Clark Cheryl A, Burns Jennifer M, Schreer Jason F, Hammill Mike O
Department of Biological Sciences, University of Alaska Anchorage, 3211 Providence Drive, Anchorage, AK 99508, USA.
Gen Comp Endocrinol. 2006 Jul;147(3):262-7. doi: 10.1016/j.ygcen.2006.01.009. Epub 2006 Feb 28.
Tissue hypoxia elicits the production of erythropoietin (Epo), a hormone that stimulates red blood cell production. In young diving mammals, oxygen is stored primarily in the blood, and blood oxygen stores increase significantly during the first weeks of life. In an effort to establish the role of Epo during this period of blood development, this study measured Epo concentration in plasma of 134 harbor seal (Phoca vitulina) pups and adults. Concurrent measurements of hematocrit (Hct), hemoglobin concentration [Hb], and red blood cell (RBC) counts allowed the evaluation of the effect of Epo on blood oxygen store capacity. Erythropoietin and most blood parameters varied with age. At birth, neonatal [Hb], Hct, and RBC were elevated, possibly due to the rapid expansion of plasma volume associated with growth rates of 0.5 kg/day. In contrast, Epo concentration increased from 6.64 +/- 0.83 mU/ml in newborns to 9.53 +/- 0.86 mU/ml in early nursing pups. Erythropoietin concentration remained elevated above newborn and adult concentration (5.71 +/- 0.79 mU/ml) through weaning, suggesting that Epo was responding to tissue hypoxia brought on by early anemia. Since similar changes in erythropoietin have been documented in terrestrial mammals, it appears that Epo plays a similar role in the blood development of harbor seals.
组织缺氧会引发促红细胞生成素（Epo）的产生，这是一种刺激红细胞生成的激素。在幼年潜水哺乳动物中，氧气主要储存在血液中，并且在出生后的头几周内血氧储备会显著增加。为了确定Epo在这一血液发育阶段的作用，本研究测量了134只港海豹（Phoca vitulina）幼崽和成体血浆中的Epo浓度。同时测量血细胞比容（Hct）、血红蛋白浓度[Hb]和红细胞（RBC）计数，以便评估Epo对血氧储备能力的影响。促红细胞生成素和大多数血液参数随年龄而变化。出生时，新生幼崽的[Hb]、Hct和RBC升高，这可能是由于血浆量随着每天0.5千克的生长速度快速增加所致。相比之下，Epo浓度从新生儿的6.64±0.83 mU/ml增加到早期哺乳幼崽的9.53±0.86 mU/ml。促红细胞生成素浓度在断奶前一直高于新生儿和成体浓度（5.71±0.79 mU/ml），这表明Epo是对早期贫血引起的组织缺氧做出反应。由于在陆生哺乳动物中也记录到了促红细胞生成素的类似变化，因此Epo在港海豹的血液发育中似乎发挥着类似的作用。
