Posted by jrbecker on April 1, 2006, at 22:15:41
In reply to Re: melatonin, REM, Parkinson's disease, posted by zeugma on March 30, 2006, at 21:13:30
>Eur Neuropsychopharmacol. 2006 Mar 6; [Epub ahead of print] Links
Melatonin affects the immobility time of rats in the forced swim test: The role of serotonin neurotransmission.Micale V, Arezzi A, Rampello L, Drago F.
Department of Experimental and Clinical Pharmacology, University of Catania, Catania, Italy.
The efficacy of melatonin or its derivatives in depressive patients has been recently considered for clinical application. However, the evidence for its effect on experimental models of depression is not consolidated. Here, the effects of melatonin on the model of forced swim test (FST) paradigm were studied in male rats of the Wistar strain after acute intraperitoneal (i.p.) administration of 0.1, 0.5 or 1 mg/kg of the hormone. Melatonin at doses of 0.5 and 1 mg/kg, but not of 0.1 mg/kg, decreased the immobility of rats in the FST paradigm suggesting a possible antidepressant-like activity. The dose of 0.5 mg/kg appeared to be as potent as clomipramine 50 mg/kg in reducing the immobility time of rats in the FST paradigm. The effect of melatonin on immobility time of rats in the FST paradigm was abolished by the simultaneous injection of the non-selective melatonin antagonist, luzindole (0.25 mg/kg, subcutaneously). Similarly, administration of small quantities of serotonin (5-HT, 5 ng/1 mul) or of the 5-HT(2A)/5-HT(2C) receptor agonist 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (2 ng/1 mul) injected into the amygdale totally suppressed the reduction of immobility time in the FST paradigm induced by melatonin 0.5 mg/kg. These results may suggest that effects of melatonin on the behavioral reaction of rats in the FST paradigm are due to an interaction of the hormone with central 5-HT neurotransmission.
PMID: 16527463 [PubMed - as supplied by publisher]
poster:jrbecker
thread:626219
URL: http://www.dr-bob.org/babble/20060329/msgs/627649.html