EFFECTS ON VARIOUS TYPES OF LIVER CATALASE BY GROWTH OF RHODAMINE SARCOMA AND BY ADMINISTRATION OF IN VIVO CATALASE-DEPRESSING SUBSTANCE PREPARED FROM THE TUMOR

Catalase extracted from the liver of normal rats with the aid of Triton X-100 was distinguished into several types having different isoleectric points (pI) by isoelectric fractionation with Ampholine carrier ampholytes devised by Vesterberg and Svensson.16) Of these types, four types were dominant in relative activity; "acidic" catalases had isoelectric points at 5.90 and 6.08, and "neutral" ones at 6.75 and 6.90±0.04 at 0-1°. The total activity of liver catalase decreased as Rhodamine sarcoma grew on the back of a rat; the activity of pI 5.90-catalase first decreased significantly, then followed by a decrease of the activity of pI 6.08-catalase, whereas the activity of neutral catalases rather increased until the ratio in wet weight of tumor to whole body reached approximately 20%. At higher ratios, the neutral catalases also decreased. Catalase extracted from the liver of normal mice in the same way as from the liver of normal rats was also distinguished into several types, of which six major catalases had isoelectric points at 6.33, 6.40, 6.47, 6.53, 6.68, and 6.78±0.02 at 0-1°. When in vivo catalase-depressing substance prepared from Rhodamine sarcoma was injected into mice, the total catalase activity decreased; "acidic" catalases (pI 6.33-6.53) markedly decreased in activity, while "neutral" catalases (pI 6.74-7.08), which were little or not present in the liver of the control mice, increased in activity. Administration of the substance at any doses tested did not cause decrease in the activity of neutral catalases. The dual changes of the acidic and neutral catalases by growth of the tumor was possibly caused by two different causes, one of which could be in vivo catalasedepressing substance produced by the tumor.