Reflex effects following selective stimulation of J receptors in the cat.
Reflex effects following selective stimulation of J receptors in the cat.
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猫选择性刺激 J 受体后产生反射效应。
DOI：
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发表时间：
1980
期刊：
影响因子：
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通讯作者：
A. Paintal
中科院分区：
文献类型：
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作者：
A. Anand;A. Paintal
1. 对被麻醉的猫进行的实验表明，通过肺叶的血流量增加了133% (S.E. 33%)，在10个几乎沉默的J受体中产生了平均0.75脉冲/秒（S.E. 0.3）。通过向右心房注射12 ~ 18微克/kg的苯基二胍，可产生相同的活性。这种活动引起了明显的反射效应，即呼吸暂停、快速浅呼吸和膝跳减少。2. 心包注射木卡因阻断心脏受体活动后，研究了J受体的反射效应。这是必要的，因为左心房注射苯二胍产生反射呼吸作用和抑制膝跳。3. 低氧而非高碳酸血症可减弱J受体的反射作用，当Pa、O2低于35 mmHg时，呼吸暂停消失。这是一个中心效应，因为它发生在苯二胍后J受体活性增加的情况下，并且在切断双颈神经后缺氧的影响持续存在。4. J受体唯一不变的反射效应是每次呼吸中膈脉冲的总数和平均频率的减少。呼吸暂停后吸气时间（ti）和呼气时间（te）的变化是可变的，尽管最常见的是两者都减少了。在大约一半的观察中呼吸暂停前的第一个效果是ti的减少，在另一半中是te的减少。由此得出结论，来自J受体的输入直接抑制吸气和呼气机制。5. 在一些猫中，迷走神经切开术阻断J受体的活动后，J受体产生的呼吸暂停和快速浅呼吸仍在继续，但这并没有减少J受体的减少。在其他猫身上是这样的。te的减少有时完全独立于ti的变化，即肺拉伸受体活性。6. 由此得出结论，在适度运动中，J受体必须被刺激到产生明显的呼吸反射效应和肌肉抑制的水平。
1. Experiments carried out on anaesthetized cats showed that increasing blood flow, through the lobes of a lung, by 133% (S.E. 33%) generated an average of 0.75 impulses/sec (S.E. 0.3) in ten almost silent J receptors. Equivalent activity was produced by injecting 12‐18 micrograms phenyl diguanide/kg into the right atrium. Such activity caused marked reflex effects, i.e. apnoea, rapid shallow breathing and reduction in the knee jerk. 2. The reflex effects of J receptors were studied after blocking the activity from cardiac receptors by intrapericardial injections of xylocaine. This was necessary because left atrial injections of phenyl diguanide produced reflex respiratory effects and inhibition of the knee jerk. 3. Hypoxia, but not hypercapnia, attenuated the reflex effects of J receptors, apnoea being abolished if the Pa,O2 fell below 35 mmHg. This was a central effect as it occurred in spite of increased activity of J receptors following phenyl diguanide, and effects of hypoxia persisted after cutting both carotid nerves. 4. The only invariable reflex effect of J receptors was a reduction in the total number and the average frequency of phrenic impulses in each breath. The changes in inspiratory time (ti) and expiratory time (te) following apnoea were variable although most frequently both were reduced. In about half the observations the first effect before the apnoea was a reduction in ti, in the other half it was a reduction in te. It was concluded that an input from J receptors inhibits inspiratory and expiratory mechanisms directly. 5. In some cats apnoea and rapid shallow breathing produced by J receptors continued after interrupting their activity by vagotomy and this did not diminish the reduction in ti or te; in other cats it did. The reduction in te was at times quite independent of changes in ti, i.e. pulmonary stretch receptor activity. 6. It was concluded that J receptors must be stimulated during moderate exercise to levels that produce marked respiratory reflex effects and inhibition of muscles.