Inhibitory regulations of ohmefentanyl and morphine on postsynaptic dopamine receptors
Abstract
Ohmefentanyl, a highly selective agonist for u opioid receptors, produced a naloxone-reversible inhibition of amphetamine-induced ipsilateral and apomorphine-induced contralateral rotation in rats with 6-hydroxy-dopamine-induced unilateral lesion of nigrostriatal neurons. Acute treatments of ohmefentanyl and morphine decreased dopamine receptor density and inhibited the enhanced binding of [3H]spiperone to rat striatal dopamine receptors induced by denervation. It is proposed that these two drugs probably have an indirect inhibitory effect on postsynaptic dopamine receptors in rat striatum.
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