RESUMO
BACKGROUND: In hospital patients suffering from adverse clinical and biochemical symptoms of malnutrition, it is often necessary to employ parenteral nutrition to avoid the body's tissue becoming broken down by being metabolised. Thus, the patient's welfare and survival can be supported throughout any periods of medical crisis. Two of the enzymes responsible for metabolising glycoconjugates are alpha-fucosidase (FUC) and beta-glucuronidase (GLU), present in lysosomes. They release fucose or glucuronic acid from the non-reducing end of oligosaccharide chains. OBJECTIVE: To determine the effect of parenteral nutrition administered to ill patients, on glycoconjugate metabolism, by measuring serum and urinary activities of FUC and GLU. Material and methods. Blood samples and the daily urine collection were taken from 23 patients' who had been undergoing parenteral nutrition for either 5 or 10 days, as well as from a baseline sample. Enzyme activities in serum and urine were determined by the method of Zwierz et al. RESULTS: Serum FUC activities were significantly lower after 10 days compared to 5, (p< 0.0172), whereas GLU activities were significantly lower after both 5 and 10 days, (p< 0.0007 and p< 0.0208 respectively), compared to levels before starting parenteral nutrition. GLU activities were however higher after 10 days than those after 5 days, (p< 0.0023). In urine, FUC activities were significantly decreased after 10 days compared to 5 days after starting parenteral nutrition, (p< 0.0245). Urine GLU activities were unaffected by parenteral nutrition nor was any effect seen on FUC or GLU activities when calculated per 1mg creatinine. CONCLUSIONS: Serum FUC and GLU activities can be used for assessing the effect of parenteral nutrition on glycoconjugate metabolism. The significant decreases of serum GLU activity observed after 5 and 10 days, may serve to indicate that the components of parental nutrition are appropriate and that the body has become suitably adapted to this form of nutrition.