Shimizu S, Sakata S, Enoki Y, Ohga Y, Oki I, Kohzuki H
Second Department of Physiology, Nara Medical University, Japan.
Jpn J Physiol. 1989;39(6):833-46. doi: 10.2170/jjphysiol.39.833.
Temporal changes of plasma erythropoietin (Epo) in mice exposed to hypobaric hypoxia were studied by a fetal mouse liver cell culture method. Since a colony formation inhibitory activity was found in the mouse plasma, thirteen pretreatment procedures for bioassay were compared and the procedure of shaking with chloroform followed by dialysis was concluded to be the best. When normal mice (P50 = 40.4 +/- 2.2 Torr) were exposed to hypoxia of 350 Torr, the plasma Epo level was elevated, with peak at the 2nd to 3rd day, and afterwards declined gradually. On the contrary, cyanated mice (P50 = 30.1 +/- 1.5 Torr) showed much less of the Epo response when exposed to 350 Torr. Under 200 Torr hypoxia, both mice exhibited a similar and remarkable extent of the response. These results suggest that the renal Epo-producing tissue or its oxygen-sensing system is less hypoxic in cyanated mice than in normal mice under 350 Torr, and that the physiologically optimal oxygen affinity of blood is variable depending on hypoxic degrees. The fact that the inhibitory activity showed an inverse temporal change to that of Epo, suggested a possible important role of this activity in the regulation of erythropoiesis under hypoxia.
采用胎鼠肝细胞培养法研究了低压低氧暴露小鼠血浆促红细胞生成素（Epo）的时间变化。由于在小鼠血浆中发现了集落形成抑制活性，比较了生物测定的13种预处理程序，得出氯仿振荡后透析的程序最佳。正常小鼠（P50 = 40.4 +/- 2.2 Torr）暴露于350 Torr的低氧环境时，血浆Epo水平升高，在第2至3天达到峰值，随后逐渐下降。相反，氰化小鼠（P50 = 30.1 +/- 1.5 Torr）在暴露于350 Torr时Epo反应要小得多。在200 Torr低氧条件下，两种小鼠表现出相似且显著的反应程度。这些结果表明，在350 Torr条件下，氰化小鼠的肾脏Epo产生组织或其氧传感系统比正常小鼠的缺氧程度低，并且血液的生理最佳氧亲和力随缺氧程度而变化。抑制活性与Epo呈相反的时间变化这一事实，表明该活性在低氧条件下红细胞生成的调节中可能起重要作用。
