Toxicological Studies on the Yellowed Rice by P. islandicum Sopp. III

Abstract

Our toxicological researches made plain, as previously reported, that the yellowed rice inoculated with P. islandicum Sopp is capable of inducing acute and subacute liver injuries and chronic diseases like liver cirrhosis and might possibly cause malignant hepatoma. With the aim, therefore, to ascertain whether the hepatoma can be induced or not, since 1957 we have fed 3 groups of rats, 30 each, though 3 in A group, 8 in B group and 4 in C group still survive as of the 650th day. The following results have so far been obtained. 1. In A group fed with the moldy rice only, the primary hepatic carcinoma was found in the rats dying on 548th and 553rd day. In these cases, though no metastasis was found in other organs than the liver, there were observed the infiltration of the hepatoma cells into the capsule of liver or the intrahepatic metastasis, i.e. the thrombus of hepatoma cells. Moreover the sarcomatous tumor was found in the liver of 3 cases dying on 548th, 569th, and 622nd day. 2. Beside the above hepatoma, were found in the most cases, as usually observed hitherto, the fibrosis, the proliferation of small bile ducts including cholangiofibrosis and the nodular hyperplasia of liver cells, except the liver cirrhosis. 3. In B group fed with the DAB-added moldy rice and in C group with DAB without the moldy rice, 11 cases and 6 cases each had the primary hepatic carcinoma to die between 248th-379th day in the former and between 356th-396th day in the latter, indicating that the moldy rice is capable of shortening the lifetime in case of DAB only. The metastasis of the hepatic carcinoma was found in the lung artery of one case of B group. Moreover the sarcoma was observed to concur with the hepatic carcinoma on the case each of the both groups.