highlighted topics Physiological and Genomic Consequences of Intermittent Hypoxia Selected Contribution: Phrenic long-term facilitation requires 5-HT receptor activation during but not following episodic hypoxia
highlighted topics Physiological and Genomic Consequences of Intermittent Hypoxia Selected Contribution: Phrenic long-term facilitation requires 5-HT receptor activation during but not following episodic hypoxia
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米切尔。选择性贡献：膈长期促进需要5-HT受体在发作性缺氧期间激活，而不是在发作性缺氧之后激活。中国生物医学工程学报（英文版）；2009 - 12。-间歇性缺氧引起呼吸运动输出的持续增强，称为长期促进（LTF）。膈肌LTF可通过5-羟色胺（5-HT）受体拮抗剂酮色胺预处理来预防。我们验证了5-HT受体激活是诱导而非维持膈LTF所必需的假设。在麻醉、迷走神经切断、麻痹和通气四组sd - dawley大鼠[1)对照组（n 5 11）， 2)酮色林预处理（2 mg/kg静脉注射；n 5 7），以及在发作性缺氧后0和45 min（各n 5 7）]，监测三次5 min的异氧缺氧（动脉P 2 5 40 6 2 Torr， 5 min高氧间隔）后1 h的峰值综合膈神经活动（* Phr）。酮色林短暂降低* Phr，但在10分钟内恢复到基线水平。发作性缺氧后1小时，对照组和缺氧后0分钟和45分钟酮色林组* Phr较基线显著升高。相反，酮色林预处理可消除膈膜LTF。我们得出结论，5-HT受体的激活是启动（缺氧期间）所必需的，但不是维持（缺氧后）膈LTF。二氧化碳压力0直肠所有实验，氨基甲酸乙酯过量。
Mitchell. Selected Contribution: Phrenic long-term facilitation requires 5-HT receptor activation during but not following episodic hypoxia. J Appl Physiol 90: 2001–2006, 2001.—Episodic hypoxia evokes a sustained augmentation of respiratory motor output known as long-term facilitation (LTF). Phrenic LTF is prevented by pretreatment with the 5-hydroxytryptamine (5-HT) receptor antagonist ketanserin. We tested the hypothesis that 5-HT receptor activation is necessary for the induction but not maintenance of phrenic LTF. Peak integrated phrenic nerve activity ( * Phr) was monitored for 1 h after three 5-min episodes of isocapnic hypoxia (arterial P O 2 5 40 6 2 Torr; 5-min hyperoxic intervals) in four groups of anesthetized, vagotomized, paralyzed, and ventilated Sprague-Dawley rats [ 1 ) control ( n 5 11), 2 ) ketanserin pretreatment (2 mg/kg iv; n 5 7), and ketanserin treatment 0 and 45 min after episodic hypoxia ( n 5 7 each)]. Ketanserin transiently decreased * Phr, but it returned to baseline levels within 10 min. One hour after episodic hypoxia, * Phr was significantly elevated from baseline in control and in the 0- and 45-min posthypoxia ketanserin groups. Conversely, ketanserin pretreatment abolished phrenic LTF. We conclude that 5-HT receptor activation is necessary to initiate (during hypoxia) but not maintain (following hypoxia) phrenic LTF. CO 2 pres- sures O Rectal of all experi- ments, urethane overdose.