921:Rats, Inbred WKY; D012965:Sodium Chloride / Q000008:administration & dosage*
chemical_list: D002136:Calcium, Dietary; D003900:Desoxycorticosterone; D012965:Sodium Chloride