ACTIVATION OF HEPATIC GLUTAMINASE IN THE ENDOTOXIN-TREATED RAT

The basis for the accelerated hepatic utilization of glutamine that oc curs during endotoxemia was investigated. In rats treated with Escheri chia coli lipopolysaccharide, glutaminase activity, measured in membra nes of freezed-thawed liver mitochondria, was unchanged compared with that of controls. However, flux through glutaminase in intact mitochon dria was increased more than 3.5-fold by the endotoxin treatment. The effect was associated with an increase in the sensitivity of glutamina se flux to phosphate, an activator of the enzyme. These findings are s imilar to the activation of glutaminase by glucogenic hormones. We, th erefore, propose that the increased hepatic consumption of glutamine d uring endotoxemia is due to an activation of glutaminase that is only evident in intact mitochondria. (C) 1995 Academic Press, Inc.