Autacoids Flashcards
what do autacoids do?
act like local hormones: brief duration, act near site of synthesis
what are two common things included in autacoids?
histamine
antihistamines
which species have high histamine in tissues?
goat and rabbit
what are the two general stores of histamine?
mast cell pool (mast cells and basophils)
non-mast cell pool
what does histamine release mediate?
vasodilation
itching
smooth muscle contraction
edema
how do guinea pigs respond to histamine release?
bronchial constriction and death (like dogs and humans)
what does histamine and anaphylaxis produce in carnivores?
hypotension and hepatomegaly
what does histamine do in the GI tract?
potent stimulant of hydrochloric acid secretion by gastric mucosa
what does the H1 receptor do?
anaphylaxis
inflammation
allergies
adverse drug reactions
pruritus
what does the H2 receptor do?
regulates gastric secretion
some inflammation
what does the H3 receptor do?
neurotransmitter release from neurons
H1 antagonists are ________________________
inverse agonists/antagonists/?
what do H1 antagonists do?
counter the effects of histamine on bronchial, intestinal, uterine, and vascular smooth muscle
suppress itching
allergic reactions and anaphylaxis
what do H2 antagonists do?
block gastric stimulating effects of histamine
what does heparin do?
anti hemostasis agent
antithrombotic and anticoagulation effects
potentiates action of antithrombin (AT)
what characterizes an arterial thrombosis?
disorders of high shear force and arterial injury
induce platelets to become activated
hypercoagulable state
clot is platelet rich
platelets embedded in fibrin
antiplatelet
what drugs potentially release histamine as an adverse effect?
curare
morphine
codeine
papaverine
meperidine
polypeptide antibiotics
atropine
what histamine receptor plays a part in immunomodulation?
H4
how does H4 immunomodulate?
immune cell chemotaxis
immune response
inflammation
_________ is the predominant enzyme found in platelets
COX-1
what are some antiplatelet drugs?
aspirin
clopidogrel
in which disease processes are fibrinolytic agents considered?
feline arterial thromboembolism
canine pulmonary thromboembolism
what are some things included in autacoids?
eicosanoids
angiotensin
neurotensin
NO
kinins
histamine
serotonin
endothelin
palmioylethanolamide
histamine is high in ________________, low in ____________________
goat and rabbit
horse, dog, cat, and human
what is the non-mast cell pool of histamine?
gastrointestinal tract
CNS
dermis
other organs
what histamines are in the mast cell pool?
those that participate in inflammatory responses, allergic phenomena, shock, adverse drug reactions, and other forms of cellular insult/tissue damage
what type of response does release of histamine result in in rabbits?
pulmonary arterioles constrict
right heart dilates
what type of physical injuries elicit a histamine release?
skin lesions
urtication
dermal reaction due to cold or heat
what does histamine in the non-mast cell pool elicit from sensory nerve endings?
itching and pain
what is the intracellular signal cascade of H1 receptors?
Ca increase
phospholipase C
NFkB
what differentiates second generation H1 antagonists?
lack antimuscarinic properties and do not cross blood-brain barrier
what are the side effects of antihistamines- H1 antagonists?
relatively nontoxic
sedation or CNS excitement, GI disturbances, parasympatholytic action, local anesthetic properties, allergenic properties, teratogenic effects
what are H2 antagonists used for?
to prevent and treat gastric ulceration
how is heparin reversed?
protamine sulfate
what is heparin used to treat?
hypercoagulability disorders/coagulation disorders
thromboembolism, venous thrombosis, disseminated intravascular coagulopathy, pulmonary thromboembolism
what is important about warfarin and coumarin derivatives?
inactive in vitro: need liver
what do warfarin and coumarin derivatives do?
inhibit blood coagulation mechanisms: hepatic synthesis of vitamin K dependent clotting factors
__________ is an antiplatelet prodrug
clopidogrel
