上降充通大粤 SHANGHAI JIAO TONG UNIVERSITY 1896 1920 1987 2006 Effects of Histamine 2.Nervous system: powerful stimulant of sensory nerve endings,especially those mediating pain and itching. 3.Smooth muscle: contraction (H1-R)-bronchoconstriction,abort 4.Secretory tissues: stimulant of gastric acid secretion(H2-R) 5.The“triple response”: Intradermal injection of histamine causes a characteristic wheal-and-flare response.Effects of Histamine 2. Nervous system: powerful stimulant of sensory nerve endings, especially those mediating pain and itching. 3. Smooth muscle: contraction (H1-R) → bronchoconstriction, abort. 4. Secretory tissues: stimulant of gastric acid secretion (H2 -R) 5. The “triple response”: Intradermal injection of histamine causes a characteristic wheal-and-flare response