Effects of chronic mild stress (CMS) and imipramine administration, on spleen mononuclear cell proliferative response, serum corticosterone level andbrain norepinephrine content in male mice

There is increasing evidence that stress and emotional reactions produce ch anges in various immune processes. These changes may be due to alterations of the stress responses endocrine and for autonomic mediating mechanisms. I n order to study such effects, the impact of chronic mild stress (CMS) appl ication, and of subsequent imipramine administration were studied on the sp leen mononuclear cell proliferative response period. OF1 strain male mice w ere subjected to 4 or 7 weeks of CMS. The effects of these treatments on se rum corticosterone levels and hypothalamic and hippocampal norepinephrine ( NE) contents were also assessed. Subjects submitted to CMS had a higher spl een mononuclear cell proliferative response after either treatment duration . Imipramine treatment diminished this response enhancement in CMS exposed animals, but did not alter the proliferative responses of control subjects. Serum corticosterone levels, as well as hypothalamic and hippocampal norep inephrine contents did not significantly vary between groups. Taken togethe r, these results suggest that CMSs effects on immune reactivity are not rel ated to serum glucocorticoids or NE changes in these locations associated w ith the hypothalamic-pituitary-adrenocortical (HPA) axis. (C) 1999 Elsevier Science Ltd. All rights reserved.