Actions of a new muscle relaxant (AH8165) on neuromuscular transmission.
The effects of a new muscle relaxant, AH8165, on miniature endplate potential (MEPP) amplitude and frequency, endplate sensitivity to acetylcholine, and muscle twitch tension were studied in vitro in the frog sartorius muscle. Nerve terminal effects were studied in vivo in the cat soleus muscle and its ventral root fibers. AH8165 stimulates the nerve terminal, as evidenced by increased MEPP frequency and the appearance of post-drug repetitive activity. In the same concentration range at which MEPP frequency is increased, MEPP amplitude, endplate sensitivity to acetylcholine, and twitch tension are decreased. This suggests that AH8165 produces muscle relaxation by blocking postsynaptic cholinergic receptors. (Key works: Neuromuscular relaxants, AH8165.).
D000109:Acetylcholine / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D001001:Anura; D001391:Azo Compounds / Q000494:pharmacology*; D002415:Cats; D055598:Chemical Phenomena; D002621:Chemistry; D006168:Guinea Pigs; D007093:Imidazoles / Q000494:pharmacology; D066298:In Vitro Techniques; D007478:Iontophoresis; D008564:Membrane Potentials / Q000187:drug effects; D008722:Methods; D009119:Muscle Contraction / Q000187:drug effects; D009466:Neuromuscular Blocking Agents / Q000009:adverse effects; D009469:Neuromuscular Junction / Q000187:drug effects; D003473:Neuromuscular Nondepolarizing Agents / Q000494:pharmacology*; D011726:Pyridinium Compounds / Q000494:pharmacology*; D011950:Receptors, Cholinergic; D012584:Sciatic Nerve / Q000187:drug effects; D013268:Stimulation, Chemical; D009435:Synaptic Transmission / Q000187:drug effects*
D001391:Azo Compounds; D007093:Imidazoles; D009466:Neuromuscular Blocking Agents; D003473:Neuromuscular Nondepolarizing Agents; D011726:Pyridinium Compounds; D011950:Receptors, Cholinergic; D000109:Acetylcholine