1. Statistically significant positive correlation was recognized between the mortalities from liver cirrhosis and the mean annual temperatures in the prefectures of Japan. In the countries of the world significant correlation was present only in the countries of mean annual temperature below 16°C.
2. Rats were fed with a choline-deficient diet without cystine at temperature of 7°C and 22°C. On a high fat diet, the liver fat content of the rats which were kept at 7°C was significantly less than that of the rats which were kept at 22°C.
At lower temperature food and protein intake increased. The prevention of deposition of liver fat was not observed in the rats which were kept at 7°C, when their protein intake was decreased to the same level as that of the rats which were kept at 22°C. Hence the prevention of deposition of liver fat at lower temperature seemed to be due to the increased protein intake.
3. The liver fat content of the mice which were fed with a cholinedeficient diet with added cystine at temperature of 6°C, 13°C, 19°C, and 26°C increased markedly. No regular relationship between liver fat content and environmental temperature was observed in these animals.
4. The influence of nutrition on the production of liver cirrhosis due to carbon tetrachloride was investigated. With the administration of carbon tetrachloride liver collagen content increased significantly and serum albumin concentration decreased significantly. Protein, choline, and α-tocopherol had no influences on the changes of liver collagen content and serum protein. On a low protein diet fibrosis of the liver which was estimated histologically was reduced by the supplement of α-tocopherol, but not influenced by the addition of choline. Fibrosis of the liver of the rats which were fed with a high protein diet was more advanced than that of the rats which were fed with the low protein diet.
