Muller N, Bryan A C, Zamel N
J Appl Physiol Respir Environ Exerc Physiol. 1980 Nov;49(5):869-74. doi: 10.1152/jappl.1980.49.5.869.
We studied the change in tonic activity of the inspiratory muscles during acute hyperinflation. Hyperinflation was provoked in two asthmatic and three normal subjects by progressively doubling doses of histamine. Changes in lung volume were determined with magnetometers and with a body plethysmograph. Intercostal muscle activity was recorded with surface electrodes and diaphragmatic activity with esophageal electrodes. Tonic activity was defined as electrical activity in the electromyogram present at end expiration. After histamine the maximal observed increase in plethysmographic thoracic gas volume in the five subjects was 29.8 +/- 6.4% of control (mean +/- SE). Hyperinflation was accompanied by a significant increase in tonic activity of the intercostal muscles (P < 0.01) and the diaphragm (P < 0.01). There was a significant correlation between the increase in thoracic gas volume and the increase in tonic intercostal (r = 0.82, P = 0.003) and diaphragmatic (r = 0.89, P = 0.003) activity. We conclude that histamine-induced hyperinflation is accompanied by persistent inspiratory muscle activity throughout expiration.
我们研究了急性肺过度充气期间吸气肌紧张性活动的变化。通过逐步将组胺剂量加倍，在两名哮喘患者和三名正常受试者中诱发肺过度充气。用磁力计和体容积描记器测定肺容积变化。用表面电极记录肋间肌活动，用食管电极记录膈肌活动。紧张性活动定义为呼气末肌电图中的电活动。给予组胺后，五名受试者中观察到的肺容积描记胸廓气体容积最大增加量为对照值的29.8±6.4%（平均值±标准误）。肺过度充气伴随着肋间肌（P<0.01）和膈肌（P<0.01）紧张性活动的显著增加。胸廓气体容积增加与肋间肌（r=0.82，P=0.003）和膈肌（r=0.89，P=0.003）紧张性活动增加之间存在显著相关性。我们得出结论，组胺诱导的肺过度充气在整个呼气过程中伴随着持续的吸气肌活动。
