Abstract |
beta-Eudesmol, a sesquiterpenol extracted from a Chinese herb, Atractylodes lancea, at 10-80 microM, did not affect muscle action potentials, miniature and evoked endplate potentials and acetylcholine-induced depolarization in the presence or absence of neostigmine in mouse phrenic nerve-diaphragms. However, the tetanic fade, muscle fasciculation and twitch potentiation induced by neostigmine were effectively antagonized by 20 microM beta-eudesmol. When trains of pulses were applied to the nerve in the presence of neostigmine, beta-eudesmol reduced the incidence of explosive depolarization of the endplate from 95% to 35-67% of junctions, and shortened the duration when it occurred. Moreover, both the maximal and steady-state depolarizations during repetitive stimulation were reduced while the amplitudes of steady-state endplate potentials were increased. The results suggest that beta-eudesmol antagonized neostigmine-induced neuromuscular failure mainly by a presynaptic action to depress the regenerative release of acetylcholine during repetitive stimulation. The mechanism of antagonism is obviously not tubocurarine-like and it is unrelated to desensitization of acetylcholine channels.
|
Authors | L C Chiou, C C Chang |
Journal | European journal of pharmacology
(Eur J Pharmacol)
Vol. 216
Issue 2
Pg. 199-206
(Jun 05 1992)
ISSN: 0014-2999 [Print] Netherlands |
PMID | 1397007
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
|
Chemical References |
- Drugs, Chinese Herbal
- Neuromuscular Blocking Agents
- Sesquiterpenes, Eudesmane
- Terpenes
- Neostigmine
- beta-eudesmol
- Acetylcholine
|
Topics |
- Acetylcholine
(pharmacology)
- Action Potentials
(drug effects)
- Animals
- Diaphragm
(drug effects, innervation)
- Drug Interactions
- Drugs, Chinese Herbal
(pharmacology)
- Electric Stimulation
- Female
- Male
- Mice
- Mice, Inbred ICR
- Muscle Contraction
(drug effects)
- Neostigmine
(pharmacology)
- Neuromuscular Blocking Agents
(pharmacology)
- Sesquiterpenes, Eudesmane
- Terpenes
(pharmacology)
|