Effects of riboflavin deficiency on the lipids of rat liver.

Newly weaned male rats were maintained on a riboflavin-free diet for 5 weeks, and a study was made on the effect of the deficiency upon liver lipids. The content of glyceride in the livers varied among the deficient rats. High contents of glyceride were demonstrated in one-third of the deficient rats, whereas the similar level as that of control was shown in the remaining deficient rats. Contents of phospholipids and relative amounts of individual phospholipids were not altered significantly by the deficiency. Riboflavin deficiency exerted effects on fatty acid components of liver lipids. The composition of fatty acids of triglycerides varied in the deficient rats depending on the content of glycerides. However trends of increase in linoleic acid and decrease in palmitic acid towards fatty liver were observed in the deficiency in comparison with the control. On the other hand, the changes in phospholipid fatty acids were similar in all deficient rats, and the increase in linoleic acid and the decrease in arachidonic acid were brought about by the deficiency compared with controls, respectively. In liver homogenates, the incorporation of 14C-palmitate into triglycerides was higher in the deficient rats irrespective of the presence or absence of fluorde but incorporation into phospholipids was slightly lower in the deficient rats than in control animals.