Effects of ouabain on carotid body chemoreceptor activity in the cat.
Effects of ouabain on carotid body chemoreceptor activity in the cat.
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哇巴因对猫颈动脉体化学感受器活性的影响。
DOI：
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发表时间：
1983
期刊：
影响因子：
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通讯作者：
J. Ribeiro
中科院分区：
文献类型：
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作者：
D. McQueen;J. Ribeiro
在用戊巴比妥麻醉的猫中研究了乌巴因输注对从切开的颈动脉窦神经末梢记录的化学感受器活性的影响。哇巴因引起化学感受器放电显着增加，随后放电频率下降至接近或低于哇巴因前水平；在后期，进一步服用哇巴因没有效果。缺氧期间输注哇巴因进一步增加了化学感受器的放电，但这种作用是短暂的。颈动脉内给药哇巴因对神经节球（交感）神经切断的猫效果较差，而静脉内给药则没有观察到显着差异。静脉内给予哇巴因后，化学感受器放电峰值的剂量水平与引起心律失常所需的剂量水平相似，但颈动脉内给药后，化学感受器放电峰值的剂量约为引起心律失常剂量的40%。在哇巴因诱导的兴奋过程中，NaCN、CO2 平衡的洛克溶液和乙酰胆碱的刺激作用得到加强，多巴胺诱导的化学抑制作用也得到加强。在兴奋后时期，这些物质引起的反应减少或消失。烟碱拮抗剂美加明和抗胆碱酯酶毒扁豆碱均不影响颈动脉化学感受器对哇巴因的反应。这项研究的主要发现是哇巴因最初使颈动脉体化学感受器“敏感”，然后使它们“脱敏”。造成这些效应的最可能机制是哇巴因的 Na+-K+-ATP 酶抑制特性。
The effects of infusions of ouabain on chemoreceptor activity recorded from the peripheral end of a sectioned carotid sinus nerve were studied in cats anaesthetized with pentobarbitone. Ouabain caused a marked increase in chemoreceptor discharge followed by a decline in discharge to frequencies near or below the pre‐ouabain level; during the latter period further administration of ouabain had no effect. Infusion of ouabain during hypoxia further increased the chemoreceptor discharge, but this effect was short‐lasting. On intracarotid administration ouabain was less effective in cats with the ganglioglomerular (sympathetic) nerves cut, whereas on intravenous administration no significant difference was observed. Following intravenous administration of ouabain the chemoreceptor peak discharge occurred with dose levels similar to those needed to cause cardiac arrhythmias, but following intracarotid administration the chemoreceptor discharge peaked at doses about 40% of those causing arrhythmias. During ouabain‐induced excitation the stimulatory action of NaCN, CO2‐equilibrated Locke solution and acetylcholine was potentiated, as was the chemo‐inhibition induced by dopamine. During the post‐excitatory period the responses evoked by these substances were reduced or abolished. Neither mecamylamine, a nicotinic antagonist, nor physostigmine, an anti‐cholinesterase, affected the response of the carotid chemoreceptors to ouabain. The major finding of this study was that ouabain initially ‘sensitizes’ the carotid body chemoreceptors and then ‘desensitizes’ them. The most likely mechanism responsible for these effects is the well established Na+‐‐K+‐ATPase‐inhibiting property of ouabain.