Impairment of thermoregulation, food and water intakes in the rat after hypothalamic injections of 5,6-dihydroxytryptamine.
A bilateral microinjection into the anterior hypothalamus of 5,6-dihydroxytryptamin (5,6-DHT), a substance that lesions serotonin (5-HT)-containing neurons, caused a rise in the body temperature of the rat. The anatomical sites were the same as those at which 5-HT given in the same dose range (1.25-2.5 mug) evoked a similar hyperthermia. When exposed for one hour to a temperature of either 35 degrees C or 8 degrees C, the rats were not able to defend against the heat or cold, respectively. The magnitude of this thermoregulatory deficit depended upon the dose of 5,6-DHT given as well as the site of injection. A partial recovery from the warmth deficit was evident 13-17 days following the 5,6-DHT microinjection. Food and water intakes were also suppressed significantly and body weights declined concomitantly. These results provide additional evidence to support the view that a serotonergic mechanism in the hypothalamus is involved in both thermoregulation and the control of ingestive behavior.
D015115:5,6-Dihydroxytryptamine / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001833:Body Temperature Regulation / Q000187:drug effects*; D001835:Body Weight / Q000187:drug effects; D004327:Drinking Behavior / Q000187:drug effects*; D005247:Feeding Behavior / Q000187:drug effects*; D005334:Fever / Q000139:chemically induced; D007031:Hypothalamus / Q000187:drug effects; D008297:Male; D008845:Microinjections; D051381:Rats; D012701:Serotonin / Q000494:pharmacology; D014363:Tryptamines / Q000494:pharmacology*
D014363:Tryptamines; D012701:Serotonin; D015115:5,6-Dihydroxytryptamine