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

Abstract

Since 1951 we have been engaging in the joint research on the toxicology of the yellowed rice polluted by P. islandicum Sopp. Long term feedings of animals with the moldy rice and the fungus mat as well as a series of chemical studies on the toxic substances gave us the following results. 1. It is concluded from the data of feeding experiments on mice and rats that symptoms, body weights, survival days, and fatality are a series of toxicological response, since they are to continuously move from the case of larger doses in shorter days to that of smaller doses in longer days. Thus the P. islandicum Sopp growing rice grains have surely a toxic effect on the mice and rats even when they are fed with a satisfactory nutrition, though the effect is unknown in lesser dose than 1% moldy rice grains administered in their whole life. 2. Pathological damages observed are mainly acute liver injury and liver cirrhosis; the acute injury is centrolobular necrosis in feature and can be classified into three types of liver atrophy, acute, subacute, and subchronic, occurring on the early stage of feeding, while the liver cirrhosis is divided into two types of postcollapse cirrhosis and portal liver cirrhosis, occurring on the early and later stages. 3. Acute liver injuries are related to the dose, period of administration and animals' susceptibility, with high rate of occurrence as a whole. According to the data of moldy rice, liver cirrhosis is easily developed through acute liver injury, and it is considerable in the individual variation regarding the dose and susceptibility, with high rate of occurrence as a whole. 4. As the findings related to the liver cirrhosis, nodular hyperplasia of liver, cholangiofibrosis and pleomorphism of liver cell are noticed. 5. As the findings on other organs than liver, pancreas, degenerative changes in brain, and depositions of calcium-like substance in kidney, heart muscles, and blood vessels are observed. 6. As the results of the chemical researches, we obtain the conclusion that there exist Luteoskyrin and chlorine containing peptide, two kinds of toxic substances, representing the toxicity of P. islandicum Sopp in the penicillium growing rice grains as in the fungus mat.