Histamine is an autocoid which means a self healing substance. It is found in plenty in the region of wounds and infection indicating its role in healing. Even the itch during wound healing also indicates histamine presence.
Histamine is present in many body cells and tissues. It is an essential chemical which control body physiology.
It acts by two receptors viz. H1, H2 while H3 is not prominent in health care.
Functions of histamine:
In Whole body: Histamine is present in mast cells, so during an infection or wound, it is accumulated there. This histamine acts to attract leukocytes (white blood cells). It produces constriction in lings, intestine and lower blood pressure.
In other tissue like brain, skin, stomach it is also present without mast cells.
In Stomach: Histamine stimulates acid secretion in stomach. It can be modulated to relive acidity and in treatment of peptic ulcers.
In inflammation: Histamine play a important role in inflammation. During a bruise or blow, it shows accumulation in the region of blow. IT causes redness, circular swelling in the region. It also produces itch in the region. But besides histamine there are other chemical which also modulate inflammation.
In the brain: Histamine has affects on wakefulness and thirst.
It also triggers release of Adrenalin hormone from adrenal gland.
Drugs which work to mitigate histamine include
Anti-histamine drugs like citrizine, promethiazine, dimenhydrinate etc. These drugs are used in times of common cold, allergy, vomiting during pregnancy, motion sickness etc.
Besides we use anti-histamine which work in the stomach region to counter the formation of acid. These are used as antacids and they include ranitidine, famotidine etc.
But these drugs should be used only on doctors prescription as they could produce untoward actions.