Hepatotoxicity and lipid metabolism—III: Changes in phosphatidylcholine and phosphatidylethanolamine during hepatic injury caused by carbon tetrachloride

Abstract

The concentration and composition of hepatic phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were compared in rats treated with carbon tetrachloride (CCl 4) and in control rats. Administration of CCl 4 brought about a decrease in concentration of total phospholipids, PC and PE in the liver. However, the percentage concentration of PE was increased and that of PC decreased, resulting in an elevation of the PE:PC ratio after CCl 4 treatment. The fatty acid composition of PC and PE was altered by CCl 4; arachidonic and docosahexaenoic acids were decreased (the latter in PC only) and oleic and linoleic acids were increased. Stearic acid was also increased at the expense of palmitic acid. Similar changes were observed at the 1- and 2-positions as well as in four molecular species of these phospholipids. There were no significant changes in the percentage of molecular species of PC and PE, except for a considerable increase in the monoenoic fraction. These alterations were more prominent in the females than in males, and in the livers of rats killed 20 hr after the dose of CCl 4 than in the livers of those killed at 6 hr. The data further confirm that the metabolism of hepatic glycerophosphatides is altered by CCl 4 treatment. However, the fatty acid compositions of triglyceride and phospholipids were altered in different ways and there was a time difference between the two glycerides in response to CCl 4.