缺血和缺氧诱导离体SD乳鼠心肌细胞凋亡发生的实验研究

Study of Apoptosis in the Myocyte of Neonat Rat Induced by Ischemia in Vitro

目的:通过建立一种新的离体SD乳鼠心肌细胞的缺氧模型,探讨心肌细胞缺氧、缺血损伤后的心肌细胞凋亡及其时序分布特点。方法:SD乳鼠的培养心肌细胞随机分为5组:对照组,缺氧12h组(I12h)、缺氧24h组(I24h),缺氧48h组(I48h)以及缺氧72h组(I72h)。应用TUNEL法染色和透射电镜检测心肌细胞凋亡的改变。结果:I12h组心肌细胞中见少量的TUNEL阳性细胞,随缺氧时间的延长,TUNEL阳性细胞数量逐渐增多。I12h组的心肌细胞凋亡指数(AI)与对照组相比差异有统计学意义(P<0.01),I48h组、I72h组心肌细胞的AI值分别可达(24.4±2.41)%和(45.4±4.22)%。透射电镜观察各分析时相点心肌细胞,凋亡心肌细胞在I24h组出现,I48h组、I72h组最多见。结论:乳鼠心肌细胞缺氧模型可导致心肌细胞凋亡,凋亡程度和心肌细胞缺氧时间有关。细胞凋亡在心肌缺血、缺氧心肌细胞死亡中起重要作用。

Objective：To develop a new kind of model of ischemic neonate rat myocytes in order to compare the timing and extent of apoptosis isehemic rat myocytes in vitro. Methods：The neonatal rat myocytes were randomly divided into 5 groups： control groups, ischaemic 12h group （I12h）, ischaemic 24h group （I24h）, ischaemic 48h group （L48h） and ischaemic 72h group （I72h）. The cultured myocytes of each group were taken to detect apoptosis of myocytes by the TUNEL method and transmission electron microscopy （TEM）. Results： As early as 12h after hypoxia insult in this model, TUNEL-positive myocytes were detected. The cultured neonatal rat myocytes apoptosis indexes （AI） of the I12h group was significantly higher than that of the control group （P〈0.01）, Furthermore, the AI of the I48h group and the I72h group was （24. 4 ± 2. 14） % and （45.4 ± 4.22） %, respectively. TEM examination showed that apoptosis occurred in some myoeytes of the I12h group and reached a peak in the myocytes of the L48h group and the 172h group. Conelusion：These results indicate that isehaemia can induce apoptosis of cultured neonatal rat myocytes and the efficiency of apoptosis is related to the time-course of cultured myocytes after isehaemic insult. Apoptosis is an important form of the death of the cultured neonatal rat myoeytes after ischaemie insult.