B. Inflammatory Mediators 1. CO2 Tryptophan monooxygenase 5-OHTryptophan decarboxylase 3. Prostaglandins are also made from arachidonic acid and result in vasodilation, contraction of pulmonary smooth-muscles, and platelet aggregation. Cyclooxygenase pathway 5. Bradykinin causes increased vascular permeability and smooth-muscle contraction.
Proteases cause destruction of blood-vessel basement membrane, and bronchial mucous secretion.
These receptor molecules allow the mast cell and basophil to passively acquire any IgE molecule, regardless of the IgE molecule's antigen-binding site specificity. If the allergen binds to two IgE molecules which are next to one another in the mast cell's or basophil's membrane, these IgE molecules will be cross-linked. The cross-linkage of these IgE molecules results in transmission of intracellular signals, which ultimately leads to degranulation, and the release of histamine, serotonin, etc., during the primary phase of the response. After the primary phase, as the cell degranulates, there will be dissipation of the cell's membrane - and in the meantime there will have been synthesis and secretion of bradykinin, and prostaglandins and leukotrienes as the result of arachidonic acid catabolism. The treatment for such conditions, depends upon whether or not the reactions are localized, regional or systemic.