DISSOCIATION OF TEMPERATURE-CHANGES AND ANOREXIA AFTER EXPERIMENTAL COLITIS AND LPS ADMINISTRATION IN RATS

The acute phase of inflammation induces both anorexia and fever. Becau se several analyses suggest a linkage between the meal size and body t emperature, we assessed whether temperature changes were causal to ano rexia in situations involving acute inflammation. Specifically, we eva luated whether elevations of body temperature could account for the re duced food intake after induction of experimental colitis [via intrare ctal infusions of trinitrobenzene sulfonic acid (TNB)] or injection of 100 mu g/kg lipopolysaccharide (LPS). Temperature was monitored telem etrically in rats via implanted temperature transmitters. TNB-treated rats demonstrated a 5-day anorexia that resulted specifically from a d ecrease in meal size. Although TNB-treated rats were hypothermic on th e day of treatment, no other body temperature changes were noted. LPS reduced food intake and elevated temperature, but these two effects we re uncorrelated temporally. Although these results do not identify the mechanisms of anorexia, the findings indicate dearly that the anorexi a associated with the acute inflammatory response is not secondary to fever.