腹部手术后中枢单胺类神经递质和外周血游离氨基酸的变化与术后疲劳的关系

目的研究腹部大手术后大鼠中枢单胺类神经递质含量的变化,探讨术后疲劳综合征中枢水平发生机制。方法将84只雄性成年SD大鼠随机分为疲劳评估组（包括模型组和假手术组）和实验组（分为术后1、3、5、7和14d恢复组及各组对应的对照组）。术后对大鼠进行疲劳评估,并在相应时间点取出大脑海马、中脑、下丘脑,检测脑组织5。羟色胺（5-HT）、去甲肾上腺素（NE）、多巴胺（DA）的含量及外周血游离色氨酸和支链氨基酸浓度。结果3个脑区5-HT变化趋势类似,在术后3d内明显升高,术后第5天降至最低,至术后第14天逐渐恢复至平稳状态,实验组间比较及实验组与相应对照组比较．差异均有统计学意义（P〈0．05）。海马和下丘脑NE和DA水平总体变化不明显,中脑NE和DA均在术后1d明显升高（P〈0．05）。外周血中游离色氨酸和游离色氨酸／支链氨基酸比值在术后早期升高后．至第5天降至最低．后期游离色氨酸仍低于对照组水平,而游离色氨酸／支链氨基酸比值和支链氨基酸恢复至对照组水平．实验组间比较及实验组与相应对照组比较．差异均有统计学意义（P〈0．05）。结论外周血中游离色氨酸和游离色氨酸／支链氨基酸比值及中枢5-HT水平的波动可能与腹部大手术后疲劳综合征的发生发展有着重要的联系。

Association of the changes of central serotonin and peripheral blood free amino acids with postoperative fatigue after abdominal surgery

Objective To explore the mechanism of postoperative fatigue syndrome (POFS) by detecting the change of central monoamine neurotransmitters in a rat model after major abdominal surgery.Method Eighty-four rats were randomly divided into fatigue assessment groups (including model group and sham group) and experimental groups (including postoperative day 1,3,5,7,and 14 recovery groups and the corresponding control groups).Postoperative fatigue was evaluated after surgery.The brains were removed thereafter to detect the levels of 5-hydroxytryptamine (5-HT),norepinephrine (NE),dopamine (DA) in the hippocampus,midbrain,hypothalamus by high performance liquid chromatography.Serum free tryptophan (f-Trp) and branched-chain amino acids (BCAA) were measured.Results The level of 5-HT increased to the highest at postoperative day 3,but reduced rapidly to the minimum at postoperative day 5,and then gradually recovered to the preoperative level.There was significant difference of 5-HT among experimental groups (P＜0.05),also between the postoperative 24 hrs group and control groups (P＜0.05).f-Trp and the ratio of f-Trp/BCAA increased in the early postoperative period,reduced to minimum at postoperative day 5.f-Trp was still lower compared to the control group at postoperative day 14,while the ratio of f-Trp/BCAA and BCAA restored to control level.Both of them were significantly different among experimental groups (P＜0.05),also between the experimental groups and control groups (P＜0.05).Conclusion Changes of f-Trp,the ratio of f-Trp/BCAA,and central 5-HT may play an important role in the development of POFS.