烧伤血清加缺氧条件下高牵张对心肌细胞的影响

目的研究烧伤血清加缺氧条件下,高牵张对心肌细胞的影响,探讨高负荷在严重烧伤后对心肌细胞的作用.方法采用原代培养的乳鼠心肌细胞,给予正常血清(SN组)、烧伤血清 缺氧(1%O2)(SH组)、烧伤血清 缺氧(1%O2) 10%轴向静态牵张(SHS组)3种刺激, MTT法检测心肌细胞活力、并测定培养上清中乳酸脱氢酶(LDH)和肌酸激酶(CK)的活力来反映心肌细胞受损程度.结果和正常血清比较,烧伤血清 缺氧刺激在1、3 h对心肌细胞活力无明显影响,6 h明显降低心肌细胞活力(P<0.01), LDH和CK活力在1 h已经明显升高(P<0.01);和前两者比较,烧伤血清 缺氧 牵张刺激对细胞活力影响在1 h就已经明显(P<0.01),LDH和CK活力呈现出爆发式的增高,最高可为正常组的50倍,同时相点烧伤SH组的5～6倍.结论在烧伤血清合并缺氧条件下,高负荷加剧了心肌细胞的损伤.

High stretch aggravates the damage to cardiomyocytes under burn sera and hypoxia

Objective To investigate the effects of high stretch on cardiomyocytes under burn sera and hypoxia in order to explore the effects of high load on cardiomyocytes after severe burn. Methods Cardiac ventricular myocytes isolated from neonatal rats were employed as the target cells. The cells were respectively stimulated by sera from normal rat, burn sera plus hypoxia and burn sera plus hypoxia and 10% axial static stretch. The viability of cardiomyocytes was determined using MTT assay, and the degree of damages on cardiomyocytes by detection of the activities of lactate dehydrogenase (LDH) and creatine phosphokinase (CK). Results Compared with that in normal group, the cell viability decreased mildly at 1 and 3 h after cells were stimulated by burn sera plus hypoxia and decreased markedly at 6 h after stimulation (P<0.01). The activities of LDH and CK increased significantly at 1 h after stimulation (P<0.01). Compared with that in the former two groups, the cell decreased significantly by burn sera plus hypoxia and 10% axial static stretch at 1 h, and the activities of LDH and CK increased at a very high level which reached 70-80 times as much as those in the normal group and 5-6 times as much as those in burn sera plus hypoxia group at the same time point. Conclusion High stretch can aggravate the damage to cardiomyocytes uner burn sera combined with hypoxia.