PLASMA LYSOSOMAL GLYCOHYDROLASES IN A GENERAL-POPULATION

In this study we evaluated the differences in plasma levels of some gl ycohydrolases of lysosomal origin that appear to be the most interesti ng for possible usefulness for diagnosis (N-acetyl-beta-D-glucosaminid ase, beta-D-glucuronidase, alpha-D-galactosidase, beta-D-galactosidase , alpha-L-fucosidase and alpha-D-mannosidase) in a general population of 417 subjects, as related to age and sex and also to body mass and t o some habits, such as smoking and consumption of alcohol. The enzymat ic activities were assayed by fluorimetric techniques with 4-methylumb elliferyl-glycosides as substrates. Particular attention was given to some technical aspects. Enzymatic activity was preserved by addition o f ethylene glycol and stable liquid material was employed for calibrat ion purposes, Blood was sampled rigorously at the same time of day and all the samples were obtained within a short period of time to exclud e effects of the circadian and circannual rhythms. beta-Glucuronidase levels were the most affected by sex and body mass. beta-D-Galactosida se was not affected by differences in age, sex, body mass or by smokin g, but appeared to be the most sensitive to modification by alcohol co nsumption. The data in this report emphasize that, whenever changes or differences in the levels of lysosomal enzymes in body fluids are stu died, it is essential to have a reference population rigorously correl ated with the study population. When possible, repetitive measurements in the same subject could better indicate a clinical trend.