Department of Clinical Physiology, Health Sciences, Tohoku University Graduate School of Medicine, Miyagi, Japan.
Allergol Int. 2011 Sep;60(3):365-72. doi: 10.2332/allergolint.10-OA-0266. Epub 2011 May 25.
Although oxitropium bromide is used clinically as an anticholinergic drug (i.e., parasympathetic antagonist) to relax airway smooth muscle, we examined whether it has or does not have any effects on diaphragm muscle.
Three treatment sets, an oxitropium bromide inhalation only group, an oxitropium bromide inhalation plus endotoxin injection group (in vivo) and an oxitropium bromide incubation group (in vitro) were studied as to diaphragm muscle contractile properties.
Oxitropium bromide inhalation shifted force-frequency curves upward at 2 h after inhalation (p < 0.05) and inhibited the decrease of force-frequency curves due to endotoxin injection in vivo. Incubation with oxitropium bromide of untreated diaphragm muscle and diaphragm muscle injected with endotoxin did not increase the force-frequency curves dose-dependently in vitro; however, it caused both types of muscle to be fatigue resistant.
We speculate that the increment of muscle contractility with the inhalation of oxitropium bromide was induced by the antagonization of musucarinic acetylcholine receptors (mAChR). In addition, the changes of fatigue resistance provoked by oxitropium bromide, which also is speculated to antagonize mAChR, may be beneficial in the treatment of patients with COPD.
尽管溴化氧托品临床上被用作一种抗胆堿能药物（即副交感神经拮抗剂）来松弛气道平滑肌，但我们研究了它是否对膈肌肌肉有任何作用。
我们研究了三组处理，即溴化氧托品吸入组、溴化氧托品吸入加内毒素注射组（体内）和溴化氧托品孵育组（体外），以研究膈肌肌肉收缩特性。
溴化氧托品吸入后 2 小时，吸入组的力频曲线向上移动（p < 0.05），并抑制了体内内毒素注射引起的力频曲线下降。体外孵育未处理的膈肌肌肉和注入内毒素的膈肌肌肉与溴化氧托品孵育，不会使力频曲线呈剂量依赖性增加；然而，它使这两种类型的肌肉都具有抗疲劳性。
我们推测，溴化氧托品吸入引起的肌肉收缩力增加是通过拮抗毒蕈堿型乙酰胆堿受体（mAChR）引起的。此外，溴化氧托品引起的抗疲劳性变化也可能拮抗 mAChR，这对 COPD 患者的治疗可能有益。
