Sex differences in the respiratory response to hemorrhage in the conscious, New Zealand white rabbit.
Sex differences in the respiratory response to hemorrhage in the conscious, New Zealand white rabbit.
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新西兰白兔意识清醒时对出血的呼吸反应的性别差异。
DOI：
10.1152/ajpregu.00494.2006
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Schadt,JamesC
中科院分区：
文献类型：
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作者：
Strittmatter,RachelR;Schadt,JamesC
在清醒的动物中，对出血的反应是双相的。在第1阶段，动脉压维持不变，第2阶段以严重低血压为特征。尽管有类似的作用，但对意识清醒的动物对失血的综合心血管和呼吸反应知之甚少。我们评估了出血期间的心肺变化，以检验以下假设：1）呼吸频率（RR）和血气在第1阶段没有变化;2）RR在第2阶段增加; 3）男性和女性出血期间的RR和血气变化相似。我们测量了16只清醒、长期准备的雄性和雌性新西兰白色家兔出血期间的平均动脉压、RR和血气。我们移除静脉血，直至平均动脉压≤40 mmHg。性别不影响出血时的平均动脉压、心率、PaO 2、PaCO 2或pH值，也不影响诱导第2阶段所需的失血量。PaCO 2在第1和第2阶段分别从37 ± 1降至33 ± 1和29 ± 1 mmHg（P< 0.001）。出血前PaO 2为87 ± 2 mmHg。PaO 2在第一阶段无变化（92 ± 2 mmHg），但在第二阶段升高（101 ± 2 mmHg;P< 0.001）。体温、PvCO 2（胸腔静脉）和通气-灌注不匹配（A-a梯度）在第1和第2阶段无变化。在第1阶段，两种性别均未增加RR。男性RR在第2阶段增加一倍，而女性RR无明显变化（P> 0.001）。因此，虽然PaCO 2在第1和第2阶段降低，但在两个阶段和两种性别中，降低的方式不同。
In conscious animals, the response to hemorrhage is biphasic. Duringphase 1, arterial pressure is maintained.Phase 2is characterized by profound hypotension. Despite allied roles, less is known about the integrated cardiovascular and respiratory response to blood loss in conscious animals. We evaluated cardiorespiratory changes during hemorrhage to test the hypotheses that1) respiratory rate (RR) and blood gases do not change duringphase 1;2) RR increases duringphase 2; and3) RR and blood gas changes during hemorrhage are similar in males and females. We measured mean arterial pressure, RR, and blood gases during hemorrhage in 16 conscious, chronically prepared, male and female New Zealand white rabbits. We removed venous blood until mean arterial pressure was ≤40 mmHg. Sex did not affect mean arterial pressure, heart rate, PaO2, PaCO2, or pH during hemorrhage or the blood loss required to inducephase 2. PaCO2decreased significantly from 37 ± 1 to 33 ± 1 and 29 ± 1 mmHg (P< 0.001) duringphase 1and2, respectively. Before hemorrhage, PaO2was 87 ± 2 mmHg. PaO2was unchanged inphase 1(92 ± 2 mmHg) but increased inphase 2(101 ± 2 mmHg;P< 0.001). Body temperature, PvCO2(thoracic vena cava), and ventilation-perfusion mismatch (A-a gradient) were unchanged duringphases 1and2. Neither sex increased RR duringphase 1. While males doubled RR duringphase 2, RR in females did not change (P< 0.001). Thus, while PaCO2decreases inphase 1andphase 2, the decreases are achieved in different ways across the two phases and in the two sexes.