FORMATION OF NITRIC-OXIDE BY RAT AND HAMSTER ALVEOLAR MACROPHAGES - AN INTERSTRAIN AND INTERSPECIES COMPARISON

Nitric oxide (NO) plays an important role in non-specific host defense , which can be recognized by its antimicrobial and cytotoxic activity against pathogens. However, there appear to exist interspecies differe nces in the ability of macrophages to generate NO. The object of this study was to determine whether there exist intraspecies differences in the production of NO. We compared NO formation by alveolar macrophage s (AM) from five different rat strains (Sprague-Dawley, Wistar, Lewis, Fisher, and Brown Norway), two different stocks of Syrian Golden hams ters, and one stock of Chinese hamsters. The AM were harvested by bron choalveolar lavage and stimulated in vitro with various concentrations of LPS and/or IFN-gamma. The oxidation product of NO, nitrite, was me asured in the AM supernatant by the Griess reaction. Upon stimulation with LPS and/or IFN-gamma, AM from all five rat strains were able to r elease NO, but the amount of NO produced differed significantly among the rat strains. However, none of the stimuli was able to induce AM fr om the two stocks of Syrian Golden hamsters as well as AM from the sto ck of Chinese hamsters to release measurable amounts of NO. These find ings point to distinct regulatory mechanisms of the NO pathway in AM f rom different species and to variations of this mechanism in the AM fr om the investigated rat strains. (C) 1998 Elsevier Science Ireland Ltd . All rights reserved.