COX-1 true statement?

COX-1 true statement?

• A. It is only expressed in the brain
• B. It is mainly involved in pain sensation
• C. It is involved in GI mucosal protection and platelet function
• D. It is only involved in inflammation

Answer: (C)

COX-1 is a constitutive enzyme that supports baseline physiological functions, distinct from COX-2 which is more tied to inflammation. The best statement about COX-1 is that it helps protect the GI mucosa and supports platelet function. In the stomach, COX-1–derived prostaglandins promote mucus and bicarbonate secretion and maintain mucosal blood flow, helping keep the gastric lining resistant to acid injury. In platelets, COX-1 drives the production of thromboxane A2, which promotes platelet aggregation and vasoconstriction, aiding hemostasis. This contrasts with inflammatory pain pathways, where COX-2 tends to be more prominently involved because it is inducible during inflammation. Also, COX-1 is not limited to the brain; it is expressed in many tissues, including the gastric mucosa and platelets, underscoring why nonselective NSAIDs can cause GI side effects and why aspirin has antiplatelet effects through COX-1 inhibition.

COX-1 is a constitutive enzyme that supports baseline physiological functions, distinct from COX-2 which is more tied to inflammation. The best statement about COX-1 is that it helps protect the GI mucosa and supports platelet function. In the stomach, COX-1–derived prostaglandins promote mucus and bicarbonate secretion and maintain mucosal blood flow, helping keep the gastric lining resistant to acid injury. In platelets, COX-1 drives the production of thromboxane A2, which promotes platelet aggregation and vasoconstriction, aiding hemostasis.

This contrasts with inflammatory pain pathways, where COX-2 tends to be more prominently involved because it is inducible during inflammation. Also, COX-1 is not limited to the brain; it is expressed in many tissues, including the gastric mucosa and platelets, underscoring why nonselective NSAIDs can cause GI side effects and why aspirin has antiplatelet effects through COX-1 inhibition.