Rogers R A, Tasat D R, Warner A E, Brain J D
Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts 02115.
J Leukoc Biol. 1994 Dec;56(6):692-701. doi: 10.1002/jlb.56.6.692.
Pulmonary intravascular macrophages (PIMs) adhere to the endothelium of lung capillaries and sequester circulating particles and pathogens from the blood. Iron oxide (gamma Fe2O3) 5 mg/kg, administered intravenously, specifically labeled PIMs in situ within the living sheep. Attempts to isolate gamma Fe2O3-labeled PIMs using vascular perfusion (VP) procedures yielded few cells. To improve recovery of PIMs, a proteolytic lung digestion (PLD) procedure was developed. Following PLD, gamma Fe2O3-containing PIMs were recovered by magnets and the amount of gamma Fe2O3 present measured by fluxgate magnetometry. Proteolytic lung digestion recovered 34% of the total gamma Fe2O3 in lung samples and yielded 2 x 10(5) PIMs/g lung with 95% viability. In contrast, VP recovered only 3% of the total gamma Fe2O3 in the lung; furthermore, less than 2% of the recovered gamma Fe2O3 was cell associated. Proteolytic lung digestion followed by magnetic separation is an effective way to recover viable sheep PIMs for in vitro study.
肺血管内巨噬细胞（PIMs）附着于肺毛细血管内皮，从血液中隔离循环颗粒和病原体。静脉注射5mg/kg的氧化铁（γ-Fe2O3）可在活体绵羊体内原位特异性标记PIMs。尝试使用血管灌注（VP）程序分离γ-Fe2O3标记的PIMs，得到的细胞很少。为了提高PIMs的回收率，开发了一种蛋白水解肺消化（PLD）程序。PLD后，通过磁铁回收含γ-Fe2O3的PIMs，并通过磁通门磁力计测量γ-Fe2O3的含量。蛋白水解肺消化回收了肺样本中34%的总γ-Fe2O3，每克肺产生2×10⁵个PIMs，存活率为95%。相比之下，VP仅回收了肺中3%的总γ-Fe2O3；此外，回收的γ-Fe2O3中不到2%与细胞相关。蛋白水解肺消化后进行磁分离是回收活绵羊PIMs用于体外研究的有效方法。
