Granules of these cells dye with basic stains into blue color. Granules contain heparin, histamine, serotonin, peroxidase, acid phosphatase, histidinecarboxylase (the enzyme of histamine synthesis). Phagocyte activity is low.
Functions of basophiles
Participate in allergic reactions. Antigen-antibody complex affects degranulation of basophiles and histamine release. In low concentrations histamine interacts with H1-receptors and causes basic manifestations of allergic reactions: dilatation of blood vessels, increase of vessel wall permeability, irritation of nervous endings, which cause itching, pains, and increase of formation and secretion of mucus in respiratory pathways, contraction of smooth muscles in bronchi. In big concentrations histamine interacts with H2-receptors and causes extinction of these reactions due to inhibition of basophiles degranulation.
Participate the development of inflammation, especially during last (regenerative) phase: heparin predicts blood coagulation in inflammation source; histamine dilates capillaries that help resolution and healing.
Regulation of vessel wall permeability (increased by histamine and serotonin).
Participates hemostasis (heparin is an anticoagulant, histamine causes vessel spasm after damage).
The increase of basophiles amount (basophilia) is rare. It can cause the development of chronic myeloleucosis, hemophilia, and polycythemia.