Autocoids & Inflammation Flashcards
What are autocoids?
Biological factors that act like local hormones. They have a brief duration and act near the site of synthesis
How is a normal hormone e.g. testosterone different to a local hormone e.g. histamine, kinins or ecosanoids?
Local hormones act near the site of synthesis, where as normal hormones e.g. testosterone, is made in the testes but travels to the brain and acts there.
Give three types of local hormones
- histamines
- kinins
- ecosanoids
What are some examples of ecosanoids?
Prostaglandins, leukotreines and PAF (platelet activating factor)
Econasoids can cause the signs of ________.
The cardinal signs of inflammation include:
-
-
-
-
-
inflammation rubor tumor calor dolor functio laesa
What do the following mean functio laesa calor tumor rubor dolor
loss of function heat inflammation/ swelling redness pain
Does inflammation always involve immunity?
NO
Does inflammation always involve immunity? What else could it be due to?
NO. Trauma: heat, radiation
What are the two reasons for inflammation
Trauma - heat, radiation
Immunity
What are the 4 types of immunological reactions?
Type 1 - anaphylaxis or allergy e.g. hay-fever
Type 2 - Antibody dependent cytotoxicity
Type 3 - complex mediated hypersensitivity e.g rheumatoid arthritis
Type 4 - cell mediated hypersensitivity e.g. T cell mediated (when you get checked for TB)
What is histamine made from? What is it important for? Where is it stored? Where can it be made on demand? What is it caused to be released by?
Histidine which is a basic amino acid. Inflammation Stored in structures called granules in either mast cells (found in tissues) or basophils (found in blood. Gastric mucosa It is released by allergens
Mast cells are found where in the body?
It contains dense structures called ______.
Granules are packed full of _____ coupled to _____
Tissues, especially in epithelium e.g gut wall, nasal epithelium
granules
histamine
heparin
When allergen comes into contact with mast cell, mast cell instantly breaks and histamine and heparin are released from the granules, If too much histamine or heparin (causes bruising) is released due to an ALLERGY (e.g anaphylactic shock), what will happen to blood pressure? Which organs does this affect
blood pressure falls dramatically.
brain
heart
kidney
After anaphylactic shock, how do you increase blood pressure?
Inject adrenaline/epinephrine
Which antibody coats the mast cell for it to detect the allergen?
IgE
In order for a histamin+heparin reaction to occur, what must happen?
the allergen MUST cross link with the IgE antibody
What causes histamines to be released?
- Allergen cross linking with IgE antibody
- Trauma
- Side effect of drugs such as morphine, 48/80 and D-tubocurarine
People with respiratory problems e.g asthma/COPD are not usually given drugs (with histamine release occurring as a side effect) during surgery as it will aggravate
their respiratory conditions (vasodilation)
What do mast cells release?
histamines kallikrein leukotreines prostaglandin D2 PAF TNF alpha
Treatment of allergy include:
Give an example of each
- Antihistamines (H1 receptor blockers) e.g. mepyramine
- Mast cell stabilisers e.g. disodium cromoglycate or ketotifen
How do antihistamines work?
By blocking the H1 receptor ( 7TM G protein coupled receptor)
What ares some sedating antihistamines
promethazine
mepyramine
What is a non sedating antihistamine? Why is it non sedating?
Cetirizine
Crosses the BBB less
kinins are peptide mediators that are synthesised by _____ and metabolised by _____
kininogen
kinases
