Biosynthesis of Liver Phospholipids During the Development of a Fatty Liver. ∗

Summary

1. Liver total lipids, phospho-lipid P and phospholipid synthesis has been investigated during the development of a fatty-cirrhotic liver in animals maintained on a low-fat, low-protein diet for 17 to 297 days. 2. There is an increase in the specific and relative specific activities of total liver phospholipids between the 36th and 64th days, i.e., during the development of the fatty liver. 3. Chromatography of liver phospholipids and lipid phosphorylation during the development of a fatty liver was studied in rats maintained on low protein-low fat diets. 4. A statistically significant decrease of liver lecithin and sphingomyelin occurred at end of 5 weeks of dietary regime and continued to decrease as long as the animals were maintained on the low protein diet. 5. A statistically significant decrease of phosphatidyl ethanolamine and phosphatidyl inositol occurs at the end of 9 weeks on the dietary regime. 6. A reduction of dietary protein intake for 4 weeks results in a statistically significant decrease of phosphatidyl serine, lecithin, sphingomyelin and phosphatidyl inositol in liver mitochondria. There is a progressive increase of mitochondria phosphatidic acid as the choline deficiency progresses. The role of the reduction of phosphatidic acid in the production of a fatty liver is discussed.

The authors express thanks to Dr. Theodore Snook for histological examination.