Schade S G, Fried W
Proc Soc Exp Biol Med. 1976 Jan;151(1):78-83. doi: 10.3181/00379727-151-39147.
We report experiments to determine the availability for new hemoglobin production of radioiron from nonviable red cells at various times after deposition in the reticulo-endothelial system and to determine the relative availability of radioiron derived from hemolysates versus that derived from nonviable red cells. When heated nonviable red cells labeled with 59Fe are injected into polycythemic mice the iron is deposited in the reticulo-endothelial system, and less than 1% of it is reutilized for hemoglobin synthesis. If the polycythemic mice are given nonviable red cells 48 hours after exposure to hypoxia, when hemoglobin synthesis is maximal, 25% of the iron is reutilized. When the cells are given 36 hr after exposure to hypoxia, iron reutilization declines to 16%, and when exposure to hypoxia is further delayed, reutilization of the iron falls to a plateau level of 11%. Radioiron from hemolysates, primarily deposited in parenchymal cells of the liver, is less available for new hemoglobin synthesis than is radioiron from nonviable red cells, which is primarily deposited in Kupffer cells of the liver. When transferrin-bound iron is given to polycythemic mice, this iron is also deposited in parenchymal cells of the liver and is also less available for new hemoglobin synthesis. Thus, in relation to an erythropoietic stimulus, the site and time of deposition of iron influence its accessibility for erythropoiesis.
我们报告了一些实验，以确定在网状内皮系统中沉积后不同时间，来自无活力红细胞的放射性铁用于新血红蛋白生成的可用性，并确定来自溶血产物的放射性铁与来自无活力红细胞的放射性铁的相对可用性。当将用59Fe标记的加热过的无活力红细胞注射到红细胞增多症小鼠体内时，铁沉积在网状内皮系统中，其中不到1%被重新用于血红蛋白合成。如果在暴露于缺氧状态48小时后给红细胞增多症小鼠注射无活力红细胞，此时血红蛋白合成达到最大值，则25%的铁会被重新利用。当在暴露于缺氧状态36小时后给予细胞时，铁的再利用率降至16%，而当进一步延迟暴露于缺氧状态时，铁的再利用率降至11%的稳定水平。来自溶血产物的放射性铁主要沉积在肝脏实质细胞中，与主要沉积在肝脏枯否细胞中的来自无活力红细胞的放射性铁相比，其用于新血红蛋白合成的可用性较低。当给红细胞增多症小鼠注射与转铁蛋白结合的铁时，这种铁也沉积在肝脏实质细胞中，并且其用于新血红蛋白合成的可用性也较低。因此，相对于促红细胞生成刺激，铁的沉积部位和时间会影响其对红细胞生成的可及性。
