Effects of mescaline and some of its analogs on cholinergic neuromuscular transmission.
Mescaline (3,4,5-trimethoxyphenylethylamine; MES) and its analogs, anhalinine (ANH) and methylenemescaline trimer (MMT) were investigated, using sciatic-sartorius preparations of the frog and cortical tissue from the rat. The effects of MES and its analogs were examined with respect to muscle twitch, resting membrane potential and nicotinic receptor binding. Mescaline and its analogs (10-100 microM) blocked both directly and neurally evoked twitches but their effects on neurally evoked twitches were greater than those on directly evoked twitches. Mescaline, ANH and MMT decreased amplitude of the miniature endplate and endplate potentials, decreased acetylcholine (ACh) quantal content, hyperpolarized the resting membrane potential and prolonged duration of the action potential. They did not significantly displace the binding of [125I]-alpha-bungarotoxin (alpha-BTX) to nicotinic receptors, at concentrations which blocked neuromuscular transmission. These results suggest that MES and its analogs inhibit cholinergic neuromuscular transmission by blocking release of ACh; they also affect K+ conductance.
Department of Pharmacology, Meharry Medical College, Nashville, TN 37208.
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Ghansah
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Kopsombut
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Malleque
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Brossi
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D004558:Electric Stimulation; D066298:In Vitro Techniques; D007546:Isoquinolines / Q000494:pharmacology; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D008635:Mescaline / Q000031:analogs & derivatives / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects; D009132:Muscles / Q000166:cytology / Q000187:drug effects; D009469:Neuromuscular Junction / Q000187:drug effects*; D010275:Parasympathetic Nervous System / Q000187:drug effects*; D011896:Rana temporaria; D051381:Rats; D017207:Rats, Sprague-Dawley; D011978:Receptors, Nicotinic / Q000187:drug effects; D012584:Sciatic Nerve / Q000187:drug effects; D013329:Structure-Activity Relationship; D009435:Synaptic Transmission / Q000187:drug effects*; D014227:Triazines / Q000494:pharmacology
D007546:Isoquinolines; D011978:Receptors, Nicotinic; D014227:Triazines; C080167:methylenemescaline trimer; C080166:anhalinine; D000109:Acetylcholine; D008635:Mescaline