Effects of triiodothyronine on the 5-hydroxytryptophan-induced head twitch and its potentiation by antidepressants in mice.
Daily injection of triiodothyronine (T3) for 3 consecutive days dose dependently enhanced 1-5-HTP (4 mg/kg)-induced head twitches in mice. This effect was blocked by 1-penbutolol. Pretreatment with a sub-effective dose of T3 (0.06 mg/kg) markedly enhanced the ability of clenbuterol but not indalpine to potentiate the response to 1-5-HTP. Likewise, the effects of T3 were more pronounced on the desipramine- or maprotiline-induced potentiation of head-twitches than on the action of citalopram or clomipramine. These data suggest that the increased responsiveness to 1-5-HTP caused by T3 involves an indirect (noradrenalin-mediated) rather than a direct effect on serotonergic processes.
D006916:5-Hydroxytryptophan / Q000494:pharmacology*; D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology*; D002976:Clenbuterol / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D006257:Head; D008297:Male; D051379:Mice; D009068:Movement / Q000187:drug effects*; D010880:Piperidines / Q000494:pharmacology; D014202:Tremor / Q000139:chemically induced; D014284:Triiodothyronine / Q000494:pharmacology*
D000928:Antidepressive Agents; D010880:Piperidines; D014284:Triiodothyronine; D006916:5-Hydroxytryptophan; C018181:indalpine; D002976:Clenbuterol