大鼠心脏缺血／再灌心肌细胞表面阴离子位点的改变

CHANGES OF THE ANIONIC SITE AT THE SURFACE OF ISCHEMIC-REPERFUSED MYOCARDIAL CELLS IN RAT

以聚乙烯亚胺为阳离子探针，用透射电镜观察大鼠心脏局部缺血／再灌后心肌细胞表面阴离子位点和心肌超微结构的变化，并用分光光度法检测心肌唾液酸含量。发现缺血／再灌损伤心肌细胞表面阴离子位点减少。其减少程度与超微结构损伤严重程度呈平行关系，并与心肌唾液酸含量的降低密切相关。提示心肌细胞表面阴离子位点的变化可反映缺血／再灌时心肌损伤的程度。

he purpose of this study was to acquire more understanding about the myocardial surfacedamage during ischemia-reperfusion(I/R)at the molecular level.In the I/R in vivo model ofrats,aIterations of the anionic site at the myocardial cell surface were assessed quantitatively witha PEl cationic probe. The influence of I and I/R on the anionic sites density(ASD)was ob-served.The relationship between the sialic acid content(SAC)and ASD was verified by usingthe biochemical method. Rats were divided into 4 groups(n=5,per group),control(A),is-chemia 30 min(B),ischemia 30 min reperfusion 30 min(C),ischemia 30 min reperfusion 60min(D).Part of the myocardiaI tissues was put to PEI under electron microscopy. The other partwas homogenated for biochemical determination of SAC.The results showed that ASD in GroupA,B,C and D was 155.74±3.72,128.32±5.28,88.46±2.88 and 69.37±2.48(N/μm2)respec-tively(B<A,C and D<B,D<C,P<0.01).The decrease of ASD was paralleled to the degreeof ultrastructural damage. SAC of group A,B,C and D was decreased progressively.As com-pared with A,the percentage contents of Groups B,C,D were reduced to 14%,35%,51%,re-spectively.There was correlation between SAC and ASD(r=0.9200,P<0.01).It indicatesthat decrease of anionic sites is a result of the surface damage of myocardial cells caused by I andI/R.The molecular basis for the decrease of anionic sites lies in reduced amounts of sialic acid.