Re-evaluation of lisuride pharmacology: 5-hydroxytryptamine(1A) receptor-mediated behavioral effects overlap its other properties in rats
by
Marona-Lewicka D, Kurrasch-Orbaugh DM, Selken JR, Cumbay MG, Lisnicchia JG, Nichols DE.
Department of Medicinal Chemistry and Molecular Pharmacology,
School of Pharmacy and Pharmacal Sciences,
Purdue University, West Lafayette, IN 47907, USA.
Psychopharmacology (Berl) 2002 Oct;164(1):93-107


ABSTRACT

RATIONALE. There is substantial evidence that lisuride can produce effects linked to 5-HT(1A) receptor occupancy. Nevertheless, this action has generally been ignored in the mechanism of action of lisuride, in favor of an exclusive role for dopamine receptors in considering its antiparkinsonian effects, or an exclusive role of 5-HT(2A/2C) receptor activation in hallucinogenesis. These conclusions are surprising when one considers that the potent interaction of lisuride with 5-HT(1A) receptors has been demonstrated in several different laboratories and that activation of 5-HT(1A) and 5-HT(1B) receptors can modulate dopaminergically mediated responses. OBJECTIVE. The lack of full substitution of lisuride for lysergic acid diethylamide (LSD) in drug discrimination experiments and induction of a pronounced 5-HT syndrome by this compound at relatively low doses convinced us to execute two series of experiments that might explain the primary mechanism responsible for lisuride-mediated biological effects and its paradoxical classification as a dopamine agonist in the literature. RESULTS. In drug discrimination studies, lisuride fully mimicked the 5-HT(1A) agonist LY 293284, only partially substituted for LSD and DOI, and failed to substitute for (+)-amphetamine. Lisuride produced a significant dose-related increase in flat body posture, forepaw treading, and lower-lip retraction which reflect a modulation of behavior by action at central 5-HT(1A) receptors. Only pMPPI [4-iodo-N-[2-[4-(methoxyphenyl)-1-piperazinyl]ethyl]-N-2-pyridynyl-benzamide hydrochloride], a selective 5-HT(1A) antagonist, was effective in inhibiting all 5-HT syndrome behaviors produced by lisuride, whereas pMPPI was without effect on any behavior induced by LSD. Lisuride dose dependently decreased body temperature in rats with a potency similar to that of the selective 5-HT(1A) agonist LY 293284. The hypothermic effect of lisuride was prevented by pre-injection of pMPPI, but not by ketanserin or haloperidol. CONCLUSION. We have demonstrated that the behavioral effects of low doses of lisuride are clearly mediated by stimulation of 5-HT(1A) receptors.
5-ht1a
Lisuride
Selegiline
Roxindole
Dopamine
Amineptine
Pramipexole
Nomifensine
Methylphenidate
Alpha2 adrenoreceptors
Bromocriptine in psychiatry
Bromocriptine and depression
Dopaminergics and depression
Hofmann's LSD: My Problem Child
Dopamine agonists for Parkinson's disease


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