KETO-ANALOGUE INCORPORATION INTO PROTEINS

这个项目的主要目的是开发一种实用的技术 用于定量单个支链酮酸 相对于蛋白质，（转氨作用后）被掺入蛋白质中。 因此，将相应的氨基酸如此施用（这 比率被称为“R”），并看看R如何随蛋白质摄入量而变化， 给药、不同的BCKA以及肾脏和肝脏疾病。 一 将给出3 H标记的BCAA和相应的14 C标记的BCKA 同时静脉注射或通过鼻胃管，使用预充注射， 持续输液 分离的蛋白质中的14 C/3 H比率除以 在注射液中相同的比例，得到R。 此外，具体活动 循环亮氨酸（或缬氨酸）在平台期的含量可以估计 白蛋白合成速率（取决于某些假设）。 白蛋白 降解率可以从随后的标记下降中估计 白蛋白。 R将在唾液粘蛋白、血浆白蛋白和 红细胞球蛋白，看看这三个R是如何相互关联的。 变量来 研究将包括蛋白质摄入量（在正常受试者中），i. v. 鼻胃途径（正常受试者和患者），酮酸治疗（ 患者）和缬氨酸对亮氨酸。

The principal purpose of this project is to develop a practical technique for quantitating the degree to which individual branched-chain ketoacids become incorporated (after transamination) into proteins, relative to the incorporation of the corresponding amino acids administered as such (this ratio is termed "R"), and to see how R varies with protein intake, route of administration, different BCKA's, and renal and hepatic disease. A 3H-labelled BCAA and the corresponding 14C-labelled BCKA will be given simultaneously i.v. or by nasogastric tube, using a priming injection and constant infusion. The ratio 14C/3H in an isolated protein, divided by the same ratio in the injectate, gives R. In addition, the specific activity of circulating leucine (or valine) at plateau makes possible an estimate of albumun synthesis rate (subject to certain assumptions). Albumin degradation rate can be estimated from the subsequent decline in labelling of albumin. R will be measured in salivary mucin, plasma albumin, and erythrocyte globin, to see how these 3 R's are interrelated. Variables to be studied will include protein intake (in normal subjects), i.v. vs. nasogastric route (in normal subjects and patients), ketoacid therapy (in patients), and valine vs. leucine.