Changes in glutathione peroxidase activities and the oxidative burst of leukocytes during inflammation in the mouse and rat.

The relationship between glutathione peroxidase (GSH-Px) activity and opsonized zymosan-induced chemiluminescence (CL) has been studied with exudate leukocytes obtained at different times after induction of inflammatory responses in the mouse peritoneal cavity with heat-killed Corynebacterium parvum and in the rat pleural cavity with lambda-carrageenin. GSH-Px activity in mouse peritoneal exudate cells fell markedly after 2-4 h, returning to normal within 1-2 days. The lowered enzyme activity was associated with an increased ability of the cells to generate CL. Rat pleural exudate cells exhibited a slight fall in GSH-Px activity after 6 h which increased to supranormal levels within 1-2 days. During this period the ability of the cells to generate CL continually increased. The data indicate that during the early phase of increased generation of reactive oxygen species (ROS) by inflammatory leukocytes, the intracellular protective mechanism, represented by GSH-Px, is compromised. Subsequently, GSH-Px activity increases to or above initial levels possibly due to the presence of mononuclear cells and/or as a response to the increased generation of ROS.