BIOLOGICAL EVALUATION OF SOME BIPHENYL ANALOGS OF ACETYL-SECO-HEMICHOLINIUM NO 3

  • 1 January 1977
    • journal article
    • research article
    • Vol. 229  (2) , 276-286
Abstract
The O atoms in the esteratic moiety of acetyl-seco-hemicholinium No. 3 (AcHC-3) were replaced with C to form the ether, ketone and aliphatic analogs. The thio and acetylthio-seco analogs of hemicholinium No. 3 (HC-3) were studied. When evaluated in the rabbit sciatic nerve-gastrocnemius muscular preparation all analogs caused neuromuscular blockades in 2 or 3 separate phases. The 1st phase of blockade caused by the ketone and thio analogs was rapid in onset and reversed by neostigmine. It was presumably competitive in type. The 1st phase of blockade caused by the ether and aliphatic analogs was increased by neostigmine and was probably of the non-competitive type. All analogs caused a 2nd phase of blockade that was reversed by choline and was typical of HC-3. A 3rd blockade was found following the ether and ketone analogs. All analogs were more active as inhibitors of the true and pseudocholinesterases than was HC-3. All analogs were much less potent as inhibitors of acetylcholine synthesis than was AcHC-3.