Trippenbach T, Kelly G
J Appl Physiol Respir Environ Exerc Physiol. 1983 Feb;54(2):496-501. doi: 10.1152/jappl.1983.54.2.496.
The effects of airway occlusions at functional residual capacity (FRC) on both "integrated" phrenic activity (Phr) and intercostal muscle electromyogram (intEMG) were studied in intact and vagotomized spontaneously breathing kittens during the 1st wk of life. Animals were anesthetized im with a mixture of ketamine (30 mg/kg) and acepromazine (1.1 mg/kg). In the intact kittens, inspiratory loading led to a significant increase in peak amplitudes of both Phr and intEMG and prolongation of inspiratory (TI) and expiratory (TE) times. Mean values of rate of rise of Phr and intEMG measured at 200 ms (intEMG200) from the onset of inspiration were unaffected. The results indicated that in newborns the vagal component of the load compensation is of great importance. Following vagotomy, airway occlusion produced a significant increase in mean values of TI and intEMG only. These small but significant changes suggest that most of the load compensation reflex is dependent on prolongation of TI. Increased intEMG200 during loading in the vagotomized kittens, observed during several trials, implies that the intercostal fusion-alpha interaction may operate in newborns.
在出生后第一周，对完整的和切断迷走神经的自主呼吸小猫，研究了功能残气量（FRC）时气道阻塞对“整合”膈神经活动（Phr）和肋间肌肌电图（intEMG）的影响。动物通过肌肉注射氯胺酮（30mg/kg）和乙酰丙嗪（1.1mg/kg）的混合物进行麻醉。在完整的小猫中，吸气负荷导致Phr和intEMG的峰值幅度显著增加，吸气时间（TI）和呼气时间（TE）延长。从吸气开始在200ms时测量的Phr和intEMG的上升速率平均值不受影响。结果表明，在新生儿中，负荷补偿的迷走神经成分非常重要。切断迷走神经后，气道阻塞仅使TI和intEMG的平均值显著增加。这些微小但显著的变化表明，大部分负荷补偿反射依赖于TI的延长。在几次试验中观察到，切断迷走神经的小猫在负荷时intEMG200增加，这意味着肋间融合-α相互作用可能在新生儿中起作用。
