Experimental Study On The Protective Effects Of Hypothermic St.Thomas â…¡ Solutions Containning NaHS On Isolated Rat Heart

Emphasis on organ preservation solution that can increase the time of isolated heart is urgent for heart preservation. Hyperpolarization myocardial preservation solution was one of the hot spot with which the heart can be preserved efficiently , and can avoid being damaged by ionic flow when depolarized,and can extend the quiescent period of the Electric- mechanical activity ,and can protect significantly the systolic function of LV. In the middle 1990's, People found that the endogenous H2S is a kind of KATP channel opener.The related experiments have indicated that mouse is in suspended animation-like when which was put in the position filled with exogenous H2S (the concentration differ from0 to80μl/L).The CBT,MR and oxygen capacity decrease significantly.So we design the experiment that compare the protective effects between the STH and the HST and research the initial mechanism of H2S. Objective To evaluate the protective effects of a novel hyperpolarized cardiac preservation solution with different concentration of NaSH on isolated rat heart . The experiment includes two parts:to establish the working model of isolated rat heart;the protective effects of hypothermic St.ThomasⅡsolutions containning different concentration of NaSH on isolated rat heart. The different protective effects between the STH and the HST can reveal the mechanism of HST. The different protective effects among HST with different concentration of NaSH can help us sieve the optimization concentration.Methods1,The convenient, efficient and practical method for working model of isolated rat heart was established after repeated practices. The isolated hearts were perfused in the Langendorff working model for functional evaluation with the help of electrophysiolograph . Heart rat and +dp/dtmax can be measured in 20,40,60 minutes with which the stability of the working model can be certifiered.2,To observe the protective effect and to investigate the mechanism of isolated rat heart preserved in HST. The isolated hearts were perfused in the Langendorff rat model for functional evaluation before and after preservation. ATP in myocardium and cardiac ultrastructure were measured after reperfusion. At the same time, different concentration of NaSH were put in STH. After preservation the rate of functional recovery, LD, glycogen were compared among the three Group. With that the optimization concentration was sieved. Results 1,The isolated hearts were fused in the Langendorff working model. The functional evaluations for Group 20min,Group 40min and Group 60min were insignificant differences. The working model was repeatability and steady .2,After preservation for 6h, the recovery of coronary flow in Group HST was better than Group STH. And the contents of ATP,LD,glycogen in Group HST were significant differences between Group STH.3,HST with the concentration of 4×10-1 mmol/L NaHS can protect rat heart for 6 h effectively. So many index measured are positive compared to the STH. However, the protective effects of HST with the concentration of 4 mmol/L NaHS was worse than STH.Conclusions1,The method being the character of simply manipulating and good repeatability can upgrade and establish the working cast of isolated rat heart by Langendorff rat mode.2,HST was positive to elevate the preservative effectiveness of isolated hearts.The possible mechanism is H2S possess the effectiveness that to promote the open of KATP channel, to distend the Coronary Artery, to inhibit the oxidative phosphorylation of myocardium, to defend the function of cytochondriome, to prevent the exhaust of energy reserve, to form the buffer pair hampering the intra-cellular acid-intoxication.3,The concentration of 4×10-1 mmol/L NaHS has better preservation effect. High concentration H2S solution for myocardial preservation is harmful to heart. HST solution can protect rat heart for 6 h effectively. The concentration of 4×10-1 mmol/L NaHS has better preservation effect and HST cardioplegia solution is more effective than STH cardioplegia solution. High concentration H2S solution for myocardial preservation is harmful to heart.