Changes in Polyamine Metabolism of Rat Liver After Administration of D-Galactosamine: Favorable Effects of Putrescine Administration on Galactosamine-Induced Hepatic Injury

There are many reports showing a close relation between polyamine metabolism and tissue growth or recovery of damaged tissues, such as regenerating liver. Thus, changes in polyamine metabolism in the livers from rats treated with D-galactosamine, an inducer of experimental hepatitis, were studied. The activity of ornithine decarboxylase started to increase 14 hr after administration of galactosamine and reached 30 times the normal activity at about 25 hr, the time of maximum severity of hepatitis. The content of putrescine increased to about 10 times the control value. After increases in the putrescine content and ornithine decarboxylase activity, the hepatitis started to diminish. Increases in the activity of S-adenosylmethionine decarboxylase and the content of spermidine were observed 33-37 hr after administration of galactosamine. The maximum values of these parameters, which were significantly higher than the control values, were observed after the healing process had started. Administration of putrescine to rats given galactosamine significantly decreased the severity of acute hepatitis, as judged by the activities of serum transaminases and hepatic glucose-6-phosphate dehydrogenase and by histologic findings. Other diamines, such as cadaverine or 1,3-diaminopropone, did not affect the levels of serum transaminases, but administration of spermidine to rats reduced the high levels of serum transaminases induced by golactosamine.