Anti-inflammatory drugs Flashcards
What 4 things occur during an inflammatory response?
- Acute microvascular changes
- Release of inflammatory mediators
- Accumulation of inflammatory cells
- Repair and healing
Name 5 inflammatory mediators (out of 8ish)
- Histamine
- Bradykinin (peptide)
- Nitric oxide
- Eicosanoid (lipid): prostaglandins, leukotrienes
- Neuropeptides (e.g. substance P)
- Cytokines (e.g. IL-1)
- Complement, PAF
What are the names of the vessels involved in the microcirculation?
Arteriole
Capillaries
Venule
What is the arteriole involved in within the microcirculation?
Blood flow changes
What is the venule involved in within the microcirculation?
Oedema formation and cell accumulation
From what substance is histamine formed from?
Histidine (Amino acid)
What 2 cells are major sources of histamine?
Mast cells (in bone marrow) Basophils (WBC in bone marrow)
When would histamine be released?
Released in allergic/hypersensitivity (IgE) responses
What is mediated by H1 receptors?
Increased blood flow
Increased microvascular permeability
Itch
Where are H1 receptors expressed?
Smooth muscles
Vascular endothelial cells
Heart
CNS
What inhibits the action of H1 receptors (antagonists)? (2)
Mepyramine
Chlorpheniramine (drowsiness is side effect)
[Non-sedating ones preferred today]
What are the other names for urticaria?
Hives, welts, nettle rash
Name 3 conditions that involve histamine
Allergy Allergic rhinitis Urticaria Hay fever Skin irritations
What are the roles of sensory nerves? (C and delta) (3)
- Transmit sensory information to CNS/initiate reflexes
- Nociception - pain and itch (processing noxious substances)
- Release neuropeptides: including substance P, CGRP and VIP
What stimulant types are there for sensory nerves? (3)
- Mechanical (pressure)
- Temperature (cold and heat)
- Chemical (mediators & capsaicin(found in chilli peppers))
What subset of sensory nerves mediate itchiness?
5% of afferent C-fibres in skin
What is the conducting velocities of skin itch?
0.5 m/s
1/2 that of normal C-fibres
What can be used to reduce itch?
Anti-histamines
Local anaesthetics
What breaks down Arachidonic acid to make prostaglandins and thromboxanes?
Cyclo-oxygenase
What is produced if arachidonic acid is broken down by lipoxygenase?
Leukotrienes
What are eicosanoids?
They are signalling molecules made by the enzymatic or non-enzymatic oxidation of arachidonic acid
(e.g. prostaglandins)
Leukotrienes are synthesised by which enzyme?
5-lipoxygenase
When may LT antagonists/inhibitors be used?
Asthma
Where are PGE2 and PGI2 released from (2)?
And what do these mediate? (2)
Released from endothelial cells and white blood cells.
They mediate increased blood flow and hyperalgesia (increased sens to pain)
What less potent eicosanoid is released from mast cells?
PGD2 (prostaglandin D2)