INFLUENCE OF VALINE FLOODING ON CHANNELING OF VALINE INTO TISSUE POOLS AND ON PROTEIN-SYNTHESIS

Rates of valine incorporation into protein were measured under control and valine-''flooding'' conditions and included correction for the de gree of recycling of unlabeled valine derived from the steady-state br eakdown of tissue protein into the precursor pool (tRNA bound). The co rrection factor lambda, which is the ratio of the steady-state specifi c activity of valine in the tissue tRNA-bound pool to that in the arte rial plasma, was determined for each of the tissues. In controls, valu es 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 lambd a close to 1.0. In control and flooded rats, rates of protein synthesi s were highest in liver and adrenals and lowest in skeletal muscle, wi th intermediate values in brain and heart. Flooding resulted in increa sed rates of protein synthesis in liver and decreased rates in adrenal s. Rates of protein synthesis in brain, heart, and skeletal muscle wer e not statistically significantly affected by flooding.