Glutamine-enriched total parenteral nutrition enhances plasma glutathione in the resting state
Glutamine-enriched total parenteral nutrition enhances plasma glutathione in the resting state
复制标题
DOI：
10.1006/jsre.1996.0077
复制
发表时间：
1996-02-15
影响因子：
2.2
通讯作者：
Wilmore, DW
中科院分区：
文献类型：
--
作者：
Denno, R;Rounds, JD;Wilmore, DW
谷胱甘肽(GSH)是细胞内主要的抗氧化剂，对细胞的正常功能和复制是必不可少的。半胱氨酸和其他硫醇化合物被认为是谷胱甘肽生物合成的限速物质，但最近的研究表明，谷氨酰胺(Gln)在代谢应激过程中是必不可少的，以补充已经耗尽的组织GSH水平。为了确定补充谷氨酰胺在静息、无应激状态下的作用，我们研究了三组Wistar大鼠。将动物随机分为三组：(1)自由饮食组静脉注射生理盐水(对照组)，(2)标准全肠外营养(STA-TPN)组，(3)谷氨酰胺强化全肠外营养(GLN-TPN)组。静脉喂养的动物没有得到老鼠的食物。以2.2ml/小时的速度输液，连续4天，在研究的第5天采集所有动物。Gln-TPN组血浆GSH水平显著高于STA-TPN组和对照组(P<；0.01)。各组大鼠肝脏GSH浓度、氧化GSH/还原GSH比值无明显差异。Gln-TPN组血浆ALT水平显著低于对照组(P<；0.05)。对照组ALP水平显著高于STA-TPN组和Gln-TPN组(P<；0.01)。其他肝功能指标在三组间均无显著差异。我们的数据表明，在这个模型中，富含谷氨酰胺的TPN在维持肝脏GSH储存的同时，提高了血浆GSH浓度。这表明GSH周转在谷氨酰胺强化的TPN过程中发生了改变，这可能解释了饮食中补充谷氨酰胺如何增强组织的抗氧化能力。(C)1996年学术出版社。
Glutathione (GSH) is the major intracellular antioxidant and is essential to normal cell function and replication. Cysteine and other thiol compounds have been considered rate-limiting for GSH biosynthesis, but recent studies have demonstrated that glutamine (GLN) becomes essential during metabolic stress to replete tissue GSH levels which have become depleted. To determine the role of GLN supplementation in the resting, nonstressed state, we studied three groups of Wistar rats. The animals were catheterized and randomly assigned to one of three groups: (1) chow ad libitum group receiving iv saline (control), (2) standard total parenteral nutrition (STA-TPN) group, and (3) glutamine-enriched TPN (GLN-TPN) group. The intravenously fed animals received no rat chow. The infusions were administered at a rate of 2.2 ml/hr for 4 days and all animals were harvested on the fifth day of study. The GLN-TPN group had a significantly higher plasma GSH level than STA-TPN or control animals (P < 0.01). The hepatic concentration of GSH and the oxidized GSH/reduced GSH were similar in all groups. GLN-TPN had a significantly lower plasma ALT level than the control group (P < 0.05). The control group had a significantly higher ALP level than STA-TPN and GLN-TPN animals (P < 0.01). There were no significant differences in other measures of hepatic functions among the three groups. Our data demonstrate that in this model GLN-enriched TPN enhances plasma GSH concentrations, while maintaining hepatic GSH stores. This suggests that GSH turnover is altered during glutamine-enriched TPN, which may explain how dietary GLN supplementation enhances tissue antioxidant capacity. (C) 1996 Academic Press, Inc.