Valine, Leucine, and Isoleucine Metabolism by Lactating Bovine Mammary Tissue

Abstract

Valine, leucine and isoleucine were extracted by the lactating bovine mammary gland in excess of outputs in milk protein. 14C uniformly labeled L-valine, L-leucine or L-isoleucine were catabolized when incubated in vitro with lactating bovine mammary tissue slices. The pathways of degradation of these amino acids by mammary tissue appear to be those common to other tissues. These amino acids represent a potential source of energy to the mammary gland as well as a source of C and .alpha.-amino N for synthesis of nonessential amino acids.