Cox Enzyme Research Paper

There are COX enzyme isoforms include COX-1 and COX-2. (Figure 3.8) These enzymes originate from different genes and have distinct tissue-specific expressions and biologic functions. COX-1 is constitutively expressed in most tissues and believed to responsible for the production of prostanoids in homeostasis, such as gastric epithelial cytoprotection and renal blood flow maintenance. COX-2 expression is inducibly expressed only at marginal levels under condition in many tissues and is upregulated in response to a variety of stimuli, pro-inflammatory, hormones and growth factors as well as associated with inflammation and disease states. Its pivotal role in the production of prostanoids during inflammation and in cancerous states provided the rationale for the development of COX-2 selective NSAIDs.57-59
Next, an endoperoxidase reaction reduces PGG2 to PGH2. Terminal PG synthases then convert PGH2 into prostanoids; PGD2 by hematopoietic PGD synthase; PGI2 by PGI synthase; PGE2 by micorsomal PGE synthase (mPGES)-1, mPGES-2 or cytosolic PGES; PGF2a by PGF synthase; and thromboxane A2 (TXA2) by thromboxane synthase. The prostanoids act on specific G-protein-coupled receptors including two PGD2 receptors (DP1 and DP2), one PGI2 receptor (IP), four PGE2 receptor subtypes (EP1, EP2, EP3, and EP4), one PGF2a receptor (FP) and one TXA2 receptor