PMY 302 Midterm: Histamine

• School: University at Buffalo
• Department: Pharmacology and Toxicology
• Course: PMY 302
• Professor: stewart Clark

Document Summary

Cause: food, insect stings, medicines, latex: receptors. H1: gq protein, locate in blood vessels, sm, heart, cns. H2: gs protein, locate in gastric mucosa, heart, uterus, cns: histamine effects. H1+h2: cvs, dilation of small bv (primary effect) H1: higher affinity, rapid onset and decline. H1 also increase permeability of post capillary venules: contraction of endothelial cells. Neural: h1, sensory nerve ending stimulant, mediates pain and itch (pruritus rash) red spot: intense capillary dilation. Wheal: exudation of fluid from capillaries and venules: gi effect flare: arteriolar dilation mediated by axon reflex. Histamine: h2 type: h released from ecl (enterochromaffin-like cell) parietal cell release of hcl, excessive hcl lead to gastritis, gastric ulcers, peptic acid disease, immune response effect. Systemic effects: vasodilation, permeability, sneezing, flares, nasal discharge. H level increase asthmatics, rhinitis and urticaria increase disease state: different generations of anti-h, 1st generation. Chlorpheniramine, dimenhydrinate, diphenhydramine, hydroxyzine, meclizine, promethazine (cddhmp)