EFFECTS OF GROWTH-FACTORS ON THE ENZYMES OF PURINE METABOLISM IN CULTURE OF REGENERATING RAT-LIVER CELLS

Hepatocytes are affected by many cytokines and growth factors during l iver regeneration. In regenerating rat liver cells cultures, liver cel l growth factor (LCGF), hepatic stimulator substance (HSS), interleuki n-1 beta (IL-1 beta), as well as their combination, were tested for th eir ability to activate the enzymes involved in purine metabolism The enzymes tested were 5' nucleotidase, AMP deaminase, adenosine deaminas e and xanthine oxidase. The cytokines alone or in combination, activat ed 5' nucleotidase and adenosine deaminase. Activity of AMP deaminase was stimulated by IL-1 beta associated with LCGF, HSS and IL-1 beta. X anthine oxidase was stimulated by IL-1 beta but not with HSS and LCGF. Associated with IL-1 beta 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 prop osed.