Abstract
Experimental studies was performed on the effect of polished rice as protein source in the diet on biosynthesis of protein-bound lipoic acid using Nose and Mori's method. Rats were divided into seven groups : polished rice standard group, lysine-, methionine-, tryptophan-, threonine- and phenylalanine-deficient groups and polished rice groups. The weight gains of body and liver were the following order : standard group or methionine-deficient, phenylanine- and tryptophan-deficient groups, lysine- and threonine deficient groups and polished rice group. The incorporation rate per mg N in liver mitochondrial protein (LMP) decreased in polished rice group and tryptophan- and threonine-deficient groups, and the rates in methionine-, lysine- or phenylalanine deficient groups were the same as that of standard group. When ^<35>S-labeled lipoic acid was injected, the incorporation rate per mg N in LMP was remarkably increased until 30 minutes, but in the polished rice group the increasing rate was slower than standard group, and in threonine-deficient group the decreasing was faster than others.
