Expression Of Cardiomyocyte Atrial Natriuretic Peptide And Endothelin And Effects Of Losartan In Obesity Mice With Left Ventricular Hypertrophy

Objective:LVH is an independent risk factor of cardiovascular disease,which has been playing an important role in the development of childhood simple obesity(CSO).LVH can induce many cardiovascular diseases complication,including heart failure,myocardial ischemia, ventricular arrhythmia,cerebral apoplexy,suddenly death and so on.Consequently the diversion of LVH becomes not only the hot topic of decreasing of death rate of cardiovascular disease,but also the most important evidence of assessing intervening effect of medicine which decrease CSO.Many studies indicate that angiotensinⅡ(AngⅡ),atrial natriuretic peptide(ANP),and endothelin(ET)play an important role in the process of left ventricular remodeling of cardiovascular diseases.By establishing experimental animal model of obesity,to study the change of left ventricular mass index(LVMI),ANP,ET and the relationship among these in the heart of rats with left ventricular hypertrophy(LVH)induced by high fat diet,and to probe the effect of losartan(angiotensinⅡreceptor blocker)on these and provide theoretical evidence for early clinical prevention of childhood obesity.Method:Animal model of obesity was established by high fat diet,30 Wistar rats were randomly divided into two groups:normal control group(n=10)and hyperlipidemia group(n=20), 20 Wistar rats were fed with high-fat diet to set up the animal model of obesity and 10 rats with control chow serving as control group.The hyperlipidemia group was divided into two groups, including losartan group(preparation-taken group,n=10)and LVH group(preparation-non-taken group,n=10).The losartan group was given losrtan in dosage of 10 mg·kg^-1·d^-1,normal control group and LVH group was given distilled water without drugs at same dosage.After 4 weeks, rats were sacrificed and the hearts were collected.The change of LVM and LVMI was calculated; the level of ANP and ET was measured by radioimmunology assay.Result:①compared with normal control group,LVM and LVMI were significantly increased in the LVH group(P＜0.05),ANP and ET level were remarkedly enhanced in the LVH group(P＜0.05);②compared with the LVH group,LVM and LVMI were significantly decreased in the losartan group(P＜0.05),ANP and ET level were remarkedly decreased in the losartan group(P＜0.05);③The LVMI was positive correlation with ANP and ET level,there was also positive correlation of ANP and ET level with LVM.Conclusion:①Left ventricular hypertrophy has been established at the fourth week by given high fat feed,the change and relationship of ANP and ET play a important role in inducing LVH;②The adminstration of losartan for four weeks effectively improved high fat feed induced left ventricular hypertrophy,losartan could inhibit the secretion of ANP and ET in the left ventricular tissues.