早期肠内营养减轻“二次打击”肝损伤的肝功能指标比较

Comparison of liver functional parameters of protection effect of early enteral nutrition on liver from the "second insult" injury

目的早期肠内营养对危重症导致的"二次打击"时的肝脏具有保护作用,通过血清学检测筛选评价肝功能的敏感指标。方法建立大鼠失血性休克-内毒素腹腔注射的"二次打击"及肠内、肠外营养模型。根据营养方式分为3个大组,分别为肠内营养组(EN组)、肠外营养组(PN组)、混合营养组(EPN组)。每组均从术后12h开始给予肠内和/或肠外营养液,连续给液5d,分别在营养支持后第1、3、5天采血测定血清学指标,在第5天获取肝脏组织以免疫组化方法检测TLR4表达。结果术后第5天与第1天比较,视黄醇结合蛋白(RBP)在三组均逐日升高(P<0.01),转铁蛋白(TRF)、前白蛋白(PA)在EN、EPN组升高(P<0.01～0.05),腺苷酸脱氨酶(ADA)显著降低(P<0.01),γ-谷氨酰转肽酶(γ-GT)、碱性磷酸酶(ALP)在PN组升高(P<0.01～0.05);EN、EPN组与PN组比较在术后第5天:RBP升高,ALT、AST、ADA、γ-GT、ALP降低(P<0.01～0.05)。PN组较EN、EPN组TLR4表达增强。结论早期肠内营养支持减轻了"二次打击"给肝脏带来的损伤,肝功能得以恢复;RBP和ADA分别是反映机体营养状态和肝细胞损伤的敏感指标;TLR4有助于判断内毒素血症对肝脏的早期损伤程度。

Objective The effect of the early enteral nutrition on liver protection from the ＂second insult＂ injury caused by the critical diseases was detected by hepatic serology indicators. The aim of the study is to sift the sensitive indicators. Methods The rat models of ＂second insult＂ caused by hemorrhagic shocklipopolysaccharide intraperitoneal injection and enteral or parenteral nutrition were established. According to the nutrition types, the rats were divided into three groups including enteral nutrition group （group EN）, parenteral nutrition group （group PN） and compounded nutrition group （group EPN）. Nutrition was infused 12 h after operation and supplied for 5 consecutive days for each of group. Blood was taken on day 1, 3 and 5 for hepatic serology indicators determination. The rats were sacrificed on day 5 and the liver tissue was obtained. The expression of liver TLR4 protein was detected via immunohistochemistry assay. Results As compared with those of the 1st post-operation, retinol binding protein （RBP） increased day by day in all three groups; transferring （TRF） and prealbumin （PA） were elevated while adenine nucleotide deaminase （ADA） declined significantly in group EN and group EPN; glutamyl transpeptidase （γ-GT） and alkaline phosphatase （ALP） increased in group PN. Compared with those of group PN 5 days after operation, RBP increased, while ALT, AST,ADA,γ-GT,and ALP decreased markedly. TLR4 was high expressed in group PN comparing with that of group EN and group EPN. Conclusion The early enteral nutritional support protects the liver from the ＂second insult＂ injury, beneficial to liver functional restoration. RBP and ADA is the sensitive indicators reflecting the nutritional status and hepatocellular damage respectively. TLR4 con tributes to judging the early injury degree of endotoxia to liver.