Inflammation

Question 1

Acute inflammation

Answer 1

Occurs after tissue damage due to release of mediators

Stimulates repair and prevents further damage

Signs = heat, redness, swelling, pain, loss of function

Question 2

Histamine

Answer 2

Released from mast cells during inflammatory or allergic reactions

Stimulated by a rise in cytosolic calcium ions

Receptors are all GPCRs (H1-4)

Question 3

Effects of histamine

Answer 3

• Smooth muscle contraction
• Blood vessel dilation
• Increases cardiac output
• Stimulates gastric secretion
• Itching

Question 4

Prostaglandins

Answer 4

Synthesised from phospholipids in the arachidonic acid pathway

Rate limiting step = phospholipase A2

COX enzymes then convert arachidonic acid into prostaglandins

Prostaglandin receptors are all GPCRs

Question 5

COX1 enzymes

Answer 5

Present in most cells and platelets

Help prostaglandins to contribute to homeostasis

Important for producing PGE2 in the stomach

Small hydrophobic channel

Question 6

COX2 enzymes

Answer 6

Not normally present in most tissues

Strongly induced by inflammatory stimuli

Larger hydrophobic channel

Question 7

Bradykinin

Answer 7

Produced by the kinin cascade

Causes vasodilation and increased vascular permeability

Induces pain

Question 8

Leukotrienes

Answer 8

Produced from arachidonic acid via the lipoxygenase pathway

Rate limiting enzymes = 5-lipoxygenase & FLAP

convert arachidonic acid into leukotriene A4

All receptors are GPCRs