Autocoids at University Of Bradford | Flashcards & Summaries

Select your language

Suggested languages for you:
Log In Start studying!

Lernmaterialien für Autocoids an der University of Bradford

Greife auf kostenlose Karteikarten, Zusammenfassungen, Übungsaufgaben und Altklausuren für deinen Autocoids Kurs an der University of Bradford zu.

TESTE DEIN WISSEN
What are eicosanoids?
Lösung anzeigen
TESTE DEIN WISSEN
•Lipid autocoids derived from membrane phospholipids
–Prostanoids
–Leukotrienes
•Eicosanoids, unlike histamine, are not stored preformed in the tissues; they are generated as required from membrane phospholipids
Lösung ausblenden
TESTE DEIN WISSEN
What are cyclooxygenase enzymes?
Lösung anzeigen
TESTE DEIN WISSEN
-Two forms of cyclooxygenase exist in the body
-COX-1 occur in most cells as a constitutive enzyme
-COX-2 is induced mainly in inflammatory cells by an inflammatory stimulus
•COX-2 selective inhibitors (Coxibs) are now available such as Celecoxib, etoricoxib,  which cause less GI side effects
Lösung ausblenden
TESTE DEIN WISSEN
What are the actions of histamine and the related receptors?
Lösung anzeigen
TESTE DEIN WISSEN
•Vasodilatation - H1 receptors
•Increases capillary permeability - H1 receptors
Contraction of ileal smooth muscles  - H1 receptors
•Contraction of bronchial smooth muscles - H1 receptors
•Itch and pain due to stimulation of nerve endings - H1 receptors
•Gastric acid secretion  - H2 receptors
•Increases heart rate & output -H2 receptors
Lösung ausblenden
TESTE DEIN WISSEN
What are type 1 hypersensitivity reactions?
Lösung anzeigen
TESTE DEIN WISSEN
•Histamine is the first mediator to be released in allergic reactions
-responsible for many signs of inflammation. 
• acting on H1 receptors
Lösung ausblenden
TESTE DEIN WISSEN
How is gastric acid secreted and how can consequential conditions be treated?
Lösung anzeigen
TESTE DEIN WISSEN
•Histamine provide one of the stimulus to gastric parietal cells to secrete HCl. 
•Conditions, such as Gastro-oesophageal Reflux Disease (GORD), peptic and duodenal ulcers
-conditions are caused by excessive gastric acid secretion 
-can be treated with  H2 receptor antagonists
Lösung ausblenden
TESTE DEIN WISSEN
What histamine antagonists are available and their features ?
Lösung anzeigen
TESTE DEIN WISSEN
•H1-receptor antagonists known as antihistamines
•Older antihistamines (1st generation) cause sleepiness and less safe unlike 2nd generation antihistamines which interact with other medications better hence its safer to use
Non-sedating antihistamines: Terfenadine
–Used to treat hay fever (seasonal rhinoconjunctivitis) and urticaria.
•Reduce rhinorrohea, sneezing and pruritus.
•Other uses: sedative, anti-emetic, antitussive
–administered orally but can be given by injection or topically
H2-receptor antagonists such as Cimetidine
–Used to decrease gastric acid secretion which 
•Helps heal peptic and duodenal ulcers
•Gastro-oesophageal reflux disease
–Less effective than Proton Pump Inhibitors (e.g. omeprazole) but have prominent effects on basal acid secretion and suppress nocturnal acid secretion.
Lösung ausblenden
TESTE DEIN WISSEN
What is the triple response to histamine?
Lösung anzeigen
TESTE DEIN WISSEN
-triple response is caused by intradermal injection of histamine
- red spot extending few mms, appears within a few seconds and reach maximum in about a minute
- red spot caused from the direct vasodilator effect of histamine
-brighter red flush/flare extending 1 cm beyond the initial red spot and developing more slowly
-flare is caused by histamine-induced stimulations of axon reflexes that cause vasodilatation indirectly
-wheal (a sudden formed elevation of the skin surface) is noticeable in 1-2 minutes
-wheal occupies the same area as the original red spot at the site of injection results from the histamine’s capacity to increase capillary permeability 
Lösung ausblenden
TESTE DEIN WISSEN
What is histamines mechanism of action?
Lösung anzeigen
TESTE DEIN WISSEN
Produces its action by acting on three main types of histamine receptors

 

H1

Located mainly on smooth muscles of GI tract, lungs, uterus, blood vessels, sensory nerve endings and in CNS.

H2

Parietal cells of gastric mucosa, heart etc.

H3

H4

Presynaptic terminals of histaminergic neurones in CNS and GI tract that regulate release of histamine and other transmitters

Not well characterised yet

Lösung ausblenden
TESTE DEIN WISSEN
What are the actions of the prostanoids?
Lösung anzeigen
TESTE DEIN WISSEN
–PGD2 causes vasodilatation, relaxation of GI and uterine smooth muscles by acting on DP (prostaglandin) receptors
–PGI2 causes vasodilatation, inhibition of platelet aggregation, renin release and natriuresis by acting on prostaglandin IP receptors
–Thromboxane A2 causes vasoconstriction and platelet aggregation by acting on thromboxane (TP) receptors
–PGF2a causes myometrial contraction (FP receptors)
–PGE2 causes contraction of bronchial and GI smooth muscles by acting on prostaglandin EP1 receptors & activating them 
-PGE2 causes bronchodilation, vasodilatation, relaxation of GI smooth muscles on prostaglandin EP2 receptors & activating them
-PGE2 causes increased gastric mucus secretion and decrease acid secretion, contraction of GI smooth muscles, contraction of pregnant human uterus y acting on EP3 receptors & activating them 
•The synthesis of mainly PGE2 in hypothalamus in response to pyrogens (substances that cause fevers)
- PGE2 and others are G-coupled receptors 
Lösung ausblenden
TESTE DEIN WISSEN
What is the role of the prostanoids in inflammation?
Lösung anzeigen
TESTE DEIN WISSEN
–PGE2, PGI2 and PGD2 are vasodilators
– increase in vascular permeability due to other mediators of inflammation
– pain produced by bradykinin
–Synthesis of PGE2 in hypothalamus in response to endogenous pyrogens leads to fever
–Prostanoids have an anti-inflammatory modulatory role on immunocytes
Lösung ausblenden
TESTE DEIN WISSEN
What are the clinical applications of agonists?
Lösung anzeigen
TESTE DEIN WISSEN
•Agonists
–Medical abortion (gemeprost, misoprostol PGE analogue)
–Gastric cytoprotection (misoprostol)
–Impotence  (alprostadil PGE1)
–Inhibit platelet aggregation during haemodialysis (epoprostenol PGI2)
–Glaucoma (latanoprost)
Lösung ausblenden
TESTE DEIN WISSEN
How is histamine released?
Lösung anzeigen
TESTE DEIN WISSEN
-Released from mast cells during inflammatory and allergic reaction
-Due to Interaction of antigens with cell-fixed Ige antibodies
-And communication of c3a and c5a with their receptors
-Secretion is linked to a rise in cytosolic calcium ion concentration
Lösung ausblenden
  • 7162 Karteikarten
  • 259 Studierende
  • 12 Lernmaterialien

Beispielhafte Karteikarten für deinen Autocoids Kurs an der University of Bradford - von Kommilitonen auf StudySmarter erstellt!

Q:
What are eicosanoids?
A:
•Lipid autocoids derived from membrane phospholipids
–Prostanoids
–Leukotrienes
•Eicosanoids, unlike histamine, are not stored preformed in the tissues; they are generated as required from membrane phospholipids
Q:
What are cyclooxygenase enzymes?
A:
-Two forms of cyclooxygenase exist in the body
-COX-1 occur in most cells as a constitutive enzyme
-COX-2 is induced mainly in inflammatory cells by an inflammatory stimulus
•COX-2 selective inhibitors (Coxibs) are now available such as Celecoxib, etoricoxib,  which cause less GI side effects
Q:
What are the actions of histamine and the related receptors?
A:
•Vasodilatation - H1 receptors
•Increases capillary permeability - H1 receptors
Contraction of ileal smooth muscles  - H1 receptors
•Contraction of bronchial smooth muscles - H1 receptors
•Itch and pain due to stimulation of nerve endings - H1 receptors
•Gastric acid secretion  - H2 receptors
•Increases heart rate & output -H2 receptors
Q:
What are type 1 hypersensitivity reactions?
A:
•Histamine is the first mediator to be released in allergic reactions
-responsible for many signs of inflammation. 
• acting on H1 receptors
Q:
How is gastric acid secreted and how can consequential conditions be treated?
A:
•Histamine provide one of the stimulus to gastric parietal cells to secrete HCl. 
•Conditions, such as Gastro-oesophageal Reflux Disease (GORD), peptic and duodenal ulcers
-conditions are caused by excessive gastric acid secretion 
-can be treated with  H2 receptor antagonists
Mehr Karteikarten anzeigen
Q:
What histamine antagonists are available and their features ?
A:
•H1-receptor antagonists known as antihistamines
•Older antihistamines (1st generation) cause sleepiness and less safe unlike 2nd generation antihistamines which interact with other medications better hence its safer to use
Non-sedating antihistamines: Terfenadine
–Used to treat hay fever (seasonal rhinoconjunctivitis) and urticaria.
•Reduce rhinorrohea, sneezing and pruritus.
•Other uses: sedative, anti-emetic, antitussive
–administered orally but can be given by injection or topically
H2-receptor antagonists such as Cimetidine
–Used to decrease gastric acid secretion which 
•Helps heal peptic and duodenal ulcers
•Gastro-oesophageal reflux disease
–Less effective than Proton Pump Inhibitors (e.g. omeprazole) but have prominent effects on basal acid secretion and suppress nocturnal acid secretion.
Q:
What is the triple response to histamine?
A:
-triple response is caused by intradermal injection of histamine
- red spot extending few mms, appears within a few seconds and reach maximum in about a minute
- red spot caused from the direct vasodilator effect of histamine
-brighter red flush/flare extending 1 cm beyond the initial red spot and developing more slowly
-flare is caused by histamine-induced stimulations of axon reflexes that cause vasodilatation indirectly
-wheal (a sudden formed elevation of the skin surface) is noticeable in 1-2 minutes
-wheal occupies the same area as the original red spot at the site of injection results from the histamine’s capacity to increase capillary permeability 
Q:
What is histamines mechanism of action?
A:
Produces its action by acting on three main types of histamine receptors

 

H1

Located mainly on smooth muscles of GI tract, lungs, uterus, blood vessels, sensory nerve endings and in CNS.

H2

Parietal cells of gastric mucosa, heart etc.

H3

H4

Presynaptic terminals of histaminergic neurones in CNS and GI tract that regulate release of histamine and other transmitters

Not well characterised yet

Q:
What are the actions of the prostanoids?
A:
–PGD2 causes vasodilatation, relaxation of GI and uterine smooth muscles by acting on DP (prostaglandin) receptors
–PGI2 causes vasodilatation, inhibition of platelet aggregation, renin release and natriuresis by acting on prostaglandin IP receptors
–Thromboxane A2 causes vasoconstriction and platelet aggregation by acting on thromboxane (TP) receptors
–PGF2a causes myometrial contraction (FP receptors)
–PGE2 causes contraction of bronchial and GI smooth muscles by acting on prostaglandin EP1 receptors & activating them 
-PGE2 causes bronchodilation, vasodilatation, relaxation of GI smooth muscles on prostaglandin EP2 receptors & activating them
-PGE2 causes increased gastric mucus secretion and decrease acid secretion, contraction of GI smooth muscles, contraction of pregnant human uterus y acting on EP3 receptors & activating them 
•The synthesis of mainly PGE2 in hypothalamus in response to pyrogens (substances that cause fevers)
- PGE2 and others are G-coupled receptors 
Q:
What is the role of the prostanoids in inflammation?
A:
–PGE2, PGI2 and PGD2 are vasodilators
– increase in vascular permeability due to other mediators of inflammation
– pain produced by bradykinin
–Synthesis of PGE2 in hypothalamus in response to endogenous pyrogens leads to fever
–Prostanoids have an anti-inflammatory modulatory role on immunocytes
Q:
What are the clinical applications of agonists?
A:
•Agonists
–Medical abortion (gemeprost, misoprostol PGE analogue)
–Gastric cytoprotection (misoprostol)
–Impotence  (alprostadil PGE1)
–Inhibit platelet aggregation during haemodialysis (epoprostenol PGI2)
–Glaucoma (latanoprost)
Q:
How is histamine released?
A:
-Released from mast cells during inflammatory and allergic reaction
-Due to Interaction of antigens with cell-fixed Ige antibodies
-And communication of c3a and c5a with their receptors
-Secretion is linked to a rise in cytosolic calcium ion concentration
Autocoids

Erstelle und finde Lernmaterialien auf StudySmarter.

Greife kostenlos auf tausende geteilte Karteikarten, Zusammenfassungen, Altklausuren und mehr zu.

Jetzt loslegen

Das sind die beliebtesten Autocoids Kurse im gesamten StudySmarter Universum

authors

All India Institute of Medical Sciences

Zum Kurs
Automne 2022

Université Laval

Zum Kurs
FDP-autores

Universidade Catolica Portuguesa

Zum Kurs
AUTOESCOLA

Universidade Federal de Viçosa

Zum Kurs
AUTACOIDES

Universitat de Barcelona

Zum Kurs

Die all-in-one Lernapp für Studierende

Greife auf Millionen geteilter Lernmaterialien der StudySmarter Community zu
Kostenlos anmelden Autocoids
Erstelle Karteikarten und Zusammenfassungen mit den StudySmarter Tools
Kostenlos loslegen Autocoids