Effects of in- utero exposure to oral nifedipine and labetalol on some reproductive indices in hypertensive pregnant wistar rats

Abstract

Thestudy investigated the effects of in utero exposure to oral nifedipine andlabetalol on some reproductive indices in hypertensive pregnant wistar rats. Thirty(30) pregnant female rats were randomly divided into six (6) groups of five (5)rats each and were treated as follows: Group 1: Normotensive pregnant controlrats, Group 2: Normotensive pregnantrats + 51.1mg/kg b w of Nifedipine, Group 3: Normotensive pregnant rats + 2.5mg/kg b w of Labetalol, Group 4:Hypertensive pregnant control rats, Group 5: Hypertensive pregnant rats +51.1mg/kg b w of Nifedipine and Group 6: Hypertensive pregnant rats + 2.5 mg/kgb w of Labetalol. Hypertension was induced in rats by using 8% sodium chlorideadded to their regular feeds for a period of eight weeks. The female rats weremated with fertile male rats in a ratio of 2:1. Treatment was given orally toanimals once daily throughout gestation period in all groups till ten (10) dayspostpartum. At the end of treatment, reproductive indices were calculated andall animals from each group were sacrificed at postnatal day 10 and the uteriwere excised and stained in few drops of 10% ammonium sulphide for ten (10)minutes to determine the implantation sites and post implantation losses. Theresults obtained revealed that the correlation of the implantation site withthe litter size indicated that post implantation loss of 9% recorded from ratsin the normotensive pregnant control group wassignificantly lower than the nifedipine (51.1mg/kg bw) and labetalol (2.5mg/kg b w) treated normotensivepregnant rats which had 25% and 45% post implantation lossesrespectively with labetalol (2.5mg/kg bw) treated normotensivepregnant group recording the highest post implantation loss. On theother hand, 11.1% of post implantation loss was also recorded from rats in the hypertensive pregnant control group which wassignificantly lower than the nifedipine (51.1mg/kg bw) and labetalol (2.5mg/kg b w) treated hypertensive pregnant animalswhich recorded 22.5% and 30.0% post implantation loss. It can be concluded thatthese anti-hypertensivedrugs may be involved in large percentage of implantation losses especially insubject with pre-existing or chronic hypertension in pregnancy that may requirethe drugs throughout gestation.