摘要目的 探讨支链氨基酸(BCAA)强化的早期肠内肠外营养支持对肝硬化大鼠肝部分切除术后肝功能及血浆氨基酸谱的影响,为临床合理应用提供实验依据.方法 将24只雄性SD肝硬化大鼠按编号法随机分为肠内营养组、肠内营养+BCAA组和肠外营养+BCAA组3组,3组大鼠行肝部分切除术后1 d分别进行等热量等氮量营养支持,共5 d.术后6 d测定大鼠体重、肝功能、前白蛋白、转铁蛋白、肝组织白蛋白 mRNA的表达、Ki67蛋白表达指数及进行血浆氨基酸谱分析.结果 与术前比较,术后肠内营养、肠内营养+BCAA、肠外营养+BCAA组大鼠体重均减轻(P＜0.05).术后肠外营养+BCAA组较肠内营养组碱性磷酸酶水平升高(P＜O.05);肠外营养+BCAA组较肠内营养+BCAA组血清天冬氨酸氨基转移酶、丙氨酸氨基转移酶、碱性磷酸酶水平升高(P＜0.05).术后肠外营养+BCAA组较肠内营养、肠内营养+BCAA组血清前白蛋白水平降低(P＜O.05),转铁蛋白差异无统计学意义(P＞O.05).肠外营养+BCAA、肠内营养+BCAA组较肠内营养组血浆中亮氨酸、异亮氨酸明显升高,酪氨酸、苯丙氨酸、精氨酸、色氨酸明显降低(P＜0.05);肠外营养+BCAA组与肠内营养+BCAA组比较,各氨基酸浓度差异均无统计学意义(P＞0.05).肠外营养+BCAA、肠内营养+BCAA组较肠内营养组总氨基酸及芳香族氨基酸均降低,BCAA及BCAA/芳香族氨基酸比值升高(P＜0.05).肠外营养+BCAA组较肠内营养、肠内营养+BCAA组肝组织白蛋白mRNA表达水平及Ki67蛋白表达指数均降低(P＜O.05).结论 BCAA强化的肠内肠外营养支持能改善肝硬化大鼠血浆氨基酸失衡,恢复血浆中BCAA/芳香族氨基酸比值;肠内营养在改善肝功能、促进肝脏蛋白质合成和肝硬化大鼠肝切除术后残肝肝再生方面优于肠外营养,但仍不能提高血浆白蛋白水平.

abstractsObjective To evaluate the effects of branched-chain amino acids-enriched early parenteral and enteral nutrition on the liver function and serum aminograms in cirrhotic rats after partial hepatectomy. Methods In this prospective randomized controlled study, 24 cirrhotic rats, induced by thioacetamide, were randomized into three groups: enteral nutrition (EN) group, EN + branched-chain amino acid (BCAA) group, and parenteral nutrition (PN) + BCAA group. After receiving partial hepatectomy, rats in all three groups were nutritionally supported with equal amount of calorie and nitrogen contents from the 1st postoperative day ( PO day 1 ) to PO day 5. On PO day 6, parameters including body weight, liver functions, prealbumin, transferring, and serum aminograms were measured or determined, and the level of liver albumin mRNA was detected by reversal transcription-polymerase chain reaction and morphological examinations such as HE staining and immunohistochemical staining, which were assessed by index of Ki67 protein index. Results Body weight was significantly decreased in all three groups on PO day 6 (P ＜0.05 ). Compared with EN + BCAA group, serum aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase after partial hepatectomy were significantly higher in PN + BCAA group (P ＜0.05 ). Serum alkaline phosphatase level was significantly higher in PN + BCAA group than in EN group ( P ＜0. 05). The level of prealbumin was significantly lower in PN + BCAA group when compared with EN group or EN +BCAA group ( both P ＜ 0. 05 ), although no such significant difference was noted in terms of transferrin ( P ＞0. 05 ). The levels of leucine and isoleucine elevated while those of tyrosine, phenylalanine, arginine and tryptophan declined in PN + BCAA group or EN + BCAA group when compared with EN group ( P ＜ 0. 05 ). Aminograms were not significantly different between EN + BCAA group and PN + BCAA group ( P ＞ 0. 05 ). Levels of total amino acid and aromatic amino acid (AAA) were significantly lower while BCAA and ratio between BCAA and AAA (BCAA/AAA) were significantly higher in PN + BCAA group or EN + BCAA group than in EN group (P ＜ 0. 05 ).Significantly lower level of albumin mRNA and index of Ki67 were observed in PN + BCAA group than in EN group or EN + BCAA group (P ＜ 0.05 ) on PO day 6. Conclusions BCAA-enriched EN or PN reverses amino acid disequilibrium and restores BCAA/AAA in cirrhotic rats after partial hepatectomy. Compared with PN, EN is superior in improving postoperative liver function, promoting protein synthesis, and speed up tissue regeneration in the postoperative liver. However, it still can not restore serum albumin in a short term.