The Experimental Research Of Preservation Effects On HTK Solution Associating With Verapamil To Donor Heart

Objective:By manufacturing Langendorff perfusion model of isolated rat heart, preservating isolated rat heart at 4℃for 6 hours,then observing the recovery degree of the heart function after heart resuscitation and changes of myocardium.Through analysing the preserved effect,discussing the myocardial protection mechanism on the mixed liquid of verapamil and HTK solution.Methods:30 healthy SD male rats (weight 350-500g/pcs) were divided randomly to experimental group and control group, each group was treated with intraperitoneal pentobarbital anesthesia, after the success of caesarean section, then handle the heart to the Langendroff instrument. HTK solution was used as cardioplegic solution in control group,while the mixed liquid of Verapamil and HTK solution was used as cardioplegic solution in Experimental group. preservated isolated rat heart at 4℃for 6 hours.then refused with 37℃K-H solution and the heart resuscitated,Hemodynamic indexes and myocardial enzyme datas were recorded by multichannel physiologic recorder at initiation, and 20min,40min,60min,80min after resuscitation, took the coronary outflow liquid at the 45min after reperfusion,finally took the samples separately for biopsy and electron microscopic scanning.Results:1.4 cases was failed respectively because of unskillful handling operation,inserting the perfusion tube too deep,damage of the aortic valve,excessive diameter of the perfusion tube and low temperature, other 26 cases were manufactured successfully with the help of indoor heater, different diameters of perfusion needles, homemade balloon.2. Hemodynamic changes:There's obvious consistency in hemodynamic LVESP, LVSP,±DP/DT indexes between the two groups, the heart function returned to optimum at 40min after reperfusion, and decline more obviously after reperfusing for 60min. the descent speed in Experimental Group was slower than Control Group.LVEDP increased in control group,while increased before reperfusing for 60min,then descended in experimental group,3. Myocardial enzymology changes:the level of AST, CK, CK-MB and LDH1 was tested from the coronary outflow liquid at reperfusion for 45min,the level in Control Group was higher significantly than Experimental Group.4. Myocardial biopsy by HE staining showings: Control group:myocardial structure existed, a part of myocardial fibers arranged fitly, there's wide range of typical wave-like change in sarcomeres. Experimental group:myocardial structure existed, and myocardial fibers arranged fitly, cytoplasmic and myofibrillar colored lighterly.5.Myocardial sections scanning by electron microscopy: Control group:myocardial structure existed, part of the myocardial fibers dissolved, part of the Z-line was slightly blurred, mitochondria increased significantly, with little swelling, no obvious expansion in sarcoplasmic reticulum, without glycogen accumulation, nuclear and chromatin were not changed significantly. Experimental group:myocardial structure was more clearly, mitochondria and organelles haven't changed significantly(such as sarcoplasmic reticulum volume and morphology). without glycogen accumulation, nuclear and chromatin were not changed significantly.Conclusion:Under the conditions of low temperature and ischemia-reperfusion, there's a better effection of myocardial protection,using Verapamil-HTK solution as cardioplegic solution compare to HTK solution.