EFFECTS OF FETAL ALCOHOL EXPOSURE ON FEVER, SICKNESS BEHAVIOR, AND PITUITARY-ADRENAL ACTIVATION-INDUCED BY INTERLEUKIN-1-BETA IN YOUNG-ADULT RATS

Exposure to alcohol in utero can lead to long-lasting impairments of i mmune functions and to decreased resistance to infectious agents. We h ave previously reported that fetal alcohol-exposed rats show markedly decreased lipopolysaccharide-induced fever and suggested that fetal al cohol exposure (FAE) impairs the communication between the immune and the nervous systems. The present study examined the effects of interle ukin-1 beta (IL-1) on body temperature, motor activity, ingestive beha vior, and pituitary-adrenal activation in fetal alcohol-exposed and co ntrol rats. Transmitters for continuous biotelemetric recording of bod y temperature and motor activity were implanted ip in normal (N) adult rats, offspring of dams fed a liquid diet supplemented with ethanol ( E), and pair-fed control offspring (P). In one experiment, rats were i njected with either IL-I (2 mu g/kg, ip) or saline at the beginning of the light period. IL-1 produced a marked increase in body temperature , which was significantly lower in E rats than in N and P rats. In a s econd experiment, rats were administered either IL-1 (10 mu g/kg, ip) or saline at the beginning of the dark period. IL-I produced an initia l transient hypothermia followed by a longer-lasting hyperthermia. Dur ing the hyperthermic phase, fever in the E rats was lower than in the P rats, but comparable to fever in the N rats. IL-1 significantly redu ced motor activity, during both the hypothermic and hyperthermic phase s. This effect was similar in all prenatal treatment groups. IL-1 also suppressed 24-h food consumption in N and P rats and water consumptio n in P rats, but it did not produce significant anorexia and adypsia i n E rats. A third experiment demonstrated that IL-1 (2 mu g/ kg, ip) s ignificantly increased ACTH and corticosterone release in all prenatal treatment groups. IL-l-induced corticosterone secretion was attenuate d in P offspring, compared to both E and N rats. Together, these findi ngs indicate that exposure to ethanol in utero produces impairments in mechanisms that mediate the effects of IL-1 on body temperature (part icularly during the light period) and ingestive behavior, but not on m otor activity and pituitary-adrenal activation. In view of the adaptiv e role of IL-l-induced fever and anorexia, these impairments may contr ibute to the decreased resistance to infections observed in animals an d humans following FAE. (C) 1996 Academic Press, Inc.