Hypoxic conditions, in addition to effects on the CO2 and O2 transport, may have an impact on various functions of red blood cells (RBCs) including ion and metabolic regulation, oxidative stress induction, and transport of nitrites, ammonia, urea, etc. We used laser diffraction, spectrometry, and flow cytometry for evaluation of responses of RBCs of lower vertebrates and human RBCs to hypoosmotic conditions, ammonia, and oxidative stress in normoxia and hypoxia. Under hypoosmotic conditions RBCs of lower vertebrates swell and immediately initiate the regulatory volume decrease (RVD) reaction. In our experiments, the RVD reaction in RBCs of Carassius carassius and Rana temporaria was inhibited by hypoxic conditions and restored by reoxygenation. Transport of ammonia/ammonium in human RBCs is facilitated via functional interaction of ammonium (RhAG) and anion (AE1) transporters. Ammonium transport in human RBCs was inhibited in hypoxic conditions, whereas the switch of hemoglobin from R- to T-state in hypoxia restored the rate of ammonia/ammonium transport. Oxidative stress inhibits esterase activity, triggers hemoglobin oxidation to ferri-forms, Fe(III), Fe(IV), phosphatidylserine externalization, AE1 clusterization, and microparticles formation. In the conditions of oxidative stress, hypoxia prevents cell death via apoptosis by inhibiting phosphatidylserine externalization, AE1 clusterization, and microparticle formation. The obtained results indicate that hemoglobin conformation plays a significant role in the process of volume regulation not only in higher but in lower vertebrates as well. In human RBCs transport of CO2 (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\text{HCO}}_{3}^{ - }$$\end{document}) and NH3 (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\text{NH}}_{4}^{ + }$$\end{document}) is dependent on the AE1 activity, which is regulated by hemoglobin conformational changes. Hypoxic conditions prevent apoptosis of RBCs by preserving them from oxidative stress. Thus, our data clearly show that hypoxic conditions have beneficial effects on the RBC long-term storage.

中文翻译：

---

红细胞对渗透、氨和氧化应激的反应在缺氧条件下受到抑制

缺氧条件除了影响 CO2 和 O2 的运输外，还可能影响红细胞 (RBC) 的各种功能，包括离子和代谢调节、氧化应激诱导以及亚硝酸盐、氨、尿素等的运输。使用激光衍射、光谱法和流式细胞术评估低等脊椎动物和人类红细胞对低渗条件、氨和常氧和缺氧条件下氧化应激的反应。在低渗条件下，低等脊椎动物的红细胞膨胀并立即启动调节体积减少 (RVD) 反应。在我们的实验中，鲫鱼和林蛙的红细胞中的 RVD 反应被缺氧条件抑制，并通过再充氧恢复。通过铵 (RhAG) 和阴离子 (AE1) 转运蛋白的功能相互作用，促进人类红细胞中氨/铵的转运。人体红细胞中的氨转运在缺氧条件下受到抑制，而在缺氧条件下血红蛋白从 R 状态到 T 状态的转换恢复了氨/铵转运的速率。氧化应激抑制酯酶活性，触发血红蛋白氧化为亚铁形式、Fe(III)、Fe(IV)、磷脂酰丝氨酸外化、AE1 聚类和微粒形成。在氧化应激条件下，缺氧通过抑制磷脂酰丝氨酸外化、AE1 聚集和微粒形成，通过细胞凋亡防止细胞死亡。获得的结果表明，血红蛋白构象不仅在高等而且在低等脊椎动物的体积调节过程中起着重要作用。在人类红细胞中二氧化碳的运输 (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\text{HCO}}_{3}^{ - }$$\end{document}) 和 NH3 (\documentclass[12pt]{minimal } \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document }$${\text{NH}}_{4}^{ + }$$\end{document}) 依赖于 AE1 活性，而 AE1 活性受血红蛋白构象变化的调节。缺氧条件通过保护红细胞免受氧化应激来防止红细胞凋亡。因此，我们的数据清楚地表明，缺氧条件对 RBC 的长期储存有有益的影响。