Malgor L A, Blanc C C, Klainer E, Irizar S E, Torales P R, Barrios L
Blood. 1975 May;45(5):671-9.
A stimulatory effect on bone marrow cellularity was observed in normal and nephrectomized rats continuously infused with T3 and T4. Results of bone marrow studies are expressed in absolute numbers of total nucleated erythroid cells per milligram of femoral marrow at the beginning and after 8 hr of continuous intravenous infusions. Administration of T3 and T4 to nephrectomized rats produced a marked and significant increase in total erythroid cells counted. After differential analyses of the nucleated erythroid elements, a significant increase in all erythroid cell types was also observed. Similar results were seen in a control group of rats in which both ureters have been previously ligated and in groups of nephrectomized rats receiving rabbit antiserum against erythropoietin before starting the intravenous infusions of T3 and T4. These results indicate that stimulation of marrow erythropoiesis produced by thyroid hormones in our system is not dependent on renal or extra-renal production of erythropoietin. The progressive introduction of T3 and T4 into the circulation of rats with bilateral nephrectomy or ureter-ligated normal rats, may overload the mechanism of transport of these hormones in plasma. As a consequence, a progressive increase in free active forms of T3 and T4 in plasma may occur. Our interpretation of the present findings is that thyroid hormones stimulate directly bone marrow erythropoiesis. This stimulation is clearly evident when high levels of free active forms of thyroid hormones are present in plasma.
在持续输注T3和T4的正常大鼠和肾切除大鼠中，观察到对骨髓细胞数量有刺激作用。骨髓研究结果以连续静脉输注开始时和8小时后每毫克股骨骨髓中总核红细胞的绝对数量表示。给肾切除大鼠施用T3和T4后，计数的总红细胞明显且显著增加。对有核红细胞成分进行鉴别分析后，还观察到所有红细胞类型均显著增加。在先前双侧输尿管结扎的大鼠对照组以及在开始静脉输注T3和T4之前接受抗促红细胞生成素兔抗血清的肾切除大鼠组中也观察到类似结果。这些结果表明，我们的系统中甲状腺激素对骨髓红细胞生成的刺激不依赖于促红细胞生成素的肾脏或肾外产生。将T3和T4逐步引入双侧肾切除大鼠或输尿管结扎正常大鼠的循环中，可能会使这些激素在血浆中的运输机制超负荷。因此，血浆中T3和T4的游离活性形式可能会逐渐增加。我们对目前研究结果的解释是，甲状腺激素直接刺激骨髓红细胞生成。当血浆中存在高水平的甲状腺激素游离活性形式时，这种刺激作用明显。
