Medicine Medical SuppliesDetection Kit
Histamine (which is also called beta-imidazolethylamine), in the human body is found in almost every tissue where it is stored predominately in the form of granules of tissue mast cells. Blood cells which are known as basophils are also harbouring histamine-containing granules. It is formed by the removal of a carboxyl group (decarboxylation) of the amino acid histidine, histamine is essentially classified as an organic amine molecule that is based on the structure of ammonia.
Histamine has many important roles after it has been released from the granules and these include aiding contraction of smooth muscles tissues of the stomach, lungs and uterus; the stimulation of gastric acid secretion within the stomach; acceleration of the hearth rate and increasing permeability whilst lowering blood pressure. It has also been shown to serve as a neurotransmitter where it is able to carry chemical messages between nerve cells. It is able to function through binding to histamine receptors which are located on the surface of specific cells. So far there are four kinds of binding receptors, which are called H1, H2, H3 and H4, however, its activity can also be inhibited by a number of drugs which are called antihistamines and these are able to block histamine from binding to its receptors. Conventional antihistamines have been useful in treating allergies to block H1 receptors (called H1 antagonists) examples include Tagamet (cimetidine) which has the ability to block gastric acid secretion and this has been vital in aiding to heal peptic ulcers.