Prostanoids mechanisms

Free radicals are by-products of prostaglandin metabolism and may even regulate the activity of the arachidonate pathway. Arachidonic acid, released from lipids as a result of activation of phospholipases by tissue injury or by hormones, may be metabolized by the prostaglandin or leu-kotriene pathways. The peroxidase-catalysed conversion of prostaglandin G2 to prostaglandin H2 (unstable prostanoids) and the mechanism of hydroperoxy fatty acid to the hydroxy fatty acid conversion both yield oxygen radicals, which can be detected by e.s.r. (Rice-Evans et al., 1991). 

Samad, T. A., Sapirstein, A. and Woolf, C. J. Prostanoids and pain unraveling mechanisms and revealing therapeutic targets. Trends Mol. Med. 8 390-396,2002. 

Mechanism of Action An ophthalmic agent that is a prostanoid selective FP receptor agonist. Therapeutic Effect Reduces intraocular pressure (lOP) by reducing aqueous humor production. 

A number of drug substances are known to act directly upon the uterus, including uterine relaxants (e.g., (3-agonists) and stimulants (e.g., prostanoids, oxytocin). The administration of drugs to the uterus is achieved by the application of a formulated product to the vagina or the cervix. However, it has been demonstrated that the mechanism by which the drug is transported from the cervicovagina to the uterus is not limited to passive diffusion, but is facilitated by a preferential transport mechanism termed as the first uterine pass effect. 

Chintakunta VK, Akella V, Vedula MS et aL (2002) 3-0-Substituted benzyl pyrazidone derivatives as COX inhibitors. Eur J Med Chem 37 339-347 Coleman RA, Smith WL, Narumiya S (1994) VIII. International union of pharmacology classification of prostanoid receptors Properties, distribution, and structure of the receptors and their subtypes. Pharmacol Rev 46 205-229 Copeland RA, Williams JM, Giannaras J et al. (1994) Mechanism of selective inhibition of the inducible isoform of prostaglandin G/H synthase. Proc Natl Acad Sd USA 91 11202-11206... 

Antipyretic analgesics represent p-ami-nophenol or pyrazolone derivatives with clinically useful analgesic and antipyretic efficacy. Their mechanism of action is not completely understood but thought to be mediated via inhibition of prostanoid formation by variants of COX enzymes. Acetaminophen (paracetamol), phenazone, and dipyrone belong in this group. 

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