A comparison of the potencies of a series of barbiturates at the neuromuscular junction and on the central nervous system.
The ability of a series of barbiturates to depress the depolarizing action of carbachol at the end-plate of guinea-pig lumbrical muscle was studied. The compounds studied were: amorbarbital, aprobarbital, barbital, barbituric acid, butabarbital, butalbital, dimethylbutylethyl barbituric acid, hexobarbital, mephobarbitak, secobarbital, thiamylal, and thiopental. The depressant activity was sensitive to small changes in structure of the compounds strongly suggesting that a specific receptor site was involved in the interaction of the drug with the tissue. The observed relative potencies on the motor end-plate were compared with their anesthetic potencies assayed on tadpoles. The two potencies went hand-in-hand for all the compounds studied, including the convulsant member of the series.
D000818:Animals; D001463:Barbiturates / Q000494:pharmacology*; D002217:Carbachol / Q000037:antagonists & inhibitors; D002490:Central Nervous System / Q000187:drug effects*; D003864:Depression, Chemical; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007814:Larva; D009119:Muscle Contraction / Q000187:drug effects; D009132:Muscles / Q000187:drug effects; D009469:Neuromuscular Junction / Q000187:drug effects*
D001463:Barbiturates; D002217:Carbachol