Histamine, Serotonin, and the Ergot Alkaloids Flashcards
hormone or chemical produced by the body that acts locally to exert a biological effect
autoacoid
important mediator of immediate allergic and inflammatory reactions
histamine
modest role in anaphylaxis
histamine
formed by decarboxylation
histamine
either stored in granules or rapidly inactivated by 2 enzymes
- monoamine oxidase
- diamine oxidase
histamine
stored in mast cells (tissues), basophils (blood), enterochromaffin cells of the gut, and some neurons
histamine
which is an autoacoid?
histamine
precursor of histamine
histidine
2 enzymes that breaks histamine down?
monoamine oxidase and diamine oxidase
amine is in them- from histAMINE
histamine release is by :
Immune
Chemical
Mechanical
Most important pathohysiological mechanism of histamine release from __ and __ cells
mast cells and basophils
Sensitization of mast cells and basophils with __ causes rapid DEGRANULATION
IgE
degranulation of mast cells and basophils are dependent on what ___
Calcium and Energy Dependent
the immune release of histamine can exert a negative feedback through __ receptors
H2
what chemicals can cause histamine release?
morphine and tubocurarine
t/f chemical release of histamine is not dependent on energy or mast cell granulation
true
mast cell injury can cause degranulation and release is an example of what type of histamine release?
mechanical
cell wall is being destroyed so the cell’s goodies are being released
how many receptor subtypes of histamine are there? how many do we care about?
4, 2
Histamine subtypes receptor that mediates allergic rhinitis
H1
Histamine subtype receptor that mediates stomach acid production
H2
Gq coupled receptor that increases IP3 and DAG formation, histamine
H1
Gs coupled receptor that increased cAMP and PKA activity, histamine
H2
Gi coupled receptor, decrease in cAMP
H3 and H4
Histamine subtype that is in the SM, endothelium and brain
H1
Histamine subtype that is in the Gastric mucosa, cardiac muscle, mast cells and brain
H2
stimulation of sensory nerve endings, causes pain and itching via ___ stimulation - nervous system effects
H1
histamine will cause tachycardia with decrease of blood pressure, this is caused by __
vasodilation via H1 receptors
vasodilation of H1 receptors is caused by __ production of NO in the endothelium
increased
what causes separation of endothelial cells in the microcirculation? permits fluids and small proteins to escape to the perivascular space, this is responsible for hives and the hallmark of histamine release in the skin
edema
t/f asthmatics are more sensitive to histamine than nonasthmatics.
true - this is how you can test for asthma!
histamine has what kind of effect on the GI SM?
contraction - LARGE doses may cause DIARRHEAAAAAA
t/f histamine may induce contractions during anaphylaxis and cause abortion
t, so sad
histamine stimulates gastric acid secretion via __ receptors
H2
what is characteristics red spot, edema, and flare responses to intradermal histamine administration?
triple response
CNS effect of histamine?
nociception
smooth muscle actions opposite to histamine, used to counteract the effects of histamine during anaphylaxis
epinephrine
also known as mast cell stabilizers
release inhibitiors of histamine antagonism
prevent the degranulation of mast cells
release inhibitiors of histamine antagonism
used in the treatment of asthma
release inhibitiors of histamine antagonism
cromolyn and nedocromil are in what section?
release inhibitiors of histamine antagonism
antagonists for __ and __ are readily available (OTC) and are of the great therapeutic benefit
H1 and H2
Antagonists of __ and __ are not available for clinical use and are POINTLESSSSS
H3 and H4
What do you have to take for days before you see a response, dont work acutely?
Cromolyn and Nedodromil
what group of histamine antagonists are in generations?
H1 and First & Second generation
__ generation is generally less selective for H1 Receptors and is associated with the majority of the side effects
first generation