Mononuclear phagocyte system macrophages

Figure 8.1 Body iron stores and daily iron exchange. The figure shows a schematic representation of the routes of iron movement in normal adult male subjects. The plasma iron pool is about 4 mg (transferrin-bound iron and non-transferrin-bound iron), although the daily turnover is over 30 mg. The iron in parenchymal tissues is largely haem (in muscle) and ferritin/haemosiderin (in hepatic parenchymal cells). Dotted arrows represent iron loss through loss of epithelial cells in the gut or through blood loss. Numbers are in mg/day. Transferrin-Tf haemosiderin - hs MPS - mononuclear phagocytic system, including macrophages in spleen and Kupffer cells in liver.

D. A. Hume, P. Pavli, R. E. Donahue, and I. J. Fidler, The effect of human recombinant macrophage colony-stimulating factor (CSF-1) on the murine mononuclear phagocyte system in vivo, J.Immunol. 141, 3405-3409 (1988). 

About 70% of the total body store of iron (-5 g) is contained within erythrocytes. When these are degraded by macrophages of the reticuloendothelial (mononuclear phagocyte) system, iron is liberated from hemoglobin. Fe can be stored as ferritin (= protein apoferri-tin + Fe ) or returned to erythropoiesis sites via transferrin. 

Also termed the mononuclear phagocytic system, monocytes circulate in the blood and macrophages in the tissues. In the bone marrow during hematopoiesis, the... 

The Mononuclear Phagocyte System as a Source of Wound-Site Monocytes and Macrophages... 

In addition to the issue of endothelial permeability, the effect of macrophages in direct contact with the blood circulation (e.g. Kupffer cells in the liver) on the disposition of carrier systems must be considered. Unless precautions are taken, particulate carrier systems are readily phagocytosed by these macrophages and tend to accumulate in these cells. Phagocytic uptake by the cells of the mononuclear phagocyte systems (MPS also sometimes known as the reticuloendothelial system, RES) has been described in Chapter 1 (Section 1.3.3.2). The MPS comprises both ... 

When a foreign substance comes in contact with the human body, the system initiates its host defense m hanisms involving what may be called the inflammatory response. For instance, the presence of foreign materials causes acute inflammatory changes, evokes an immune reaction, or is associated with infiltrate of cells predominantly of the mononuclear phagocyte after an acute inflammatory reaction. It is the macrophage that is the most important cell in the mononuclear phagocyte system (MPS) which plays a major role in all these kinds of inflammation. 

Macrophages are produced hy rapidly dividing precursor cells in the hone marrow and the daughter cells are released into the hlood-stream. This mononuclear phagocytic system consists of several types of cells widely distributed throughout the hody. 

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