A Long-Term Nutritional Study with Autoxidized Oil

Abstract

In the previous paper, authors reported that triglyceride content in the liver of rat given orally autoxidized methyl linoleate increased 18 h after the administration of the oxidized ester, but during these periods, no change was observed in the activities of the enzymes such as α-glycerophosphate dehydrogenase and triglyceride synthetase related with lipid synthesis in the liver. One of the purposes of this experiment is to examine whether the same phenomenon observed in the previous experiment occures among the mice fed on autoxidized safflower oil for long time. Commercial stock diet, 10g per mouse are fed as basal diet to one of the three groups each consisting of 50 mice. Mice in other two groups recieved 0.1 ml of fresh or autoxidized safflower oil per mouse by mixing each with 10g of the basal diet, respectively. Feedings were continued for 9 months and observnation was performed on growth rate and mortality during this period. Five mice of each group were killed at 2, 9, 14, 30 and 39 weeks after the start of feeding to determine blood glucose level, hepatic triglyceride and cholesterol contents and activities of various enzymes in liver. The following results were obtained : 1. The autoxidized oil obviously caused the lowerimg of average gain of the body weights of mice of the group fed this oil as compared with other two groups fed on basal diet or with fresh oil. 2. At the time when the lowering of body weight gain was observed, the mortalities of the mice of this group became higher than those of other two groups. 3. The glucose levels in bloods, triglyceride and cholesterol contents to livers did not show any difference among three test groups fed on basal diet, with fresh oil and with oxidized oil. 4. In the present experimetal conditions, no clear difference in tested enzyme activities in livers of mice was observed among the three test groups mentioned above.