Effects of Growth Factors on the Enzymes of Purine Metabolism in Culture of Regenerating Rat Liver Cells

AbstractHepatocytes are affected by many cytokines and growth factors during liver regeneration. In regenerating rat liver cells cultures, liver cell growth factor (LCGF), hepatic stimulator substance (HSS), interleukin-1β (IL-1β), as well as their combination, were tested for their ability to activate the enzymes involved in purine metabolism. The enzymes tested were 5' nucleotidase, AMP deaminase, adenosine deaminase and xanthine oxidase.The cytokines alone or in combination, activated 5' nucleotidase and adenosine deaminase. Activity of AMP deaminase was stimulated by IL-Iβ associated with LCGF, HSS and IL-1β. Xanthine oxidase was stimulated by IL-1β but not with HSS and LCGF. Associated with IL-1β these two substances decreased its activity.A novel approach to the understanding of the mechanisms involved in the regulation of purine metabolism during liver regeneration, is proposed.