This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Prada, J. A. Articles by Clark, K. E. Search for Related Content PubMed PubMed Citation Articles by Prada, J. A. Articles by Clark, K. E.

Hypertension, Vol 23, 695-702, Copyright © 1994 by American Heart Association

ARTICLES

Hypocalcemia and pregnancy-induced hypertension produced by low-calcium diet

JA Prada, RC Tsang and KE Clark
A.E. Seeds Perinatal Research Center, Cincinnati, OH.

Recent studies from our laboratory in fasting pregnant ewes with twin gestation have implicated low serum calcium concentration in the etiology of hypertension in pregnancy. We hypothesized that the reduction in serum calcium concentration produced by feeding of a calcium-deficient diet in twin gestation would lead to a significant increase in maternal arterial blood pressure, vascular resistance, and protein in the urine and decreased uterine blood flow. Twenty-five instrumented ewes were used in the present study. After surgery a calcium-deficient diet and deionized water (calcium ion free) were provided ad libitum to 19 animals. Blood pressure, cardiac output, heart rate, and uterine blood flow were monitored every other day. Six control animals were provided with standard Rumilab diet and tap water (group 1). Animals on a low-calcium diet (group 2) were subdivided according to the blood ionized calcium response to low dietary calcium intake. Non-hypocalcemic animals were assigned to group 2a (n = 10), and hypocalcemic animals (calcium concentration below two standard deviations from the control group) were assigned to group 2b (n = 9). In group 2b calcium concentration decreased from 1.03 +/- 0.04 mmol/L on day 110 of gestation to 0.77 +/- 0.03 mmol/L by day 125 of gestation. Arterial blood pressure increased significantly from 76 +/- 2 to 91 +/- 2 mm Hg, and uterine blood flow decreased from 950 +/- 53 to 579 +/- 48 mL/min. Urinary protein increased from 1.7 +/- 0.3 to 10.5 +/- 1.2 g/L.(ABSTRACT TRUNCATED AT 250 WORDS)