What are COX-1 and COX-2 pathways?

What are COX-1 and COX-2 pathways?

Cyclooxygenases (COX-1 and COX-2) are key enzymes in the conversion of arachidonic acid to prostaglandins and other lipid mediators. Because it can be induced by inflammatory stimuli, COX-2 has been classically considered as the most appropriate target for anti-inflammatory drugs.

What is the COX-1 pathway?

COX pathway of arachidonic acid metabolism. COX-1 or COX-2 converts arachidonic acid to PGG2 and furthermore to PGH2 via COX and peroxidase activity. PGH2 is next metabolized to 5 major bioactive prostanoids—PGE2, PGI2, PGD2, PGF2, and TXA2—through their respective tissue-specific synthases.

What do COX-1 COX-2 and COX-1 COX-2 denote?

The enzymes cyclooxygenase-1 and cyclooxygenase-2 (COX-1 and COX-2) catalyze the conversion of arachidonic acid to prostaglandin (PG) H2, the precursor of PGs and thromboxane. These lipid mediators play important roles in inflammation and pain and in normal physiological functions.

Where are COX-1 and COX-2 receptors located?

COX-1 is found in platelets, GI mucosal cells, and renal tubule cells. COX-2 has been identified in fibroblasts, chondrocytes, endothelial cells, macrophages, and mesangial cells. COX-2 is induced by exposure to various cytokines, mitogens and endotoxin, and it is up-regulated at inflammation sites.

What activates COX-2?

By contrast, the gene for COX-2, Ptgs-2, is an immediate early gene that is activated by a wide variety of inflammatory and proliferative stimuli, and the 4 kb COX-2 mRNA turns over rapidly due to the presence of instability sequences in the 3′-untranslated region (1, 2).

What is cyclooxygenase and lipoxygenase?

Cyclooxygenase- and lipoxygenase-catalyzed arachidonic. acid metabolism. Two major metabolic routes, i.e., the COX and LOX pathways, control the biosynthesis of eicosanoids.

What does COX-1 do in the body?

COX-1 is known to be present in most of the tissues in your body. In the gastrointestinal tract, COX-1 maintains the normal lining of the stomach and intestines, protecting the stomach from the digestive juices. 4 The enzyme is also involved in kidney and platelet function.

What is thromboxanes function?

Thromboxanes, a substance produced by platelets, lead to occlusion of blood vessels by fueling blood clots inside the vascular system. This has been implicated in many cardiovascular conditions, ranging from hearth attack to stroke.

Are prostacyclins and prostaglandins the same?

Prostacyclin (also called prostaglandin I2 or PGI2) is a prostaglandin member of the eicosanoid family of lipid molecules. It inhibits platelet activation and is also an effective vasodilator. When used as a drug, it is also known as epoprostenol. The terms are sometimes used interchangeably.

What happens when COX-1 is inhibited?

Cox-1 inhibitors can reduce inflammation, but they may also decrease the natural protective mucus lining of the stomach. Therefore, these medications can cause stomach upset, intestinal bleeding, and ulcers. In some cases, using a buffered form of a cox-1 inhibitor can eliminate or reduce these adverse effects.

What does COX-2 do in the body?

In contrast, COX-2, the inducible form, is expressed in response to inflammatory and other physiologic stimuli and growth factors and is involved in the production of those prostaglandins that mediate pain and support the inflammatory process.

Does COX-1 produce prostacyclin?

Within large arteries, both endothelial cells (ECs) and smooth muscle cells (SMCs) can produce prostacyclin, although the endothelium is assumed to be the dominant site. COX1 drives prostacyclin release in freshly isolated arteries and circulating levels of prostacyclin’s spontaneous breakdown product (6-ketoPGF1α).