The hypophagic effect of restraint stress in rats can be mediated by 5-HT2 receptors in the paraventricular nucleus of the hypothalamus.
Ritanserin (0.5 and 1 mg/kg) and ketanserin (2.5 mg/kg), two antagonists with high affinity for 5-HT2 receptors, attenuated restraint stress-induced hypophagia in rats. Two injections of the 5-HT2 receptor antagonist cinanserin (30 nmol/0.5 microliter) in the paraventricular nucleus of the hypothalamus completely reversed the effect of stress on food intake. (+/-)Cyanopindolol (3 and 8 mg/kg), an antagonist at 5-HT1A and 5-HT1B receptors, had no effect whereas 8-hydroxy-2-di-n-propylamino)tetralin (30-300 micrograms/kg), an agonist at 5-HT1A receptors, significantly attenuated the hypophagia. The results suggest that restraint stress-induced hypophagia is mediated by 5-HT2 receptors in the paraventricular nucleus of the hypothalamus. The potential utility of this model in anorexia nervosa is discussed.
Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy.
G
G
Grignaschi
B
B
Mantelli
R
R
Samanin
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000578:Amidines / Q000494:pharmacology; D000818:Animals; D000855:Anorexia / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology*; D000856:Anorexia Nervosa / Q000503:physiopathology; D004195:Disease Models, Animal; D005247:Feeding Behavior / Q000187:drug effects / Q000502:physiology*; D007650:Ketanserin / Q000494:pharmacology / Q000627:therapeutic use; D008297:Male; D010286:Paraventricular Hypothalamic Nucleus / Q000503:physiopathology*; D010869:Pindolol / Q000031:analogs & derivatives / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011985:Receptors, Serotonin / Q000145:classification / Q000187:drug effects / Q000502:physiology*; D012149:Restraint, Physical; D016713:Ritanserin / Q000494:pharmacology / Q000627:therapeutic use; D013312:Stress, Physiological / Q000150:complications / Q000503:physiopathology*
D000578:Amidines; D011985:Receptors, Serotonin; D016713:Ritanserin; C047975:cyanopindolol; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D007650:Ketanserin; D010869:Pindolol; C005894:xylamidine