Reference ranges and methodological aspects in the urinary measuring of lysozyme, malate-dehydrogenase, gamma-glutamyltransferase and alpha-glucosidase.

The urinary excretions of lysozyme (LYS), malate-dehydrogenase (MAD), gamma-glutamyltransferase (GGT) and alpha-glucosidase (AGL) were measured in a group of normal subjects in basic conditions, during forced diuresis, at different hours of the day and with urinary collection periods of different lengths. The results have been expressed in the principal ways used in clinical practice. The best way to express the excretions of GGT and AGL was with the fractional excretions. For LYS and MAD, the fractional clearances appeared to be theoretically valuable. They were not significantly influenced by sex or by the different urinary collections. Forced diuresis caused a significant scattering of enzymuria.