The effect of ambient temperature on rectal temperature, food intake and short term body weight in the capsaicin desensitized rat
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.Subcutaneous injections of capsaicin (mean cumulative dose: 80.1±3.6 mg·kg−1) permanently reduced the capacity of rats to withstand a hot environment when deprived of water. With water available, hyperthermia was discrete or absent in capsaicinized rats in hot environment.
Desensitization was followed by a significant decrease in both food intake and body weight. Treated rats recovered normal body weight after 3 weeks.
In a hot environment, compared to controls, food intake was significantly increased in capsaicin desensitized rats which maintained their body weight. In cold environment, food intake was decreased in capsaicin desensitized rats which lost body weight. At normal ambient temperature, food intake and body weight were similar in the 2 groups.
Caloric intake adjustment at high and at low temperatures was therefore disturbed in capsaicin desensitized rats. It is concluded that hypothalamic thermodetectors implicated in both thermoregulation and food intake behaviour could be partially damaged by capsaicin.
Key wordsTemperature regulation Capsaicin Food intake Body weight
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- Cabanac M (1970) Interaction of cold and warm temperature signals in the brain stem. In: Hardy JD, Pharo Gagge A, Stolwijk JAJ (eds) Physiological and behavioral temperature regulation, Courtesy of Charles C. Thomas Pub, Springfield Ill, chap 37Google Scholar
- Cabanac M (1972) Thermoregulatory behaviour. In: Bligh J, Moore R (eds) Essays on temperature regulation. North Holland Publishing Co, Amsterdam, p 19Google Scholar
- Cabanac M (1979) Le comportement thermorégulateur. J Physiol (Paris) 75:115–178Google Scholar
- Cabanac M, Cormareche-Leydier M, Poirier JL (1976) The effect of capsaicin on temperature regulation of the rat. Pflügers Arch 366:217–221Google Scholar
- Gasnier A, Mayer AR (1939) Recherches sur la régulation de la nutrition du lapin domestique. Ann Physiol Physico Chim Biol 15:186–194Google Scholar
- Hamilton CL, Brobeck JR (1966) Food intake and activity of rats with rostral hypothalamic lesions. Proc Soc Exp Biol Med 122: 270–272Google Scholar
- Jancsó-Gabor A, Szolcsányi J, Jancsó N (1970a) Irreversible impairment of thermoregulation induced by capsaicin and similar pungent substances in rats and guinea-pigs. J Physiol (Lond) 206:495–507Google Scholar
- Jancsó-Gabor A, Szolcsányi J, Jancsó N (1970b) Stimulation and desensitization of the hypothalamic heat sensitive structures by capsaicin in rats. J Physiol (Lond) 208:449–459Google Scholar
- Lipton JM (1968) Effect of preoptic lesions on heat escape responding and colonic temperature in the rat. Physiol Behav 3:165Google Scholar
- Roberts WW, Mooney, RD (1974) Brain areas controlling thermoregulatory grooming, prone extension, locomotion and tail vasodilatation in rats. J Comp Physiol Psychol 86:470–481Google Scholar
- Rudiger W, Seyer G (1965) Lateralisation of cortico hypothalamic relations as revelated by thermosensitive behaviour in the rat. Physiol Bohemoslov 14:515–522Google Scholar
- Rudiger W, Seyer G (1968) Thermosensitive bar-pressing behavior of the rat with unilateral lesion in the hypothalamus and during cortical spreading depression. Acta Biol Exp 28:375–382Google Scholar
- Satinoff E, Hendersen R (1977) Thermoregulatory behavior. In: Honig WK, Staddon JER (eds) Handbook of operant behavior. Prentice-Hall, Inc. Englewood CliffsGoogle Scholar
- Szolcsányi J, Jóo F, Jancsó-Gábor A (1971) Mitochondrial changes in preoptic neurons after capsaicin desensitization of the hypothalamic thermodetectors in rats. Nature 229:116–117Google Scholar
- Szolcsányi J, Jancsó-Gábor A (1975) Analysis of the role of warmth detectors by means of capsaicin under different conditions. In: Temperature regulation and drug action. Proc Symp, Paris 1974, Karger, Basel p. 331Google Scholar