Effects of agents increasing serotonin transmission on the increase of dopamine metabolism caused by morphine in the rat nucleus accumbens.
The effect of subcutaneous injection of 10 mg/kg morphine on homovanillic acid (HVA) concentrations in the nucleus accumbens was studied in rats which had received d-fenfluramine, a serotonin releaser, or m-chlorophenylpiperazine, a serotonin agonist, before morphine. 2.5 mg/kg d-fenfluramine or m-chlorophenylpiperazine had no effect on HVA in the nucleus accumbens but significantly reduced the rise in HVA induced by morphine. None of the drugs modified the levels of morphine in the rat brain. The results suggest that agents increasing serotonin transmission inhibit the effect of morphine on dopamine neurons innervating the nucleus accumbens.
D000818:Animals; D004298:Dopamine / Q000378:metabolism; D005277:Fenfluramine / Q000494:pharmacology*; D006719:Homovanillic Acid / Q000378:metabolism*; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009714:Nucleus Accumbens / Q000378:metabolism*; D010648:Phenylacetates / Q000378:metabolism*; D010879:Piperazines / Q000494:pharmacology*; D051381:Rats; D012686:Septal Nuclei / Q000378:metabolism*; D012701:Serotonin / Q000502:physiology*
D010648:Phenylacetates; D010879:Piperazines; D005277:Fenfluramine; D012701:Serotonin; D009020:Morphine; C015068:1-(3-chlorophenyl)piperazine; D004298:Dopamine; D006719:Homovanillic Acid