Splenic contraction-induced reversible increase in hemoglobin concentration in intermittent hypoxia
Splenic contraction-induced reversible increase in hemoglobin concentration in intermittent hypoxia
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DOI：
10.1152/jappl.1999.86.1.181
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发表时间：
1999-01-01
影响因子：
3.3
通讯作者：
Gonzalez, NC
中科院分区：
文献类型：
--
作者：
Kuwahira, I;Kamiya, U;Gonzalez, NC
本文研究了间歇性低氧（IHx）对大鼠血液血红蛋白浓度（[Hb]）的影响及其机制。每日低氧暴露时间较长的IHx方案显示持续性红细胞增多症;然而，尚不清楚在无红细胞增多症的方案中，[Hb]在低氧期间是否短暂增加。缺氧产生可逆的[Hb]增加后4天的IHx，但不是在常氧对照组（NxC）或较短的IHx后。脾切除术消除了这种现象。缺氧期间IHx和NxC组的血浆肾上腺素和去甲肾上腺素水平相当，但IHx组肾上腺素诱导的[Hb]增加更大。α（1）和α（2）肾上腺素能受体阻断剂（酚妥拉明）和α（2）肾上腺素能受体阻断剂（育亨宾）可消除IHx大鼠[Hb]的升高。相反，α（2）-受体刺激（羟甲唑啉）增加[Hb]在常氧IHx，但不是在NxC。总之，该IHx方案通过增加α（2）-肾上腺素受体反应介导的脾收缩导致缺氧期间可逆的[Hb]增加。这可能会保护缺氧时的O-2供应，而不会在常氧时造成红细胞增多症的心血管负担。
The effect of intermittent hypoxia (IHx) on blood hemoglobin concentration ([Hb]) and the underlying mechanisms were studied in rats exposed to 10% O-2, 1 h/day, for up to 5 wk. IHx protocols with longer daily hypoxic exposure show persistent polycythemia; however, it is unknown whether [Hb] increases transiently during hypoxia in protocols without polycythemia. Hypoxia produced a reversible [Hb] increase after 4 days of IHx but not in normoxic controls (NxC) or after shorter period of IHx. Splenectomy abolished the phenomenon. Plasma epinephrine and norepinephrine levels during hypoxia were comparable in IHx and NxC groups, but the epinephrine-induced [Hb] increase was larger in IHx. The alpha(1)- and alpha(2)-adrenoreceptor blockade (phentolamine) and alpha(2)-blockade (yohimbine) abolished the [Hb] increase of IHx rats. Conversely, alpha(2)-receptor stimulation (oxymetazoline) increased [Hb] during normoxia in IHx but not in NxC. In conclusion, this IHx protocol results in reversible [Hb] increases during hypoxia via splenic contraction mediated by increased alpha(2)-adrenoreceptor response. This may protect O-2 supply during hypoxia without the cardiovascular burden of polycythemia during normoxia.