MICROANATOMY

Detailed explanation-1: -Mast cells and basophils represent the most relevant source of histamine in the immune system. Histamine is stored in cytoplasmic granules along with other amines (e.g., serotonin), proteases, proteoglycans, cytokines/chemokines, and angiogenic factors and rapidly released upon triggering with a variety of stimuli.

Detailed explanation-2: -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-3: -Basophils have been shown to produce effector molecules such as histamines and leukotrienes in response to IgE-mediated activation16.