含中链甘油三脂的脂肪乳剂有利于胃切除术后大鼠的脂类代谢和抗氧化能力

研究胃切除大鼠于术前接受以中链甘油三酯或长链甘油三酯为脂肪来源的肠外营养对肝内脂类，炎性介质和抗氧化能力的影响。大鼠经颈内静脉插管，分成两组接受肠外营养治疗。肠外营养的能量为30kcal/kg/d， 脂肪占能量的39％。除了脂肪乳剂外所有肠外营养制剂都是等氮的并含有相同的营养成分，脂肪乳剂的成分中链／长链（1：1）或长链脂肪乳剂。大鼠于接受肠外营养5天后经部分胃切除术，于术后24小时处死。研究结果显示，中逻／长链组肝内脂肪少于长链组。提示中链／长链脂肪乳剂能改善肝脏脂类代谢。两组大鼠的腹腔灌洗液（PLF）和血液中白介素－1β（Ⅱ-1β），白介素－6（Ⅱ－6）和肿瘤坏死因子α（TNF－α）无显差别，说明术前输入中链／长链脂肪乳剂对调节大鼠循环血液中的炎性介质和手术刺激没有影响。长链脂肪乳剂组的红细胞谷胱甘肽超氧化物酶（GSHPx)的活力明显高于输入中链／长链脂肪乳剂组，但红细胞超氧化物歧化酶（SOD）的活力在两组之间无显性差别。这些结果说明，腹部手术前输入中链／长链脂肪乳剂能改善脂类代谢和减少氧化物的刺激。结论：推荐对准备行胃手术的肠外营养支持的病人使用中链／长链脂肪乳剂。

Medium-chain triglyceride fat emulsion is recommanded for rats undergoing gastrectomy on lipid metabolism and antioxdative activity

This study was designed to investigate the effects of preinfusionwith total parenteralnutrition(TPN) using medium-chain triglyceride(MCT) versus long-chain triglyceride (LCT) emulsion as fat sources on hepatic lipids,inflammatory mediators and antioxidant capacity in rats undergoing gastrectomy.The rats with internal jugular catheter,were divided into two groups and received PN.PN provided 30 kcal/kg/d with 39% of the energy provided as fat.All PN solutions were isonitrogenous and identical in nutritent composition except for the fat emulsion,which was composed of MCT/LCT(1∶1) or LCT.After receiving PN for 5 days,the rats underwent partial gastrectomy,and were sacrificed 24 hours after surgery.Results of the study demonstrated that the MCT/LCT group had lower hepatic lipids than did the LCT group.It is indicated that MCT/LCT improved liver lipid metabolism in rats receiving gastrectomy.No differences in interleukin-1β(IL-1β),interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α) in peritoneal lavage fluid (PLF) and blood were observed between the two qroups.It is suggested infusion with MCT/LCT before surgical insult did not have an effect on modulating the production of inflammatory mediators in either circulating blood or the location of the surgical stimulus.Erythrocyte glutathione peroxidase (GSHPx) activity was significantly higher in the LCT group than the MCT/LCT group,whereas erythrocyte superoxide dismutase (SOD) activity did not differ significantly between the two groups.These results suggest preinfusion with MCT/LCT may have beneficial effect in improve lipid metabolism and reducing oxidative stress in rats with abdominal operation.It is concluded that MCT/LCT is more recommended as compared with LCT for TPN subjects undergoing gastrectomy.