PBG-synthetase activity in the liver of Yoshida sarcoma-bearing rats.

The etiology of anemia in cancer is not fully understood. A possible cause of the anemia of tumor-bearing animals could be a decreased activity in the enzymes of the heme-pathway. We report the enzyme activity of porphobilinogen-synthetase in the liver of Yoshida sarcoma-bearing rats. PBG-synthetase activity in the whole liver, is higher in tumor-bearing rats than in controls, although the enzyme activity by a gram of wet liver is decreased. Hence PBG-synthetase activity is not a limiting factor in the biosynthesis of heme in tumor-bearing animals.