Disturbed calcium metabolism in offspring of hypertensive parents.
To assess a possible heritability of a disturbed calcium metabolism in relation to blood pressure regulation, 28 young normotensive offspring of either hypertensive or normotensive parents were studied while administered a defined diet with daily sodium chloride of 6 and 20 g/day for 7 days each. Before the high salt diet was begun, the cytosolic calcium concentration ([Ca2+]i) in platelets was elevated in offspring of hypertensive parents, whereas serum electrolytes, plasma renin activity, plasma catecholamines, and 24-hour urinary excretion of sodium and calcium showed no difference between the two groups. On exposure to a high salt diet, the mean blood pressure increased (from 80 +/- 2 to 85 +/- 2 mm Hg, p less than 0.05) in offspring of hypertensive parents. These changes in mean blood pressure were positively correlated with the basal platelet [Ca2+]i (r = 0.61, p less than 0.01), whereas [Ca2+]i did not demonstrate any significant changes. When the subjects were administered the high salt diet, plasma ionized calcium decreased (from 2.37 to 2.21 meq/l, p less than 0.05) and 1,25-dihydroxyvitamin D3 increased (from 32.7 to 40.8 pg/ml, p less than 0.05) with a transient relative hypercalciuria in offspring of hypertensive parents. This increase of 1,25-dihydroxyvitamin D3 was significantly correlated with the changes in mean blood pressure (r = 0.62, p less than 0.01). Disturbed intraplatelet and systemic calcium metabolism may be of predictive value in the development of hypertension.
Yamakawa
H
H
Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan.
Suzuki
H
H
Nakamura
M
M
Ohno
Y
Y
Saruta
T
T
D000293:Adolescent; D001792:Blood Platelets / Q000378:metabolism; D002117:Calcitriol / Q000097:blood; D002118:Calcium / Q000097:blood / Q000378:metabolism* / Q000652:urine; D004039:Diet, Sodium-Restricted; D006801:Humans; D006973:Hypertension / Q000235:genetics*; D008297:Male; D008499:Medical Records; D009318:Natriuresis; D010281:Parathyroid Hormone / Q000097:blood; D012016:Reference Values
D010281:Parathyroid Hormone; D002117:Calcitriol; D002118:Calcium