Disparities in the respiratory burst between human and rat neutrophils

The importance of reactive oxygen species (ROS) in neutrophil (PMN)-mediate d injury to host tissues has been strongly implicated in a number of animal models. Peculiarities of the laboratory rat PMN, including an apparent pau city of superoxide release, prompted us to examine disparities hi the respi ratory burst between human and rat PMNs. Using isolated PMNs, we examined o xygen consumption, superoxide release, nitrate/nitrite release, and dihydro rhodamine (DHR) oxidation in response to an array of soluble stimuli. Our f indings confirm that intact rat PMNs release Little superoxide in compariso n to human PMNs when primed and activated by soluble stimuli, For example, PMA-activated human PMNs released superoxide at 10.1 +/- 2.7 times the rate of rat PMNs (P < 0,01), However, measurements of oxygen consumption, cell- associated oxidant production (by DHR oxidation) and release of superoxide from electroporated cells suggests that rat PMNs generate oxidants at rates equivalent to human PMNs but preferentially release them in an intracellul ar compartment, Implications for the study of PMN-mediated oxidant injury i n animal models are discussed.