AUDITORY STRESS INDUCES CHANGES IN MEMBRANE FUNCTIONS OF MOUSE PERITONEAL-MACROPHAGES

Stressful events induce responses in the endocrine and immune systems. The authors analysed the influence of repetitive noise stress on peri toneal macrophage oxidative and phagocytic responses. Plasma corticost erone levels were also measured. Different groups of 6- to 8-week-old C57BL/6 male mice were exposed for 1 night (n = 14) and 3 nights (n = 21) to a sound stress of 110 dB in an audiogenic stress chamber. Contr ol animals were submitted to a sham stress for 1 night (n = 13) and 3 nights (n = 17). A marked decrease was observed in the phagocytic resp onse to yeast (P = 3 x 10(-4)) while a mild increase in the oxidative response stimulated by opsonized zymosan was noted only after the 3 ni ght stress (P = 0.02). Corticosterone levels of control and stressed m ice did not differ. These results indicate that the stress resulting f rom repetitive noise causes modifications in peritoneal macrophage act ivity, and that these changes are dependant on the duration of stress. These functional alterations seem more complex than a simple general suppression or activation.