Bengtsson F, Bugge M, Herlin P, Nobin A, Jeppsson B
Department of Surgery, Lund University, Sweden.
JPEN J Parenter Enteral Nutr. 1989 Jan-Feb;13(1):65-70. doi: 10.1177/014860718901300165.
Increased brain concentrations of tryptophan, and presumably thereby increased brain serotonin metabolism, have been observed following liver impairment and implicated in the etiology of portal-systemic encephalopathy (PSE). Increased plasma-free tryptophan (ie, not albumin-bound) concentrations can be expected after exogenous fat administration. This might further increase the brain serotonin metabolism in liver failure and negatively influence the PSE. We treated rats 2 weeks after end-to-side portacaval shunt (PCS) with continuous intravenous infusion of fat emulsion (Intralipid 20%) for 24 and 72 hr, respectively. The regional serotonin turnover was determined in different regions of the central nervous system (CNS) by measuring 5-hydroxyindole concentrations after NSD 1015 decarboxylase inhibition. The results revealed no further increase of the CNS serotonin turnover after fat infusion to PCS rats, compared with PCS rats given equal amounts of glucose. Thus, continuous infusion of a fat emulsion caused no major alteration of the CNS serotonin metabolism in PCS rats.
肝脏损伤后可观察到脑内色氨酸浓度升高，推测由此导致脑内5-羟色胺代谢增加，并与门体循环性脑病（PSE）的病因有关。外源性脂肪给药后，血浆游离色氨酸（即未与白蛋白结合的色氨酸）浓度有望升高。这可能会进一步增加肝功能衰竭时脑内5-羟色胺的代谢，并对PSE产生负面影响。我们分别对端侧门腔分流术（PCS）2周后的大鼠持续静脉输注脂肪乳剂（英脱利匹特20%）24小时和72小时。通过在NSD 1015脱羧酶抑制后测量5-羟吲哚浓度，测定中枢神经系统（CNS）不同区域的5-羟色胺周转率。结果显示，与给予等量葡萄糖的PCS大鼠相比，向PCS大鼠输注脂肪后，CNS的5-羟色胺周转率没有进一步增加。因此，持续输注脂肪乳剂不会引起PCS大鼠CNS 5-羟色胺代谢的重大改变。
