Regulation of Glucosamine Synthesis in Injury and Partial Hepatectomy 1

Summary

The activity of glucosamine synthetase and the concentration of UDPAH were measured concomitantly in rat livers as a function of time following laparotomy and partial hepatectomy. Glucosamine synthetase activity increased significantly 24 to 48 hr after these treatments. The activity returned to normal levels 4 days after laparotomy but remained significantly elevated at 8 days following partial hepatectomy. UDPAH concentrations were not affected significantly at any time after laparotomy and were only slightly affected after partial hepatectomy. Fasting for 24 hr caused a significant decrease in glucosamine synthetase activity but did not affect the ability of the enzyme to respond to laparotomy or partial hepatectomy. Actinomycin D or cycloheximide administration completely blocked the increase in glucosamine synthetase activity after laparotomy. UDPAH pool sizes were not affected significantly by these treatments.