Title (PCHS) PHARCHEM 3 - ANTIHISTAMINES AND RELATED ANTIALLERGIC AGENTS (WITH PERMISSION).pdf ✅

ANTIHISTAMINES AND RELATED ANTIALLERGIC AGENTS
❖ Histamine is an endogenous autacoid, a term that means “self remedy.” Introduction.
❖ Once produced, histamine is stored in mast cells and basophils. Release is primarily the result of the interaction of an antigenic stimulus with IgE antibodies on the cell surface. Introduction.
❖ The result of the antigen– antibody reaction is stimulation of phospholipase C, which increases intracellular levels of inositol triphosphate and calcium, and elevates levels of diacylglycerol in the membrane. The increased concentration of these second messengers leads to exocytosis. In mast cells, this process is also known as degranulation. Introduction.