【摘要】 目的:建立稳定性核素([L1-5N]亮氨酸)测定大鼠小肠蛋白质合成率的方法。方法:分别测定静脉注射相同剂量[L1-5N]亮氨酸不同时相的大鼠小肠15N丰度及不同剂量[L1-5N]亮氨酸同一时相的大鼠小肠15N丰度。结果:大鼠小肠游离氨基酸池中15N核素丰度在注射后0.5 h内呈线性上升并达高峰,维持4 h后缓慢下降,小肠蛋白质中的15N丰度0.5 h至12 h基本维持不变;随着注射剂量的增加,大鼠小肠蛋白质分数合成率(FSR)亦增加,当[L1-5N]亮氨酸剂量在1.0mmol/kg以上,FSR并不随施加[L1-5N]亮氨酸剂量的加大而增加。结论:在进行大鼠小肠蛋白质合成率测定时,一次性静脉注射的测量最佳时限为0.5 h,剂量为1.0mmol/kg。更多还原

【Abstract】 Objective: To develop a new technique for measuring synthesis rates of small intestinal protein in rats with [L-14N]Leucine. Methods: After intravenous injection of [L-14N]Leucine,the enrichment of ¹⁵N in different time intervals with the same dosage and at fixed time by various dosage were measured. Results: During the period from 0 to 30 minutes,there is nearly a linear increase in enrichment of ¹⁵N of free amino-acid pool to the peak in rats’ small intestine.For bond amino-acid pool,the level of enrichment of ¹⁵N is at its plateau between 0.5 and 12 hours with the increase of dosage,FSR did not rise with the increasing dosage of more than 1.0 mmol/kg of [L-14N]Leucine,there is no significant discrepancy. Conclusion: For measuring synthesis rate of small intestine protein in rats,30 minutes after mainlining is optimal and the most suitable dosage of [L-14N] Leucine is 1.0 mmol/kg.更多还原