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随着温度升高,动脉pH值的降低不会受到 (Rhinella marina) 和 (Python molurus) 的高氧的影响
Samanta Aparecida Castro1,2, Cléo Alcantara Costa Leite2, Tobias Wang1
1Zoophysiology, Aarhus University, 8000 Aarhus C, Denmark.
The Journal of experimental biology
|November 27, 2023
概括
爬行动物和两动物的动脉pH调节是复杂的. 这项研究发现,增加的氧气水平并没有改变和蛇的呼吸驱动与温度上升,挑战现有的假设.
科学领域:
- 生理学 生理学 生理学
- 比较生理学比较生理学
- 阳热生物学 阳热生物学
背景情况:
- 湿热生物的动脉pH值随着温度的升高而下降,这与动脉二氧化碳 (PCO2) 的升高有关.
- 阿尔法斯塔特假设表明这种pH值变化是由于通风管调节蛋白质电离,但实验数据显示pH值下降的幅度小于由histidine imidazole pKa变化预测的幅度.
- 驱动这些生理变化的精确调节机制仍在争论中.
研究的目的:
- 研究氧气介导呼吸驱动器在调节 (Rhinella marina) 和蛇 (Python molurus) 在不同温度下调节动脉pH的作用.
- 为了测试这种假设,高氧会增加氧气介导的驱动力,在更高的温度下更显著地呼吸,从而影响动脉PCO2和pH.
主要方法:
- 和蛇在不同的适应温度下 (的20°C和30°C,蛇的25°C和35°C) 暴露于过氧 (氧气水平升高).
- 在高氧化条件下测量了动脉PCO2水平,以评估呼吸驱动的变化.
- 动脉pH值与温度和PCO2变化相关的监测.
主要成果:
- 在类动物中,高氧会在20°C和30°C时引起动脉PCO2的类似增加,这表明温度独立的氧气介导呼吸反应.
- 在蛇中,高氧症在25°C或35°C时没有显著影响动脉PCO2,这表明在测试温度范围内,这种物种缺乏氧气介导的呼吸调节.
- 这些结果表明,氧气介导的呼吸驱动力不会随着这些外热生物的体温升高而增加.
结论:
- 这些发现不支持这样的假设,即增加氧气介导的呼吸驱动力有助于在和蛇的较高温度下观察到的动脉pH值下降.
- 替代性或额外的调节机制可能控制这些外热脊椎动物的温度,动脉PCO2和pH之间的关系.
- 需要进一步的研究来阐明控制爬行动物和两动物在不同热条件下的酸平衡因素的复杂相互作用.
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