an α-Bungarotoxin neuronal nicotinic receptor antagonist with selective nanomolar affinity for a subtype of neuronal nAChR in the brain that probably incorporates the Alpha7 subunit‚ compared with micromolar affinity at muscle nAChR and at α-Bungarotoxin insensitive neuronal nAChR.

C₁₉-norditerpenoid alkaloid C₃₇H₅₀N₂O₁₀.HClO₄ derivative of Methyllycaconitine from plants of the Delphinium genus‚ Ranunculaceae.

medium-lasting myorelaxing activity; as a tertiary amine‚ Methyllycaconitine (MLA) crosses histohematic barriers and is active orally: blockage of Nicotinic cholinoreceptors of striated muscles at 2.5-3.5 mg/kg intravenously and 30-40 mg/kg orally; MLA relates to the non-depolarizing competitive myorelaxing agents‚ and its antagonists are Galanthamine and Neostigmine.
0.5-2 mg/kg intravenously‚ has an hypotensive activity due to the inhibition of nervous influx transmission in sympathetic and parasympathetic ganglia.
MLA acts directly on the brain and spinal cord; enhances the amplitude of monosynaptic potentials in inhibiting the Nicotinic receptors of Renshaw cells; removes totally the inhibiting effect of Nicotine on spinal cord monosynaptic responses; intravenously in cats‚ MLA has been shown to interact with brain Nicotinic receptors‚ eliminating variations of EEG caused by subecholine; recent studies (see attached sheet) show that MLA and some related diterpenoid alkaloids act as neuronal α-Bungarotoxin sensitive brain nicotinic receptors antagonist.

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