The regulation of glutamine and ketone-body metabolism in the small intestine of the long-term (40-day) streptozotocin-diabetic rat.
The regulation of glutamine and ketone-body metabolism in the small intestine of the long-term (40-day) streptozotocin-diabetic rat.
复制标题
长期（40天）链脲佐菌素糖尿病大鼠小肠谷氨酰胺和酮体代谢的调节。
DOI：
10.1042/bj2420061
复制
发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Smith,EM
中科院分区：
文献类型：
--
作者：
Watford,M;Erbelding,EJ;Smith,EM
小肠是哺乳动物体内谷氨酰胺利用的主要部位。在长期（40天）链脲佐菌素糖尿病大鼠有一个显着增加的大小和磷酸盐激活的转氨酶活性的小肠。尽管这种增加的能力，肠谷氨酰胺利用停止在糖尿病大鼠。糖尿病大鼠的平均动脉谷氨酰胺浓度下降了50%以上，这表明底物可用性是导致肠道谷氨酰胺使用减少的原因。当动脉谷氨酰胺浓度升高，糖尿病大鼠谷氨酰胺溶液的输注，谷氨酰胺摄取跨门静脉引流内脏观察。研究了其他呼吸燃料对肠道谷氨酰胺代谢的影响。输注酮体不影响非糖尿病大鼠门静脉引流内脏对谷氨酰胺的利用。长期糖尿病对小肠中3-酮酸CoA-转移酶的活性或离体肠细胞中酮体利用率没有影响。谷氨酰胺（2 mM）的利用率降低，从糖尿病大鼠分离的肠上皮细胞相比，从对照动物。然而，肠上皮细胞匀浆中的转氨酶活性未受糖尿病影响。在从糖尿病大鼠分离的肠上皮细胞中，添加酮体或辛酸盐可减少谷氨酰胺的使用。有人提出，在长期糖尿病酮体，可能脂肪酸，取代谷氨酰胺作为主要的呼吸燃料的小肠。
The small intestine is the major site of glutamine utilization in the mammalian body. During prolonged (40-day) streptozotocin-diabetes in the rat there is a marked increase in both the size and the phosphate-activated glutaminase activity of the small intestine. Despite this increased capacity, intestinal glutamine utilization ceases in diabetic rats. Mean arterial glutamine concentration fell by more than 50% in diabetic rats, suggesting that substrate availability is responsible for the decrease in intestinal glutamine use. When arterial glutamine concentrations in diabetic rats were elevated by infusion of glutamine solutions, glutamine uptake across the portal-drained viscera was observed. The effect of other respiratory fuels on intestinal glutamine metabolism was examined. Infusions of ketone bodies did not affect glutamine use by the portal-drained viscera of non-diabetic rats. Prolonged diabetes had no effect on the activity of 3-oxoacid CoA-transferase in the small intestine or on the rate of ketone-body utilization in isolated enterocytes. Glutamine (2 mM) utilization was decreased in enterocytes isolated from diabetic rats as compared with those from control animals. However, glutaminase activity in homogenates of enterocytes was unchanged by diabetes. In enterocytes isolated from diabetic rats the addition of ketone bodies or octanoate decreased glutamine use. It is proposed that during prolonged diabetes ketone bodies, and possibly fatty acids, replace glutamine as the major respiratory fuel of the small intestine.