What is the difference between COX-1 and COX-2?

What is the difference between Cyclooxygenase-1 (COX-1) and Cyclooxygenase-2 (COX-2)?

by: Arlene Gentallan

Cyclooxygenase (COX) is an enzyme that plays a key role in the formation of prostanoids such as prostaglandins, prostacyclin and thromboxane--which are involve in inflammatory response (pain, swelling, redness, increase heat, and loss of function.) Prostaglandins are formed from arachidonic acid.

What is the difference between COX-1 and COX-2?

Cyclooxygenase-1 (COX-1):

        Presence in the body: It is produced at a constant rate by the body for it's normal functioning.


  • Regulates gastric acidity
  • Protects the gastrointestinal mucosa
  • Regulates water secretion by the kidneys
  • Blood clotting.
  • COX-1 is involve in the production of prostaglandin that is essential for the everyday functioning.

        Location: Predominantly found in the stomach, kidneys, and platelets.

Cyclooxygenase-2 (COX-2):

        Presence in the body: Not usually present in the body unless triggered by the immune system.

        Purpose: Responsible for the production of prostaglandin which is involve in inflammation, pain, and fever.

        Location: Commonly located at macrophages, leukocytes and fibroblasts at the site of inflammation.

Cyclooxygenase-1 (COX-1) is important to maintain the function of body organs such as stomach, kidneys, and platelet; while Cyclooxygenase-2 (COX-2) is primarily involve with inflammation and pain.