[Age-related changes in glycosaminoglycans in the cell nuclei of the rat liver--biochemical and histochemical pilot studies].

Cell nuclei of the livers of 12 male Wistar rats aged 24 months, and 16 male Wistar rats aged 4 months were isolated. 0.4 microCi [3H]-glucosamine/kg body weight were administered intraperitoneally. The livers of four animals were used for each biochemical analysis. The tissue was degraded by proteolysis, the glycosaminoglycans (GAGs) were isolated and the GAG types were determined by enzyme digestion, nitrite degradation and radiometry. The amount of GAGs was photometrically determined in single samples of pooled material of each of the two age groups. In paraffin sections (from other male Wistar rats of a different age), the influence of enzymes on specific GAG staining was observed. Most of the radioactivity was found in heparan sulfate (HS) and a lower content in chondroitin sulfates (CSs). In HS the incorporation increased with increasing age. The amount of HS showed no age-related differences. The results indicate an age-related activation of the HS metabolism. The GAG pattern and the age-related changes of the GAG types in total tissue (earlier results) are different from those in the nuclei. By histochemical methods, we observed a small but distinct effect of heparitinase in the cell nuclei.