Hemosiderin

Hemosiderins are a type of hemosiderin pigment. The substantive component of hemosiderins is protoheme (ferrooxychlorin), a fragile hemoprotein, a pigment of the heme series. The chelating component that brings hemosiderins into a colloidal state is xanthine monooxygenase (XMO), which oxidizes xanthine to uric acid and hydrogen peroxide. Unlike heme oxygenase, the KMO enzyme can be restored by the protoheme contained in hemosiderin. The consequence of this reduction is the transition of hemosiderin pigments into oxygenated products that have a bright yellow or orange color and give two absorption bands at 540-560 nm during electrophoresis. Other components determined by microscopy, such as hemoglobin iron, do not stain hemoglobin grains if the hemosiderin pigment has not yet settled: