DIETARY RESTRICTION MODIFIES FEVER RESPONSE IN AGING RATS

Intermittent (every-other-day) feeding initiated at 19 months of age a nd continued for 12 weeks, led to a moderate decrease in body weight o f aging rats, enhanced survival and modified diurnal changes in body t emperature and fever response to bacterial endotoxin (E. coli lipopoly saccharide, LPS). Diet-restricted animals which survived LPS administr ation, displayed reduced febrile response, i.e. (i) a moderate hypothe rmia in an early phase, and (ii) a delayed onset of body temperature e levation, as compared with their ad libitum-fed controls. However, pea k body temperature values were similar in both groups. The rats of bot h groups which did not develop hyperthermia in response to LPS, died w ithin 24 h of LPS administration. In control, but not in diet-restrict ed rats, Variations in body weight during the 12 weeks prior LPS admin istration may be predictable in regard to their survival after LPS tre atment. It seems that the resistance to bacterial endotoxin in aging r ats is associated with their ability to develop hyperthermia. Copyrigh t (C) 1997 Elsevier Science Ireland Ltd.