Expression of transient receptor potent ial channel isoforms in rats with ventricular hypertrophy / 中华地方病学杂志

ABSTRACT

Objective To study the expression of transient receptor potential channel (TRPC) isoforms (TRPC1,3,4,5,6,7) inrats with cardiac hypertrophy.Methods Thirty adult male SD rats,weighing 200-240 g were divided into surgical group (model group,20 rats) and sham group (control group,10 rats) by random number table according to body weight.Aortic coarctation surgery was performed to establish a rat model of myocardial hypertrophy and the control group did not ligate thoracic aorta,but the same surgical procedure with the model group was performed.After 10 weeks,echocardiography was used to check changes of cardiac function; cardiac tissues of rats were weighed and cardiac hypertrophy index was calculated.Cardiac HE staining was used for observation of myocardial tissue morphological changes.Quantitative RT-PCR method was used for measuring the mRNA expression of TPRC isoforms (TRPC1,3,4,5,6,7).Western blotting assay was applied to detect the protein expression of TRPC4 and TPRC5 in hypertrophic cardiac tissue of rats.The relationship between cardiac hypertrophy exponential and TRPC4,TRPC5 protein expression was studied.Results Echocardiography showed that the septal thickness and posterior wall thickness in model group increased significantly compared with those of the control group [mm(2.64 ± 0.31) vs.(1.89 ± 0.15),(2.30 ± 0.14) vs.(1.60 ± 0.09),t =9.19,8.57,all P ＜ 0.05].Compared with the control group,cardiac hypertrophy index was significantly increased in model group [(3.21 ± 0.15)vs.(1.82 ± 0.10)mg/g,t =17.02,P ＜ 0.01].HE staining of myocardium showed that cardiomyocyte hypertrophy,abnormal nuclear morphology and significantly enlarged nuclear,and hyperplasia of myocardial interstitial fibrous connective tissue could be seen in model group.The mRNA expression of TRPC4 and TRPC5 was significantly increased in the model group as compared to those of the control group (1.51 ± 0.48 vs.1.22 ± 0.25,1.65 ± 0.35 vs.1.27-± 0.87,t =3.55,4.65,all P ＜ 0.05).The protein expression of TRPC4 and TRPC5 was significantly increased in the model group as compared to those of the control group (1.00 ± 0.54 vs.1.45 ± 0.68,1.00 ± 0.65 vs.1.58 ±0.93,t =5.51,7.10,all P ＜ 0.05).The protein expression of TRPC4 and TPRC5 were associated with cardiac hypertrophy index (r =0.728,0.681,all P ＜ 0.05).Conclusion Expression of TRPC4 and TRPC5 is increased in rats with cardiac hypertrophy.