allergic and inflammatory responses are triggered by the release of chemicals such as histamine and serotonin from mast cells While the sources also note that basophils (a type of white blood cell) secrete heparin, histamine, and serotonin to involve themselves in inflammatory reactions histamine is the characteristic secretion of mast cells in the context of tissue injury and allergy. Other options are incorrect because prothrombin is an inactive plasma protein involved in the blood-clotting cascade and antibodies are produced by B-lymphocytes