RELATIONSHIP BETWEEN PHRENIC NERVE ACTIVITY AND VENTILATION
RELATIONSHIP BETWEEN PHRENIC NERVE ACTIVITY AND VENTILATION
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DOI：
10.1152/ajplegacy.1971.221.2.535
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发表时间：
1971-01-01
影响因子：
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通讯作者：
ELDRIDGE, FL
中科院分区：
文献类型：
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作者：
ELDRIDGE, FL
方法 体重 1.7 至 4.0 kg 的 19 只猫用戊巴比妥 (40 mg/kg ip) 或乙醚麻醉，然后静脉注射氯醛糖 (35 mg/kg) 和乌拉坦 (250 mg/kg)。将插管置于气管中。在六只猫中插入胸膜内插管并通过应变计测量压力。通过腹侧入路在颈部暴露膈神经根（通常为C1），分离、切断并缩回鞘。将近端切割端放置在双极铂电极上并浸入温热的矿物油池中。神经冲动通过具有 100 和 1,000 Hz 低频和高频截止频率的交流放大器放大，在示波器上观察并记录在磁带上。在两只猫中，膈神经的单纤维或多纤维制剂与整个神经根同时被记录，而在另外两个例子中，神经的微小（但多纤维）细枝与整个神经一起被记录。潮气量通过连接到气管插管的微型克罗肺活量计来测量。通过水银应变计转换体积、放大并记录。在少数情况下，体积是通过呼吸速度描记器的综合输出来确定的。在初次记录平静呼吸后，通过重新呼吸到肺活量计中产生的高碳酸血症和低氧刺激，获得大范围的潮气量。在某些情况下，低于正常呼吸水平的潮气量是通过首先使动物过度换气至呼吸暂停并记录恢复时的小呼吸来获得的。总共进行了 54 次再呼吸实验。在七只猫身上进行的研究也是在切断颈部的两条迷走神经后进行的。研究人员对两只猫进行了研究，逐渐增加戊巴比妥的剂量，直至潮气量下降且吸气持续时间大大延长。为了消除
METHODSNineteen cats weighing from 1.7 to 4.0 kg were anesthe-tized with pentobarbital(40 mg/kg ip) or with ether and then intravenous chloralose (35 mg/kg) and urethane (250 mg/kg). A cannula was placed in the trachea. In six cats an intrapleural cannula was inserted and pressures were measured by means of a strain gauge. A phrenic nerve root (usually C,) was exposed in the neck by ventral approach, isolated, cut, and the sheath retracted. The proximal cut end was placed on bipolar platinum electrodes and immersed in a pool of warmed mineral oil. Nerve impulses were amplified by means of an ac amplifier with 100 and 1,000 Hz low-and high-frequency cutoffs, viewed on an oscilloscope and recorded on magnetic tape. In two cats single-or paucifiber preparations of the phrenic nerve were recorded simultaneously with the whole nerve root, and in two other instances tiny (but multifiber) twigs of nerve were recorded along with the whole nerve. Tidal volumes were measured by means of a miniature Krogh spirometer attached to the tracheal cannula. Volumes were transduced by means of a mercury strain gauge, amplified, and recorded. In a few instances, volumes were determined by means of the integrated output of a pneumotachograph. A large range of tidal volumes was obtained by hypercapnic and hypoxic stimulation produced by re-breathing into the spirometer after initial recording of eupneic breathing. In some cases tidal volumes below the eupneic level were obtained by first hyperventilating the animal to the point of apnea and recording the small breaths on recovery. A total of 54 rebreathing experirnents was performed. In seven cats studies were also obtained after cutting both vagus nerves in the neck. Two cats were studied during a progressive increase in the dose of pento-barbital to the point where tidal volume was depressed and inspiratory duration greatly prolonged. In order to elimi-