Effect of an auditory stress on peritoneal and alveolar cells in C57BL/6J mice of advanced age

The aim of this study was to analyse the effects of auditory stress on peri toneal and alveolar macrophages in C57 BL/6J mice of advanced age, and to c ompare the results to those obtained in old mice submitted to a sham stress , and to those observed in young mice submitted to the same auditory stress . We used a chemiluminescence assay to measure the production of free oxyge n radicals (FOR) by macrophages. Eight 22 month-old mice were exposed to a sound stress of 110 dB for three consecutive nights; nine were submitted to a sham stress. The results were compared to those obtained in young (8 wee k-old) mice, 21 submitted to noise stress, and 17 controls. The corticoster one level was not increased after stress in any group. FOR production in ol d mice was significantly higher than that in young mice. Stress did not ind uce significant changes in FOR production by alveolar cells in young mice; however, the FOR production by alveolar cells was significantly higher in t he stressed group than in the control group of old mice. These results show that noise stress is associated with modifications of macrophage functions that are influenced by cell localization, the behaviour of alveolar and pe ritoneal macrophages of old mice being clearly different in our experimenta l model. Copyright (C) 2000 John Wiley & Sons, Ltd.