Stereoselectivity of spinal neurotransmission: effects of baclofen enantiomer on tail-flick reflex in rats.
Spinal rats and rats with an intact neuraxis received an intrathecal injection of an enantiomer of baclofen. The R-enantiomer was 100-1000 times more potent than its antipode in inhibiting the tail-flick reflex, both in intact rats and in spinal rats. Spinalization enhanced the inhibitory effects of both enantiomers without altering their dose-response relations. The findings show that baclofen enantiomers have direct actions on stereo-selective spinal mechanisms and that spinalization fails to alter the stereo-selectivity of spinal mechanisms towards the enantiomers.
D000818:Animals; D001418:Baclofen / Q000494:pharmacology*; D003655:Decerebrate State; D007278:Injections, Spinal; D008297:Male; D008968:Molecular Conformation; D051381:Rats; D011919:Rats, Inbred Strains; D012018:Reflex / Q000187:drug effects*; D013116:Spinal Cord / Q000187:drug effects*; D013237:Stereoisomerism; D009435:Synaptic Transmission / Q000187:drug effects*; D013623:Tail
D001418:Baclofen