肿瘤坏死因子对谷氨酰胺调控大鼠肝蛋白质合成的影响

The effects of TNF on the regulations of glutamine for liver protein synthesis in rats

目的:研究肿瘤坏死因子(TNFα-)对谷氨酰胺(G ln)调控大鼠肝蛋白质合成的影响。方法:将30只雄性SD大鼠,随机分为A(TPN)组;B(TPN+G ln)组;C(TPN+G ln+TNFα-)组,均行72 h全肠外营养。B组加用丙氨酰谷氨酰胺二肽,其中G ln剂量为0.3 g/(kg.d),计72 h。C组在B组的基础上于实验结束前24 h持续静脉滴注TNFα-,速度为5μg/(kg.h)。所有大鼠均在实验结束前0.5 h,一次性静脉注射L-15N亮氨酸1.0 mmol/kg。实验结束时,分别测定血浆中TNFα-浓度,血浆及组织中G ln浓度,并测定肝组织的蛋白质合成率。结果:B组血浆及肝组织中G ln浓度高于A组,但两组均低于C组;B组肝蛋白质合成率高于A组,C组低于B组。结论:TNFα-能升高血浆及肝组织中G ln的浓度;G ln能促进肝蛋白质合成;而G ln这种促肝蛋白质合成作用可被TNFα-抑制。

Objectives：The study was desigued to observe the regulations of glutamine metabolism by TNF-α. Methods ： Thirty male SD rats were assigned into three groups ： A （ TPN）, B （ TPN ＋ Gin）, C （TPN ＋ Gin ＋TNF-α）. At the last 0.5 hour, all animals were maintained with [L-^15N] ]eucine. Plasma TNF-α levels concentrations of glutamine plasma and in tissues were measured as the experiment ended after 72 hours, and the fractional synthesis rates（FSR） were also assessed. The glutamine concentrations of plasma and liver were increased markedly in group B and C. FSR was increased in group B and decreased in group C. Conclusions：The results indicated that TNF-α could increase the levels of glutamine in plasma and tissues and attenuate promoting protein synthesis of glutamine in tissues.