Enzymuria of the rat: biorhythms and sex differences

Alanine aminopeptidase, gamma-glutamyltransferase and N-acetyl-beta-D-glucosaminidase were measured daily over 65 days in 24-hour urine of male and female Wistar rats. The mathematical evaluation was based on the Fourier-analysis. The excretion of alanine aminopeptidase and gamma-glutamyltransferase was higher in male than in female rats. This sex-dependent difference was not observed for N-acetyl-beta-D-glucosaminidase. The excretion of the 3 enzymes followed a biorhythm with a dominant period of 7 days for gamma-glutamyltransferase and N-acetyl-beta-D-glucosaminidase and one of 9 days for alanine aminopeptidase. Biorhythms and sex differences of enzymuria should be considered in experimental designs.