Dexamethasone administration induces increased glutaminase specific activity in the jejunum and colon.
Dexamethasone administration induces increased glutaminase specific activity in the jejunum and colon.
复制标题
地塞米松给药诱导空肠和结肠中谷氨酰胺酶比活性增加。
DOI：
10.1016/0022-4804(88)90181-3
复制
发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Rombeau,JL
中科院分区：
文献类型：
--
作者：
Fox,AD;Kripke,SA;Berman,JM;McGintey,RM;Settle,RG;Rombeau,JL
外源性糖皮质激素显著增加肠道对谷氨酰胺的摄取和利用。由于谷氨酰胺是小肠的主要氧化燃料，我们研究了糖皮质激素是否会诱导介导谷氨酰胺降解（谷氨酰胺酶）和合成（谷氨酰胺合成酶）的酶的比活性的变化。雄性Sprague-Dawley大鼠接受为期7天的基本饮食。第5天，将动物随机分为4组，分别给予生理盐水（对照组）或地塞米松剂量0.1 mg/kg (Lodex)；0.3 mg/kg (Middex)；或0.6 mg/kg （Hidex）。48小时后，测定空肠和结肠段蛋白、谷氨酰胺酶和谷氨酰胺合成酶活性。地塞米松（Hidex）应激剂量显著提高了大鼠空肠和结肠谷氨酰胺酶特异性活性（P< 0.02， P< 0.05）。这些数据表明糖皮质激素通过增加肠道谷氨酰胺酶的比活性来增加肠道对谷氨酰胺的利用的机制。
Exogenous glucocorticoids markedly increase thein vivouptake and utilization of glutamine by the intestine. Since glutamine is the major oxidative fuel for the small intestine, we investigated whether glucocorticoids induce changes in the specific activity of the enzymes that mediate glutamine degradation (glutaminase) and synthesis (glutamine synthetase). Male Sprague-Dawley rats received a 7-day elemental diet. On Day 5, animals were randomized to one of four groups and received either saline (Control) or one of three doses of dexamethasone im: 0.1 mg/kg (Lodex); 0.3 mg/kg (Middex); or 0.6 mg/kg (Hidex). Forty-eight hours later jejunal and colonic segments were assayed for protein, glutaminase, and glutamine synthetase activity. A stress dose of dexamethasone (Hidex) produced a significant increase in both jejunal and colonic glutaminase specific activity (P< 0.02 vs Control andP< 0.05 vs Control, respectively). These data suggest a mechanism whereby glucocorticoids increase the intestinal utilization of glutamine by increasing the specific activity of intestinal glutaminase.