Pulmonary hypertension alters blood flow distribution and impairs the hyperemic response in the rat diaphragm.
Pulmonary hypertension alters blood flow distribution and impairs the hyperemic response in the rat diaphragm.
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DOI：
10.3389/fphys.2023.1281715
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发表时间：
2023
影响因子：
4
通讯作者：
中科院分区：
文献类型：
--
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肺动脉高压（PH）的特征是肺血管重构、呼吸肌和心脏损伤以及运动不耐受。具体而言，受损的气体交换增加了隔膜的工作;然而，受损的收缩功能使隔膜无法满足PH中慢性过度通气的增加的代谢需求。鉴于肌肉收缩功能部分取决于足够的血流量（），呼吸功能障碍可能是由于无法使氧气输送与氧气需求相匹配。我们假设PH大鼠与健康对照组相比，对收缩的充血反应降低。 方法：将SD大鼠随机分为正常对照组（HC组，n = 7）和PH组（PH组，n = 7）。PH大鼠给予野百合碱（MCT），而HC大鼠给予溶剂。通过超声心动图监测疾病进展。区域和总隔膜血流量和血管传导率在基线和3分钟的电刺激收缩期间，使用荧光微球。 结果：PH大鼠显示出疾病的形态学和超声心动图标准（即，加速时间/射血时间、右心室肥大）。在所有大鼠中，总肋膈在收缩过程中增加，组间无差异。在HC大鼠中，与PH大鼠相比，内侧肋的增加更大（55% ± 3%对44% ± 4%，p < 0.05），PH大鼠表现出向腹侧肋区域的再分布。 结论：这些研究结果支持了局部膈肌灌注的重新分配和PH中受损的内侧肋充血反应，表明PH改变了膈肌血管功能和氧输送，为PH诱导的膈肌收缩功能障碍提供了潜在机制。
Pulmonary hypertension (PH) is characterized by pulmonary vascular remodeling, respiratory muscle and cardiac impairments, and exercise intolerance. Specifically, impaired gas exchange increases work of the diaphragm; however, compromised contractile function precludes the diaphragm from meeting the increased metabolic demand of chronic hyperventilation in PH. Given that muscle contractile function is in part, dependent upon adequate blood flow (), diaphragmatic dysfunction may be predicated by an inability to match oxygen delivery with oxygen demand. We hypothesized that PH rats would demonstrate a decreased hyperemic response to contractions compared to healthy controls. Methods: Sprague-Dawley rats were randomized into healthy (HC, n = 7) or PH (n = 7) groups. PH rats were administered monocrotaline (MCT) while HC rats received vehicle. Disease progression was monitored via echocardiography. Regional and total diaphragm blood flow and vascular conductance at baseline and during 3 min of electrically-stimulated contractions were determined using fluorescent microspheres. Results: PH rats displayed morphometric and echocardiographic criteria for disease (i.e., acceleration time/ejection time, right ventricular hypertrophy). In all rats, total costal diaphragm increased during contractions and did not differ between groups. In HC rats, there was a greater increase in medial costal compared to PH rats (55% ± 3% vs. 44% ± 4%, p < 0.05), who demonstrated a redistribution of to the ventral costal region. Conclusion: These findings support a redistribution of regional diaphragm perfusion and an impaired medial costal hyperemic response in PH, suggesting that PH alters diaphragm vascular function and oxygen delivery, providing a potential mechanism for PH-induced diaphragm contractile dysfunction.
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影响因子：
3.7
作者：
Himori K;Abe M;Tatebayashi D;Lee J;Westerblad H;Lanner JT;Yamada T
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影响因子：
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作者：
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DOI：
10.1152/ajpregu.00358.2016
发表时间：
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影响因子：
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作者：
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影响因子：
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作者：
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