Histamine

Histamine is located in mast cells, endocrine cells of the gut, blood cells and in some cells of the peripheral and central nervous system. Histamine is a potent vasodilator when secreted by mast cells found in various tissues as a result of allergic hypersensitivity or inflammation. In the central nervous system, Histamine is putative neurotransmitter. In the brain, its highest content has been found in the hypothalamus and in certain areas of the mesencephalon. The Histamine antiserum has a sensitivity level capable of detecting the low level Histamine contents of the brain.