The role of acetylcholine in tetraethylammonium induced contractures of the chick biventer cervicis muscle in the presence of lidocaine.
Lidocaine (0.92 mM) potentiated tetraethylammonium (TEA, 0.6-6 mM) induced contractures of the chick biventer cervicis muscle (BVC) in vitro. The dose ratio for TEA (EC50 in lidocaine/EC50 control) was 1.16 X 10(-3). Lidocaine (0.92 mM) blocked nerve and muscle action potentials in the BVC preparation, blocked slow fibre MEPPS, and blocked indirectly elicited muscle contraction. Lidocaine (0.92 mM) non-competitively blocked acetylcholine (ACh) induced contractures of the chick BVC. Gallamine competitively blocked ACh contractures (pA2 6.53) but produced only a relatively weak non-competitive block of TEA induced contractures in lidocaine. TEA induced contractures of the chick BVC in the presence of lidocaine probably do not involve ACh.
D000109:Acetylcholine / Q000037:antagonists & inhibitors / Q000502:physiology*; D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002645:Chickens; D004558:Electric Stimulation; D005703:Gallamine Triethiodide / Q000494:pharmacology; D066298:In Vitro Techniques; D008012:Lidocaine / Q000494:pharmacology*; D009045:Motor Endplate / Q000187:drug effects; D009119:Muscle Contraction / Q000187:drug effects*; D019789:Tetraethylammonium; D013757:Tetraethylammonium Compounds / Q000494:pharmacology*
D013757:Tetraethylammonium Compounds; D019789:Tetraethylammonium; D008012:Lidocaine; D000109:Acetylcholine; D005703:Gallamine Triethiodide