| ObjectiveTo study the action of Pretreatment to isolated rabbit hearts with the Potassium ionic channel opener Nicorandil and the opium recepter Excitation opener U50588H by improve Langendorff perfusion model. The preservation action was observed for the Nicorandil to re-perfuse the isolated rabbit hearts to relieve calcium ions overloading and to preserve time. To observed the preservation effect for isolated rabbit hearts with improved St.Thomas II solution, to explore a new operative preservation way for the isolated heart in clinical heart transplantation. Method1. The Langendorff perfusion assembly was used to set up perfusion model for isolated hearts.2. The Nicorandil was added into ST,Thomans II solution as isolated hearts' preservation solution for study group I (K+ was 8mmol/L). To observe the variation of Cardiac function restoration, cardiac muscle cell calcium ions, myocardium Adenosine triphosphate (ATP), myocardium enzyme, the water in myocardium, myocardium ultrastructure, et al. The University of Wisconsin solution (UW) as a kind of preservation solution was used for isolated hearts in control group.3. On the base of Nicorandil Pretreatment and Nicorandil solution to hypothermia preserve the isolated hearts for 8h, moreover added the Nicorandil into the Krebs-Hensleit solution to perfuse the isolated rabbit hearts, to observe its protection effect for isolated rabbit hearts. The control group that was Pretreatment by Nicorandil and Nicorandil solution to preserve in hypothermia the isolated hearts for 8h.4. The U50488H was added into ST.Thomans II solution as a kind of isolatedhearts' preservation solution for study group II (K+ was 8mmol/L). To observe the variation of Cardiac function restoration, cardiac muscle cell calcium ions, myocardium ATP, myocardium enzyme, and the water in myocardium, myocardium ultrastructure, et al. To compare with the different for the isolated rabbit hearts between in this group and Nicorandil Pretreatment group.5. Experiment animals the big white rabbits were pretreatment by Nicorandil or U50,488H before anesthetized.6. According to the different preservation times for the isolated rabbit hearts, the experiment animals were divided into four time points to observe: four hours; six hours; eight hours and ten hours. About the Nicorandil re-perfusion, we only observed the isolated hearts that were preserved for eight hours group.7. Read-in the Cardiac function markers about the isolated hearts before them were perfuse the cardioplegia solution. To assay the left ventricular developed pressure (LVDP), left ventricular pressure differential and integral calculus (眃p/dt), coronary artery flow (CF) and to compute the percentage for Cardiac function recover; Assay the myocardium enzyme (lactate dehydrogenase, LDH; the cardiac muscle phosphokinase, CK) from the coronary artery drainage solution , the Content of calcium in myocardium mitochondrion, sarcoplasmic reticulum Ca2+-ATPase activity, ATP content in myocardium, myocardium water content and to obverse the myocardium ultrastructure.Result 1. There wasn't obviously difference for the rate of the cardiac function recover between test group and control group when the preservation time less then six hours (P>0.05) ,but the rate of the cardiac function recover there was obviously difference in two groups(p<0.05); at ten hours the cardiac function recover there wasn't obviously difference (P > 0.05) .2. Nicorandil Pretreatment could safeguard the Ca2+-ATPase activity, meanwhile it could relieve calcium ions overloading. About the Ca2+-ATPase activity at the same time there was obviously difference between test group and controlgroup(p<0.01); After eight hours, the mitochondrion calcium ions there were obviously difference (p<0.05).3. Nicorandil Pretreatment could obviously improve myocardium structural; UW solution could cause Severity injury for coronary artery endothelium, this made the recovery rate of the corona... |
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