it into an inactive compound. The enzymes within this family are lipoprotein-associated phospholipase A2, cytoplasmic platelet-activating factor acetylhydrolase 2, and platelet-activating factor acetylhydrolase 1b. Cations are one form of regulation in the production of PAF. Calcium plays a large role in the inhibition of enzymes that produce PAF in the denovo pathway of PAF biosynthesis. The regulation of PAF is still not completely understood. Enzymes that are associated with the production of PAF are controlled by metal ions, thiol compounds, fatty acids, pH, compartmentalization, and phosphorylation and dephosphorylation. These controls on these PAF producing enzymes are believed to work in conjunction to control it, but the overall pathway and reasoning is not well understood. Pharmacology Inhibition PAF antagonists do not provoke an inflammatory response upon binding, but block or lessen the effect of PAF. Examples of PAF antagonists are: CV-3988 is a PAF antagonist that blocks signaling events correlated to the expression and binding of PAF to the PAF Receptor. SM-12502 is a PAF antagonist, which is metabolized in the liver by the enzyme CYP2A6. Rupatadine is an antihistamine and PAF antagonist used to treat allergies. Etizolam is a benzodiazepine analog and PAF antagonist used to treat anxiety and panic attacks. Apafant Lexipafant (Zacutex) for treatment of pancreatitis. Modipafant A full list in a review: Clinical significance High PAF levels are associated with a variety of medical conditions. Some of these conditions include: •Allergic reactions •Stroke •Sepsis •Myocardial infarction •Colitis, inflammation of the large intestine •Multiple sclerosis While the effects that PAF has on inflammatory response and cardiovascular conditions are well understood, PAF is still a subject for discussion. Over the past 23 years, papers written on PAF have almost doubled from approximately 7,500 in 1997 to 14,500 in 2020. Research into PAF is ongoing. See also Platelet-activating factor receptor Platelet-derived growth factor References External links Srf1 is Essential to Buffer Toxic Effects of Platelet Activating Factor Pharmacorama - PAF (Platelet Activating Factor) Hematology Phosphatidylcholines