Protective Effect Of TRPM4 Channel Inhibitor 9-Phenanthrol On Myocardium In Puppies With Simulation Open Heart Surgery

Objective:To study the protective effect of transient receptor potential melastatin 4(TRPM4)channel inhibitor 9-Phenanthrol on myocardium in puppies with simulation open heart surgery.Methods: A total of eighteen healthy puppies(less than 8 weeks and similar weight)with the same species were selected,and these puppies were randomly divided into 9-Phenanthrol group(n=9)and control group(n=9).The control group was given normal saline for 20 minutes before cardiopulmonary bypass,and the 9-Phenanthrol group was given TRPM4 channel inhibitor 9-Phenanthrol in the first 20 minutes before cardiopulmonary bypass.And then,the levels of creatine kinase isoenzyme MB(CK-MB)and cardiac troponin I(cTn-I)in the serum of the two groups were respectively detected by ELISA at 30 minutes after aortic occlusion(T1)and 60 minutes(T2),1 hours after opening aorta(T3)and 2 hours(T4).Meanwhile,the immunohistochemistry and HE staining were used to analyze the expression of TRPM4 in the myocardic tissue.Results: The levels of CK-MB and cTn-I in serum of the control group and the 9-Phenanthrol group were gradually increased at the T1,T2,T3 and T4 moments,those indexes of serum in the 9-Phenanthrol group were significantly lower than those in the control group,the differences were statistically significant(P<0.05).Compared with the control group,the damage in myocardial tissue was much more slightly in the 9-Phenanthrol group,and the expression of TRPM4 protein in the puppies' myocardium was reduced than those in the control group.Conclusions: The application of TRPM4 channel inhibitor 9-Phenanthrol in simulation open heart surgery could protect the myocardium from ischemia-reperfusion injury to a certain extent.It has certain value for the future application in clinical experiment.