histamine molecule. it is amine, nitrogenous compound, stimulant of gastric secretion, vasodilator, and centrally acting

allergen allergic amine atom atomic biogeni blue carbon chemical chemistry compound dark education formula histamin histamine hydrogen hypersensitivity illustration immune itch mediator metabolism model molecular molecule muscle nervous neuro neurotransmitter nflammation nitrogen nitrogenous organic physiology science stimulant structure study system transmitter vasodilator vector white