The effects of injections of bombesin into the cerebral ventricles on food intake and body temperature in food-deprived rats.

Central injections of bombesin have been shown to produce hypothermia in animals exposed to a cold environment, but not in animals maintained under thermoneutral conditions. Peripheral injections have been associated with decreased food intake in rats. The data reported here demonstrate a significant, dose-related decrease in both body temperature and food intake following microinjections of bombesin into the cerebral ventricles of male rats maintained at reduced body weight. All measurements of food intake and body temperature were recorded at an ambient temperature of 23 +/- 1 degrees C. The bombesin-induced hypothermia, but not the hypophagia, was partially reversed by prior subcutaneous injections of naloxone. Microinjections of bombesin failed to produce a decrease in body temperature in satiated rats.