In vivo deacetylation of N-acetyl amino acids by kidney acylases in mice and rats. A possible role of acylase system in mammalian kidneys.

Deacetylations of N-acetylhistidine and N-acetyltryptophan were examined in vivo by their administration to mice and rats. N-Acetylhistidine accumulated preferentially in the kidney and was converted to histidine effectively by acylase I. Similar deacetylation of N-acetyltryptophan by acylase III was also observed. Acylase I and III activities in mouse kidney increased in parallel remarkably at the period of weaning. A hypothesis that the acylase system in mammalian kidneys is a mechanism acquired to utilize amino acids from exogenous and endogenous acyl derivatives including those derived from protein hydrolysis was offered.