Smith C B, Sun Y
Laboratory of Cerebral Metabolism, National Institute of Mental Health, Bethesda, Maryland 20892, USA.
Am J Physiol. 1995 Apr;268(4 Pt 1):E735-44. doi: 10.1152/ajpendo.1995.268.4.E735.
Rates of valine incorporation into protein were measured under control and valine-"flooding" conditions and included correction for the degree of recycling of unlabeled valine derived from the steady-state breakdown of tissue protein into the precursor pool (tRNA bound). The correction factor lambda, which is the ratio of the steady-state specific activity of valine in the tissue tRNA-bound pool to that in the arterial plasma, was determined for each of the tissues. In controls, values of lambda ranged from 0.31 in adrenals to 0.54 in heart; in flooded animals, values were higher, but only in liver was the value of lambda close to 1.0. In control and flooded rats, rates of protein synthesis were highest in liver and adrenals and lowest in skeletal muscle, with intermediate values in brain and heart. Flooding resulted in increased rates of protein synthesis in liver and decreased rates in adrenals. Rates of protein synthesis in brain, heart, and skeletal muscle were not statistically significantly affected by flooding.
在对照和缬氨酸“过量”条件下测量了缬氨酸掺入蛋白质的速率，并对从组织蛋白质稳态分解进入前体池（结合tRNA）的未标记缬氨酸的再循环程度进行了校正。校正因子λ，即组织中结合tRNA池的缬氨酸稳态比活性与动脉血浆中缬氨酸稳态比活性的比值，针对每个组织进行了测定。在对照中，λ值范围从肾上腺的0.31到心脏的0.54；在过量动物中，值更高，但只有肝脏中的λ值接近1.0。在对照和过量大鼠中，蛋白质合成速率在肝脏和肾上腺中最高，在骨骼肌中最低，在脑和心脏中为中间值。过量导致肝脏中蛋白质合成速率增加，肾上腺中蛋白质合成速率降低。脑、心脏和骨骼肌中的蛋白质合成速率未受到过量的统计学显著影响。
