Document Detail


PGH synthase isoenzyme selectivity: the potential for safer nonsteroidal antiinflammatory drugs.
MedLine Citation:
PMID:  8357002     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
With the recent cloning of a second gene coding for the prostaglandin endoperoxide (PGH) synthase (cyclooxygenase), it has become obvious that mammalian cells contain two related, but unique, isozymes of PGH synthase. Both of these isozymes catalyze the conversion of arachidonic acid to PGH2, leading to production of biologically active prostaglandins. Although the first of these isozymes, PGH synthase-1 (PGHS-1), has long been thought to be the primary and sole site of action of nonsteroidal antiinflammatory drugs (NSAIDs), it is now known that the second isozyme, PGH synthase-2 (PGHS-2), is also sensitive to NSAIDs. Cloning of complementary DNAs for murine PGHS-1 and PGHS-2 has permitted individual expression of these two isozymes in the cos-1 cell system and comparison of their relative inhibition by several common NSAIDs in vitro. These studies have demonstrated that the two mouse isozymes, PGHS-1 and PGHS-2, are pharmacologically distinct. PGHS-1 is a constitutively expressed enzyme that early observations indicate is the principal enzyme involved in producing prostaglandins that regulate cellular housekeeping functions, such as gastric cytoprotection, vascular homeostasis, and kidney function. In contrast, PGHS-2 appears only to be expressed in inflamed tissue or following exposure to growth factors, lymphokines, or other mediators of inflammation. Expression of PGHS-2 is inhibited by antiinflammatory glucocorticoids, lending further support to the hypothesis that this enzyme produces prostaglandins involved in inflammation. We have identified NSAIDs that preferentially inhibit murine PGHS-1 or PGHS-2 or inhibit both isozymes equally. The finding that the two isozymes can be differentially inhibited provides a possible mechanism for identifying safer, more effective NSAIDs. Screening for drugs that preferentially inhibit PGHS-2 may allow identification of NSAIDs that reduce inflammation, but spare renal and gastric prostaglandin synthesis, thus reducing the untoward side effects commonly associated with most NSAIDs. Thus far, nabumetone is the only NSAID identified that preferentially inhibits murine PGHS-2.
Authors:
D L DeWitt; E A Meade; W L Smith
Publication Detail:
Type:  Journal Article; Review    
Journal Detail:
Title:  The American journal of medicine     Volume:  95     ISSN:  0002-9343     ISO Abbreviation:  Am. J. Med.     Publication Date:  1993 Aug 
Date Detail:
Created Date:  1993-09-23     Completed Date:  1993-09-23     Revised Date:  2005-11-17    
Medline Journal Info:
Nlm Unique ID:  0267200     Medline TA:  Am J Med     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  40S-44S     Citation Subset:  AIM; IM    
Affiliation:
Department of Biochemistry, Michigan State University, East Lansing 48824-1319.
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MeSH Terms
Descriptor/Qualifier:
Animals
Anti-Inflammatory Agents, Non-Steroidal / pharmacology*
Cyclooxygenase Inhibitors / pharmacology
Humans
Isoenzymes / drug effects,  metabolism*
Prostaglandin-Endoperoxide Synthases / drug effects,  metabolism*
Chemical
Reg. No./Substance:
0/Anti-Inflammatory Agents, Non-Steroidal; 0/Cyclooxygenase Inhibitors; 0/Isoenzymes; EC 1.14.99.1/Prostaglandin-Endoperoxide Synthases

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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