MICROANATOMY

Detailed explanation-1: -During allergic reactions, basophils release two enzymes, histamine and heparin. Histamine enlarges your blood vessels to improve blood flow and heal the affected area. Histamine opens pathways for other cells in your immune system to quickly target and respond to the allergen.

Detailed explanation-2: -Mast cells and basophils represent the most relevant source of histamine in the immune system.

Detailed explanation-3: -Basophils migrate to injury sites and cross the capillary endothelium to accumulate in the damaged tissue, where they discharge granules that contain histamine (dilates blood vessels) and heparin (prevents clotting).

Detailed explanation-4: -Basophils are also granulocytes, or white blood cells that have granules, or small particles, attached to them. These small particles are filled with enzymes, like histamine, that are released during allergic reactions. Basophils are the only white blood cells circulating around your body that contain histamine.

Detailed explanation-5: -In this report, we show that eosinophils express histamine H4, but not H3 receptors. Since mast cells are the major producers of histamine and both mast cells and eosinophils are known effector cells in allergic reactions, the possible role of mast cells in the recruitment of eosinophils via histamine was investigated.