Effect of Endotoxin on Pyruvate Kinase Activity

The pyruvate kinase (PK) activity of mouse liver increases after injection of endotoxin. It decreases in animals given cortisone alone and remains essentially unchanged in those given cortisone and endotoxin at the same time. CCl4 causes an increase in liver PK activity, but neither it nor endotoxin changes the activity of muscle PK. Addition of octonoate to liver homogenates inhibits the activity of liver PK. These results suggest that the rapid depletion in liver glycogen after administration of endotoxin or CCl4 may be related to increased PK activity. Induction of tolerance does not prevent the increase in liver PK activity in challenged animals.