08.21 - Histamine (Sweatman) - Questions Flashcards
(47 cards)
2 major sites of Histamine Biosynthesis
Mast Cells, Basophils
Enzyme that catalyzes Histamine Biosynthesis
L-Histidine Decarboxylase
3 Notable Activators of Histamine Synthesis and Release
GM-CSF, IL-3, Peptides
2 Notable inhibitors of Histmaine Synthesis and Release
Beta-antagonists; Cromolyn
3 Notable Histamine Activating Factors
Gastrin, Ca2+, Vancomycin
Ig isotype that causes Histamine
IgE
Cytokine that stimulates B cell to produce IgE
IL-4
Cytokine that stimulates TH1 to release IFN-g
IL-12
Release of histamine from granule matrix occurs by __ exchange
Cation
What percent of Mast Cell Granule does Histamine compose?
10%
Major actions of H1 receptors
SM contraction; Stim of NO formation; Endothelial cell contraction; Incr vascular permeability
Major actions of H2 receptors
Simulation of gastric acid secretion
Major actions of H3 receptors
Inhibition of NT release
Mediator of H2 signaling
AC –> cAMP –> Decr Ca2+, SIRS, PG –> Extracellular
Mediator of H1 signaling
GD –> cGMP –> PG, EDRF –> Extracellular
Histamine receptors in lung
H1 - Bronchoconstrict; H2 - Bronchodilation
Histamine receptors in heart
H1 - Slow AV conduction; H2 - Enhanced constraction
Histamine receptors in vasculature
H1, H2 - Microvasodilation; H1 - Permeability, Vasoconstriction
Histamine receptors in neural tissue
H1, H3 - Nerve ending stim, wakefullness and sedation
Histamine effects on capillaries
No effect
Histamine effects on venules
H1 - Rapid onset short term dilation (cap permeability); H2 - Slow onset persisent dilation
Histamine effects on Veins
H1 - Constriction of SM, Dilation of Endo; H2 - Dilation of SM
Histamine effects on Arteries
H1 - Constriction of SM, Dilation of Endo; H2 - Dilation of SM
Histamine effects on Arterioles
H1 - Rapid onset short term dilation; H2 - Slow onset persistent dilation
