The Role of High Calcium Diet Supplementation on L-NAME induced High Blood Pressure in Pregnant Rats

Abstract

Background: Hypertension in pregnancy with or without proteinuria is one of the foremost reasons of maternal death and morbidity in the world. This study investigated the role of a high calcium diet (HCa) in N G -nitro-L-arginine methyl ester (L-NAME) administered to pregnant rats. Methods: Thirty-two female rats of the Sprague-Dawley strain were randomly assigned into 4 groups of control, L-NAME (0.3g/ L of water), L-NAME + HCa (2.5%), and HCa diet (2.5%) group. Following confirmation of mating, HCa was administered from day 3 to day 18 of pregnancy while L-NAME was administered from day 12 to 18. The rats were sacrificed on the 19th day and blood pressure measurements were obtained. Blood and placenta were collected for biochemical and oxidative assays. Results: Blood pressure was reduced in L-NAME + HCa rats compared with L-NAME (p<0.05). Placenta and fetal weight were decreased in rats receiving L-NAME, L-NAME + HCa and HCa compared with control (p<0.05). HCa diet had no effect on L-NAME impaired oxidative status. No significant difference was observed in the liver enzymes and CRP levels across the groups. However, there was a significant reduction in the platelet count of L-NAME + HCa and HCa groups when compared with the control and L-NAME. Calcium and magnesium levels in the serum and placenta homogenate were not different but their excretion was significantly increased in the urine samples of the L-NAME + HCa and HCa groups. Conclusion: This study showed that HCa reduced the blood pressure of pregnant rats administered L-NAME but had no effect on oxidative stress. This implies that HCa alone might not sufficiently ameliorate the negative effects of hypertension in pregnancy.