ACUTE AND LONG-TERM EFFECTS OF STRESSORS ON PULMONARY IMMUNE FUNCTIONS

To study the effects of different types or intensities of stressors on immune reactivity in the lungs, we studied the ex vivo production of nitric oxide (NO) and IL-1 beta by alveolar macrophages (AM) after sho rt exposure of rats to restraint stress or inescapable electric footsh ocks. Exposure to electric footshocks of various intensities resulted in an intensity-dependent decrease in NO production whereas the IL-1 b eta production by AM had increased. The secretory activity was similar ly affected by restraint stress. When the time course of electric foot shocks on secretory functions of AM was studied, it was found that the effects on NO and IL-1 beta production by AM were normalized 3 days a fter the stress induction, but reappeared when cells were isolated 1 t o 2 wk after stress exposure. Analysis of the effects of electric foot shocks of various intensities on antibody production 10 days after the stress session and subsequent lung immunization with trinitrophenyl c onjugated keyhole limpet hemocyanin (TNP-KLH), showed a footshock inte nsity-dependent response. Although exposure to stress induced an incre ase in plasma levels of adrenocorticotropic hormone (ACTH) and cortico sterone (CORT), hormone levels did not differ between the various stre ss-exposed groups. This suggests that the observed stress effects on p ulmonary immune functions were not mediated by ACTH or CORT but point to a direct involvement of the autonomic nervous system.