Effect of Ca~(2+) channel blocker on the levels of myocardial calcineurin A?mRNA in right ventricle and plasma NO,nitric oxide synthase and endothelin-1 in rats with chronic hypoxia / 中国医师杂志

ABSTRACT

Objective Many studies showed that Ca~(2+) channel blocker could prevent and treat right ventricular hypertrophy(RVH) induced by chronic hypoxia.To further identify the mechanism,we investigated the effect of Ca~(2+) channel blocker on the levels of myocardial calcineurin A?mRNA(CnA?)in RV and plasma nitric oxide(NO),NO synthase and endothelin-1(ET-1) in rats with chronic hypoxia.Methods 30 rats were divided into three groups by randomized block design: treatment group with Amlodipine Besylate ablets [(30 mg?kg~(-1)?d~(-1)),administered via gavage],chronic hypoxia group,and control group.The rats in treatment group and chronic hypoxia group were exposed to normobaric chronic hypoxia [(10.0?0.5)% O_2 ] for 21 days.On the 21st day of experiment,all rats were sacrificed and the hearts were collected for measuring the weight.Blood samples were also drawn from the ventricles for measuring plasma NO,iNOS and ET-1 levels.CnA?mRNA levels in RV were measured by RT-PCR.Results ⑴The RV/(LV+S)、RV/BW ratios were significantly higher in chronic hypoxia group than those of control group and treatment group(P