| Objective To research for the delayed myocardioprotection of Jiaweidanshenyin(JDSH) preconditioning and the mechanisms of cell signal transduction.Methods 1. Thirty-two chronically instrumented conscious rabbits successfully underwent the following protocol. On day 1, rabbits were randomly divided into four groups: sham (saline, duodenum), IPC (four 5-min coronary artery occlusion/10-min reperfusion cycles), DPC(Jiaweidanshenyin, 5.86g /kg , duodenum), and I/R(saline, duodenum). On day 2 (24 h later), rabbits(except sham) underwent a 60-min coronary artery occlusion and 120-min reperfusion. Myocardial morphological changes were observed by optics microscope and electron microscope, infarct size (percentage of the area at risk and at infarction) was determined by triphenyltetrazolium chloride(TTC) and Evan's blue dye , lead Ⅱelectrocardiogram(ECG) and left ventricle pressure were registered by RM-6280 Multichanne1 Recording and Analyzing System, adenosine, nitric oxide synthase(NOS) and calcitonin gene-related peptide(CGRP) in serum were mensurated. 2. Cultured neonatal rat cardiac muscle cells(CCMCs) were randomly divided into seven groups: serum control(SC, 50%rat serum ,5%CO2,95%02), drug serum control(DC, 50%rat serum with Jiaweidanshenyin , 5%CO2,95%02 ), H/R(hypoxia/reoxygenation, 5%CO2,95%02), HPC (hypoxic preconditioning, four 10-min hypoxia(100%N2)/15-min reoxygenation(5%CO2,95%02)cycles), HPC+8-PT (HPC+0.1mg/ml 8-phenyltheophylline), DPC(50% rat serum with Jiaweidanshenyin), DPC+8-PT(50% rat serum with Jiaweidanshenyin +0.1mg/ml 8- phenyltheophylline).After 24h, above groups underwent the culture with hypoxia/reoxygenation(60-min 100%N2 and 120-min 5%CO2,95%02 ) except control and serum control. Creatinekinase(CK) and lactodehydrogenase(LDH),nitric oxide(NO) and endothelin(ET) in condition culture media were determined, protein kinase C(PKC) activity was mensurated by adulterating γ-32P-ATP, transcription of heat shock protein 70 message RNA(HSP70 mRNA) and nuclear factor kappan B message RNA(NF-κB mRNA) were estimated by reversed transciptive PCR(RT-PCR).Results 1. A few of cardial fibrin ruptured , partial hemorrhage and a mass of inflammatory cell soakaged at I/R group rabbits. Above changes were improved at IPC and DPC rabbits. 2. Jiaweidanshenyin preconditioning and ischemia preconditioning could markedly reduce the percentage of infarction size and the percentage of the area at risk(P<0.01), which DPCwas superior to IPC in reducing the percentage of the area at risk..3. Jiaweidanshenyin preconditioning and ischemia preconditioning could antagonize the fall of left ventricle systolic pressure(LVSP) and left ventricle diastolic pressure(LVDP), and had no effect on the changes of maximal rise velocity(+dp/dt max) and maximal fall velocity(-dp/dt max).4. Markedly slowering cardiac ratio(CR), uplifting ST segment or T wave inversion and cardiac arrhythmia(87.5%) in standard lead Ⅱelectrocardiogram occurred at I/R group. Jiaweidanshenyin preconditioning and ischemia preconditioning could obviously improve the changes of ST segment or T wave and cardiac arrhythmia(50% and 37.5%) and could not affect the changes of CR.5. CK and LDH contents in condition media of H/R group were higher than that of serum control group and drug serum group(P<0.01). To compare with H/R group, Jiaweidanshenyin preconditioning and ischemia preconditioning could obviously inhibit the increase of CK and CK contents(P<0.01). 8- phenyltheophylline could maekedly eliminate the effect of HPC and could not completely eliminate the effect of DPC.6.The release of endogenous adenosine was obviously promoted in rabbits of Jiaweidanshenyin preconditioning and ischemia preconditioning, of these, the effect of IPC was more outstanding. Compared with sham group, contents of endogenous adenosine obviously decreased(P<0.01).7. Total nitric oxide synthase(tNOS) and configuration nitric oxide synthase(cNOS) activity markedly decreased in rabbits of I/R group (P<0.05 and P<0.01) , and obviously incre... |
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