EVIDENCE THAT BRIEF STRESS MAY INDUCE THE ACUTE-PHASE RESPONSE IN RATS

Exposing rats to a single session of inescapable tail shock (IS) reduc es corticosteroid binding globulin (CBG) 24 h later (Fleshner et al., Endocrinology 136: 5336-5342, 1995). The present experiments examined whether reductions in CBG are differentially affected by controllable vs. identical uncontrollable tail shock, are mediated by IS-induced gl ucocorticoid elevation, or reflect IS-induced activation of the acute phase response and whether IS produces fever. The results demonstrate that 1) equivalent reductions in CBG are observed in response to escap able tail shock or yoked IS, 2) IS-induced CBG reduction is not blocke d by adrenalectomy in rats that receive basal corticosteroid replaceme nt or by pretreatment with RU-38486, and 3) IS appears to activate the acute phase response, since IS reduces serum levels of an acute-phase negative reactant (CBG), increases serum levels of acute-phase positi ve reactants (haptoglobin and alpha(1)-acid glycoprotein), and increas es core body temperature 20-24 h later.