Autacoids Flashcards
What is the importance of the lipid bilayer in regards to autacoid pdx?
excision, removal of lipid autocoids from the bilayer
Describe 3 situations which phospholipase 2 inhibition is warranted:
Rickettsial infections- insert PLA2 into membranes
Envenomations- snake/bee venom contain PLA2
Certain neoplasias- prostate, ovarian, mammary cancers cause overactive PLA2
Name 2 different uses for PG receptor agonists and one potential use for PG receptor antagonist:
Agonists- luteolysis, open angle glaucoma/ocular hypotension, gastroprotection, antithrombotic (PGI-2)
Antagonist- PGE-2 can be anthithrombotic
General basis for the opposing biological fx of PGs:
PGE1, PGE2, PGF and PGI2 receptors are all structurally similar
vasodilation vs vasoconstriction
PGE2 inhibits actin-myosin = vasodialtion
PGF2 promotes actin-myosin = vasoconstriction
platelet aggregation vs antithrombosis
PGE2 causes calcium influx = aggregation
PGI2 causes calcium satis = antithrombosis
Describe how PGF2alpha can lead to luteolysis, the 2 desired outcomes (gravid v non-gravid) of luteolysis and name 2 agonists used for this:
CL has PGF2a receptors and they cause apoptosis in luteal cells, decreases P4
gravid (implantation) - exogenous PGF2a given causes lysis of CL = abportion
non-gravid (no implantation) lysis of CL, return to estrus
Dioprost (Lutalyse) and Cloprostenol are used
Why should caution be used when giving dogs PG to treat pyometra?
make sure cervix is open or receptor activation will lead to uterine rupture and peritonitis
Be familar w/ PAF receptor antagonists, their clinical uses and one major side effect:
Rupatadine: H1-R and PAF-R antagonist
used against allergies
Lexipafant: PAF-R antagonist
used agains septic shock
Gingko bilboa plant- PAF-R antagonist
Side Effects- infertility, uterine implantation ahs inflammatory component (fusion), localized and minor but PAF is involved
Describe the two pharmacologic approaches to blocking the effects of LTs, an example of each, and what types of conditions are alleviated by these drugs
LOX inhibition- Tepoxalin
Inhibitors (antagonists) of leukotriene receptors- Montelukast (Singulair)
Human med mostly- used for rhinitis, asthma and COPD
What are the activators of clotting factors?
Activators of clotting factors
Vitamin K: needed for hepatic modification of factors II, VII, IX and X
Protamine: physically interacts with and inactivates heparin, used against severe heparin overdose
What are the inhibitors of clotting factors?
Heparin: activates antithrombin III which inactivates thrombin
Warfarin/coumarin/Coumadin: inhibits biochemical recycling of Vit K
NSAIDs: inhibit synthesis of PGs, PGE2R on platelets promote aggregation
What is berapost?
Prostacyclin (PGI2) receptor agonists
used against peripheral occlusive arterial disease
what is used to stimulate megakayocyte release from the bone marrow?
Vincristine (and vinblastine): anti-cancer drugs that inhibit pseudopods that allow for megakaryocyte attachment to bone marrow matrix. Used against thrombocytopenia- bad news is that it has to be given IV
What are the two pharamcologic approaches to blocking the effects of leukotrienes? What are examples and what are conditions that are alleviated by them?
LOX inhibition: Tepoxalin
Inhibit LT receptors: Montelukast; rhinitis, asthma, and COPD
