IMMUNE CELL AND CORTISOL RESPONSES TO PHYSICALLY AND PHARMACOLOGICALLY INDUCED LOWERING OF BODY CORE TEMPERATURE

In a placebo-controlled double-blind study described by Rammsayer and co-workers in this volume, we investigated the influence of decreased body core temperature (BCT) on responses of cortisol and the immune sy stem. As described in the first paper, the decrease in BCT was achieve d by: (a) exposure to ambient cold temperature of 5-degrees-C for 20 m in (CT group), or (b) application of a 5HT-1a agonist under normal tem perature conditions (5HT group). A third group serving as control was exposed to normal temperature and placebo (NT group). The decrease of BCT seen in both CT and 5HT was accompanied by an increase in cortisol . This seemed to be due to stress experience in the CT group and to th e pharmacological challenge in the 5HT group. The number of peripheral CD4+ cells was reduced in both experimental groups. This was not medi ated by decreased BCT. In the CT group the reduction of CD4+ cells sho wed no relationship to changes in cortisol. However, in the 5HT group cortisol could be demonstrated to be the mediator of changes in periph eral CD4+ cells.