Alteration of rat liver proteoglycans during regeneration

Abstract Sepharose CL-6B column chromatography of crude extracts from the slices of regenerating rat livers after partial hepatectomy and sham-operated controls labeled with [ 35 S]sulfuric acid revealed an enhancement of [ 35 S]sulfate incorporation into proteoglycan fractions during regeneration. The 35 S-labeled proteoglycans contained heparan sulfate (more than 80% of the total) and chondroitin/dermatan sulfate. The 35 S-incorporation into both glycosaminoglycans increased to maxima 3–5 days after partial hepatectomy and decreased thereafter toward the respective control levels. When [ 35 S]sulfuric acid was replaced by [ 3 H]glucosamine, similar results were obtained. These results suggest that the maximal stimulation of proteoglycan synthesis in regenerating rat liver follows the maximal mitosis of hepatic cells 1–2 days after partial hepatectomy. The 35 S-labeled proteoglycans from regenerating liver 3 days after partial hepatectomy and control were analyzed further. They were similar in chromatographic behavior on a gel filtration or an anion-exchange column and in glycosaminoglycan composition. Their glycosaminoglycans were indistinguishable in electrophoretic mobility. However, these proteoglycans were slightly but significantly different in their affinity to octyl-Sepharose and in the molecular-weight distribution of their glycosaminoglycans.