Expression Level Of Mineralcorticoid Receptor Gene In Obesity Mice And The Effect Of Losartan On Its Expression

Background:Many study reports showed that childhood obesity has been a big problem around the world.There is close relationship between childhood obesity and the adult cardiovascular diseases,and the obesity can cause ventrical hypertrophy of heart and ultimately lead to cardiovascular diseases.Recent studies showed that the increase of aldosterone level in obese children has a close relationship with the left ventrical hypertrophy,and the aldosterone is one of the main factors that trigger the remodeling of heart and increase the rate of heart diseases.Aldosterone performs these functions by binding to mineralcorticoid receptor(MR)in heart,however,there is no report showing whether there is expression change of MR gene in childhood obesity at present.Objectives:1.To investigate the expression level and the function of mineralcorticoid receptor gene in left heart hypertrophy by observing the expression change of 11β-HSD2 gene in pure obesity.2.To investigate the effect of Losartan on left ventricular hypertrophy and the expression level of mineralcorticoid receptor gene in pure obesity.Methods:1.Experimental groups:One month old Wister rats(n=30)were randomly divided into three groups:(1)Normal control group(n=10)(2)Non-mediation group(n=10)(3)Losartan treatment group(n=10)2.Obese animal model preparation:The obese animal model was made by feeding rats in obese and Losartan treatment groups with high fat feed for 9 weeks.,for the rats in normal control group,the common roughage was feeded.3.Intervention for each group:The rats in Losartan treatment group were given Losartan 10mg/kg.d,the rats in normal control and pure obesity groups were given saline 2ml/d.4.The morphology and the gene expression of hearts:After 13 weeks,the rats were sacrificed,the heart were isolated and the left ventricles were weighed.The expression level of gene was detected by reserve transcription polymerase chain reaction(RT-PCR)methods.5.statistical methodst:Data were recorded and dealt with spss 11.5 and were described in ((?)±S),Independent-sample t test,pearson correlation,variance analysis were used for statistical analysis.P values＜0.05 was to be statistically significant. Results:1.The expression level of 11 beta hydroxysteroid dehydrogenase(11β-HSD2)gene is higher in non-mediation group than that in normal control and Losartan treatment groups(P＜0.05);2.LVM is higher in non-mediation group than that in normal control and Losartan treatment groups(P＜0.05);3.LVMI is higher in non-mediation group than that in normal control and Losartan treatment groups(P＜0.05);.4.The expression of 11β-HSD2 gene is closely related to LVM and LVMI.Conclusion:From above results,we conclude:1.Obesity can induce hypertrophy of left ventricle of heart of young rats.2.Obesity can induce the expression levelof mineralcorticoid receptor gene in heart of young rats.3.The expression level of mineralcorticoid receptor gene in heart of young obese rats and the extent of left ventricle hypertrophy is positive correlation.4.Losartan can mitigate left ventricular hypertrophy and decrease the expression of mineralcorticoid receptor in young obese rats.