Basophils

• Basophils are rare, accounting for less than 1 percent of the circulating WBC population
• Basophils release granules into interstitial fluids of injury sites
• Basophils granules contain histamine and heparin
• Histamine dilates blood vessels and heparin prevents blood clotting
• Stimulated basophils also release other chemicals that attract eosinophils and other basophils to the area