Fractional flux rates of<i>N^τ</i>-methylhistidine in skin and gastrointestine: the contribution of these tissues to urinary excretion of<i>N^τ</i>-methylhistidine in the rat

Abstract

1. Fractional flux rates of N τ -methylhistidine (3-methylhistidine; Me-His) of skin and gastrointestine were measured by administering [ methyl - 3 H]methionine to rats. 2. The results showed that the contribution of these tissues to urinary excretion of Me-His was at least 16.6 %. This means that when fractional catabolic rates of myosin and actin were estimated from urinary excretion of Me-His, the part of Me-His derived from skin and gastrointestine should not be neglected.