Histamine causes
ref Robbins 7/e p64;9/e p73 As pa of an immune response to foreign pathogens, histamine is produced by basophils and by mast cells found in nearby connective tissues. Histamine increases the permeability of the capillaries to white blood cells and some proteins, to allow them to engage pathogens in the infected tissues.
Hypeension
Vasoconstriction
Vasodilation
Tachycardia
General anatomy