Cyclooxygenase-1 variant (COX-3) (COX-3)

The central cyclooxygenase variant, commonly referred to as COX-3, is an alternative splice variant of the COX-1 (PTGS1) gene that retains intron 1 in its mRNA (Simmons et al., 2002, PNAS). It was first identified in canine brain tissue and proposed as the primary molecular target for acetaminophen (paracetamol), explaining the drug's ability to reduce pain and fever without significant peripheral anti-inflammatory effects (Chandrasekharan et al., 2002, PNAS). COX-3 is predominantly expressed in the cerebral cortex and heart, where it facilitates the synthesis of prostaglandins that modulate central pain signaling and thermoregulation. However, its role in human physiology remains a subject of intense debate because the human COX-3 mRNA contains a frame-shift mutation that typically results in a truncated, potentially non-functional protein (Schwab et al., 2003, Lancet). Despite these controversies, the enzyme remains a key pharmacological concept for understanding the central actions of antipyretic analgesics and continues to be studied as a potential target for novel pain therapies.

Other names

COX-1bCOX-1vProstaglandin-endoperoxide synthase 1 variantCentral cyclooxygenasePCOX-1a

Inhibition of prostaglandin synthesis within the central nervous system by targeting a specific splice variant of the COX-1 enzyme, thereby reducing the production of pro-pyretic and pro-nociceptive mediators like PGE2.