title: Effect of meptazinol on neuromuscular transmission in the isolated rat phrenic nerve-diaphragm preparation.
abstract: Meptazinol has been shown to have significant effects on neuromuscular transmission in the isolated rat phrenic nerve-diaphragm preparation. The response of the preparation to indirect electrical stimulation was increased in a concentration-dependent manner by meptazinol hydrochloride 2-32 micrograms ml-1. Meptazinol 0.5-2 micrograms ml-1 antagonized the effects the tubocurarine on this preparation, and in concentrations of 1 microgram ml-1 and greater, potentiated suxamethonium. These effects were similar to those obtained with neostigmine and it was demonstrated that meptazinol had significant anti-cholinesterase activity in the concentrations used. Inhibition of cholinesterase with ecothiopate revealed a neuromuscular blocking activity of meptazinol in concentrations as low as 0.25 micrograms ml-1.
mesh_terms: D000818:Animals; D001381:Azepines / Q000494:pharmacology*; D002800:Cholinesterase Inhibitors / Q000494:pharmacology; D004357:Drug Synergism; D066298:In Vitro Techniques; D008297:Male; D008621:Meptazinol / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects; D009388:Neostigmine / Q000494:pharmacology; D009469:Neuromuscular Junction / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D013390:Succinylcholine / Q000494:pharmacology; D009435:Synaptic Transmission / Q000187:drug effects*; D014403:Tubocurarine / Q000037:antagonists & inhibitors
chemical_list: D001381:Azepines; D002800:Cholinesterase Inhibitors; D008621:Meptazinol; D009388:Neostigmine; D013390:Succinylcholine; D014403:Tubocurarine