SYNTHESIS OF CREATOL, A HYDROXYL RADICAL ADDUCT OF CREATININE AND ITSINCREASE BY PUROMYCIN AMINONUCLEOSIDE IN ISOLATED RAT HEPATOCYTES

Creatol is a hydroxyl radical adduct of creatinine and the precursor o f methylguanidine (MG), a uremic toxin. We investigate the synthesis o f creatol and MG from creatinine and the effect of substances that aff ect the hydroxyl radical in isolated rat hepatocytes. In the presence of increasing concentrations of creatinine, rising level of creatol we re found after 2 h incubation in Krebs-Henseleit bicarbonate buffer. H owever, further increase of creatol was not observed after 4 and 6 h i ncubations. On the other hand, MG after 2 h incubation achieved a leve l of about 50% that of creatol and increased depending on both the cre atinine concentration and the incubation period. DMSO, a hydroxyl radi cal scavenger decreased the generation of creatol and MG by about 50% at 2.5 mM and the inhibition depended on DMSO concentration. Puromycin aminonucleoside (PAN) increased both by about 170%. These findings de monstrated that hepatocytes synthesize creatol prior to MG and are inh ibited by a hydroxyl radical scavenger. They also show that PAN increa sed hydroxyl radical generation in tissue cells.