Glyoxalase activity in sham- and partially hepatectomized rats.

In male rats, hepatic glyoxalase activity and reduced glutathione, the cofactor for this enzyme system, approximately double 12 hr after partial (2/3) or sham hepatectomy, in which the liver lobes were handled during the sham operation. These changes precede by 10 to 12 hr the anticipated DNA synthesis after partial hepatectomy and by about 24 hr the smaller, but prolonged, DNA synthesis that occurs in peripheral hepatic cells after this type of sham hepatectomy. These findings indicate that the hepatic glyoxalase system is responsive to operative stress prior to increments in DNA synthesis and mitosis. Whether or not it regulates intracellular levels of methylglyoxal, a cell growth inhibitor, and thereby regulates cell division as postulated by Szent-Györgyi, remains to be established.