构建脓毒症大鼠ICU获得性衰弱模型的研究

Study on the establishment of an ICU-acquired weakness model in rats with sepsis

目的构建ICU获得性衰弱大鼠模型。方法健康雄性SD大鼠72只,随机分成12组(对照3、6、9d组;制动3、6、9d组;LPS3、6、9d组;LPS加制动3、6、9d组),各6只,LPS组和LPS+制动组腹腔注射脂多糖内毒素(LPS),对照组和制动组腹腔注射等体积生理盐水。经上述处置后,将制动组和LPS+制动组大鼠于固定器制动至各分组时间点。于各分组时间点处死大鼠,测量实验前后大鼠体重;留取膈肌及双侧腓肠肌标本行HE染色,采用RT-PCR法检测E3泛素连接酶基因Atrogin-1、Murf1mRNA表达水平。结果LPS+制动组较其他各组体重明显下降,肌纤维横径显著减小(P<0.05);且较其他各组腓肠肌和膈肌Atrogin-1、Murf1mRNA相对表达量显著增高(P<0.05)。结论腹腔注射LPS加制动可作为一种简便的构建ICU获得性衰弱大鼠模型的方法。

Objective To establish an intensive care unit(ICU)-acquired weakness model in rats with sepsis. Methods A total of 72 healthy male SD rats were randomly and equally divided into 12 groups(3 d, 6 d and 9 d control groups;3 d, 6 d and 9 d immobilization groups;3 d, 6 d and 9 d LPS groups;and 3 d, 6 d and 9 d LPS+immobilization groups immobilization groups;n=6). The rats in LPS groups and LPS + immobilization groups were injected intraperitoneally with lipopolysaccharide(LPS), and the rats in control and immobilization groups were injected intraperitoneally with the same volume of normal saline. And then, the rats in the immobilization group and the LPS +immobilization group were kept in the immobilization apparatus for immobilization until the corresponding time points. All rats were sacrificed at appropriate time points. The weight of each rat before and after test was measured, samples of diaphragm and bilateral gastrocnemius were taken for hematoxylin-eosin(HE) staining, and then the RT-PCR method was used to test the expressions of E3 ubiquitin ligase gene Atrogin-1, Murf1 and m RNA. Results The weight in the LPS +immobilization group was reduced much more than in the rest groups, and the transverse diameter of muscle fiber was significantly lower(P < 0.05);and the expression of Atrogin-1, Murf1 and mRNA in diaphragm and bilateral gastrocnemius was significantly higher(P < 0.05). Conclusion The combination of intraperitoneal injection of LPS and immobilization can simplify the establishment of an ICU-acquired weakness model in rats.