RESUMO
This study was performed on rats receiving nitrosamine precursors, as potent liver carcinogens, in order to investigate and follow up the porphyrin metabolism during intaking hepatocarcinogens. As clarified from our results, progressive increase in free erythrocyte porphyrins, erythrocyte protoporphyrin, haem content and hepatic total porphyrins were observed after 2 months intaking these carcinogens and further increases were gradually elevated in parallel with continued receiving these chemicals which was extended to 7 months.At the same time, such elevations were also observed in the activity of hepatic 5- aminolevulinic acid [ALA] - synthetase and uroporphyrinogen-1-synthetase either in hepatic tissue or erythrocyte of these carcinogen subjected rats.However significant inhibition was found in the activity of erythrocyte ALA- dehydrase which was reached to 40.5% of the control values after 7 months.Therefors, these observations demonstrate that intaking hepatocarcinogens may influence the rate of hepatic porphyrin and haem biosynthesis