Alterations of lipid metabolism in mice injected with endotoxin

Some alterations in lipid metabolism in mice were observed by the intraperitoneal injection of endotoxin from Salmonella typhimurium. The content of serum triglyceride increased markedly in poisoned mice 16-24 hr postintoxication. The level of free fatty acid (FFA) in the serum of endotoxin-administered mice decreased in inverse proportion to an increase in the injected dose of endotoxin. The electrophoretic analysis of the serum lipoprotein on cellulose acetate membrane showed that pre beta-lipoprotein increased markedly and that FFA fraction in the poisoned mice sera disappeared 18 hr postintoxication. The activity of hormone-sensitive lipase in adipose tissue was elevated appreciably 2 hr after injection, but decreased more significantly after 18 hr than that in fasted control mice. On the other hand, the activity of lipoprotein lipase decreased in the post-heparin serum and adipose tissue 3 hr postintoxication, and decreased significantly after 16 hr. There were no significant differences between changes in the formation of active glycerol (alpha-GP) and in the activity of alpha glycerophosphate dehydrogenase (alpha-GPDH) in the mice liver with or without administration of endotoxin, and after 16 hr levels of both hepatic alpha-GP content and alpha-GPDH activity in poisoned mice showed a tendency to be slightly lower than those in fasted control mice.