Blocking effects of a new component, paeoniflorigenone, in paeony root on neuromuscular junctions of frogs and mice.
A new monoterpene, paeoniflorigenone (PFG) (100-900 micrograms/ml), which was isolated from paeony roots and identified chemically, suppressed both indirectly and directly stimulated muscle twitchings of frog sciatic nerve-sartorius muscle preparation, and it indirectly stimulated muscle twitchings of phrenic nerve-diaphragm muscle preparations. The suppression effect by PFG (300 micrograms/ml) on twitching was not reversed by neostigmine (60 micrograms/ml) and was restored by washing out of PFG. PFG (150 micrograms/ml) depolarized the diaphragm muscle membranes by 10 mV and did not change the electrotonic potentials. PFG (100 micrograms/ml) inhibited weakly acetylcholine (5 micrograms/ml)-induced slow contractions. These results demonstrated that PFG is a depolarizing neuromuscular blocking agent, being similar to succinylcholine, except that PFG did not produce any contraction, but succinylcholine did.
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D039821:Monoterpenes; D009119:Muscle Contraction / Q000187:drug effects; D009388:Neostigmine / Q000494:pharmacology; D009466:Neuromuscular Blocking Agents / Q000494:pharmacology*; D010791:Phrenic Nerve / Q000187:drug effects; D011898:Ranidae; D012584:Sciatic Nerve / Q000187:drug effects; D013390:Succinylcholine / Q000494:pharmacology; D013729:Terpenes / Q000494:pharmacology*; D014403:Tubocurarine / Q000494:pharmacology
D039821:Monoterpenes; D009466:Neuromuscular Blocking Agents; D013729:Terpenes; D009388:Neostigmine; C042713:paeoniflorigenone; D013390:Succinylcholine; D000109:Acetylcholine; D014403:Tubocurarine