Effect of metabolic acidosis on hindquarter glutamine and alanine release.
Effect of metabolic acidosis on hindquarter glutamine and alanine release.
复制标题
代谢性酸中毒对后躯谷氨酰胺和丙氨酸释放的影响。
DOI：
10.1016/0026-0495(86)90166-6
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
Welbourne,TC
中科院分区：
文献类型：
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作者：
Welbourne,TC
研究了慢性代谢性酸中毒大鼠后臀谷氨酰胺释放量与肾谷氨酰胺提取量的关系。用NH4CL维持大鼠4 d，诱导代谢性酸中毒；对照组配对喂食NH4HCO3。代谢性酸中毒使肾谷氨酰胺提取量增加8倍，动脉血浆谷氨酰胺浓度降低40%。由于动静脉谷氨酰胺浓度差增加和通过后躯的血流量显著增加，酸中毒时后躯谷氨酰胺释放量增加5倍。后节氨和谷氨酸的提取均增加了酸中毒，可占谷氨酰胺氮释放量的25%。代谢性酸中毒时，后肢丙氨酸释放量明显低于对照动物的谷氨酰胺释放量。酸中毒时丙氨酸氮释放量的减少占谷氨酰胺氮释放量的25%。因此，代谢性酸中毒以牺牲丙氨酸为代价刺激后躯谷氨酰胺的释放，并由更多的氨和谷氨酸的提取支持。然而，根据平衡研究，其他氮源必须提供近50%的谷氨酰胺氮释放。
The relationship between hindquarter glutamine release and renal glutamine extraction was studied in rats undergoing chronic metabolic acidosis. Metabolic acidosis was induced by maintaining rats on NH4CL for four days; controls were pair-fed NH4HCO3. Metabolic acidosis increased renal glutamine extraction 8-fold and decreased arterial plasma glutamine concentration 40%. Hindquarter glutamine release rose 5-fold in acidosis due to an increased arteriovenous glutamine concentration difference and a significant rise in blood flow through the hindquarters. Both ammonia and glutamate extraction in the hindquarter increased in acidosis and could account for 25% of the glutamine nitrogen released. Alanine release by hindquarters, which exceeded glutamine release in the control animals, was greatly depressed in metabolic acidosis. The reduction in alanine nitrogen release during acidosis could account for 25% of the glutamine nitrogen released. Consequently, metabolic acidosis stimulates hindquarter glutamine release at the expense of alanine and is also supported by greater extraction of ammonia and glutamate. However, other N sources must supply nearly 50% of the glutamine nitrogen released based on balance studies.