• Two isoforms of COX have been characterized, COX-1 and COX-2. (nih.gov)
  • Observations were made with and without inhibition of constitutive (endothelial constitutive NOS (ecNOS) and COX‐1) and inducible isoforms (iNOS and COX‐2) of NOS and COX. (ersjournals.com)
  • However, these previous studies did not determine the relative contributions of COX (COX‐1 and COX‐2) and nitric oxide synthase (NOS) isoforms (endothelial constitutive (ecNOS) and inducible NOS (iNOS)) to the abnormal acinar microvessel response to HA 4 , 7 . (ersjournals.com)
  • Initial investigations by Miyamoto and Simmons demonstrated that 2 isoforms exist: COX-1 (PTGS-1) and COX-2 (PTGS-2), respectively. (medscape.com)
  • The role of cyclooxygenase (COXs) isoforms in maintaining colonic mucosal integrity is not fully understood. (bvsalud.org)
  • At least two COX isoforms have been identified: COX-1 is predominantly constitutive and expressed in different tissues, such as the stomach, intestine, kidneys and platelets. (bvsalud.org)
  • Upregulation of NOS was assessed by measuring enzyme levels in lung homogenates by Western blot analysis and enhancement of the COX-related pathway was judged from perfusate concentrations of 6‐ketoprostaglandin F 1α . (ersjournals.com)
  • Regardless of the etiology, a deficiency of cyclooxygenase (COX), a key regulatory enzyme in the synthetic pathway of eicosanoid production, results in beneficial and detrimental physiologic conditions relative to imbalances of the eicosanoids. (medscape.com)
  • A decrease in the colonic mucosa integrity in the experimental colitis model can be aggravated only by the inhibition of COX-1, which demonstrated the importance of this enzyme in the maintenance of colonic mucosal integrity. (bvsalud.org)
  • They act by inhibiting the enzyme cyclooxygenase (COX), which promotes the release of prostaglandins, prostacyclins and thromboxanes, and activates phagocytes, which, in turn, promote the release of proinflammatory cytokines in response to tissue trauma. (bvsalud.org)
  • In a previous study, it was demonstrated that HA induces distinct venule dilatation closely associated with vasodilating prostaglandins generated by cyclo-oxygenase (COX), but not by nitric oxide (NO), in intact rat lung 4 . (ersjournals.com)
  • Except for the COX-2 NSAIDs, most have similar adverse effect profiles, and most have the same effect on prostaglandins. (medscape.com)
  • Since their discovery in the mid 1930s as potent bioactive compounds in human semen ( 1 ), prostaglandins and their relatives have fascinated several generations of scientists. (jci.org)
  • COX-2 responds to tissue trauma and produces prostaglandins involved in the inflammatory response and pain mediation 5 . (bvsalud.org)
  • Here we provide evidence that there may be a direct link between inhibition of intestinal cancer growth and selective inhibition of the COX-2 pathway. (nih.gov)
  • The nitric oxide produced by ecNOS attenuated COX‐1 activity in injured arterioles and venules, but carbon dioxide enhanced it, leading to paradoxical dilatation of these microvessels under hypercapnic conditions with ecNOS inhibition. (ersjournals.com)
  • Although a high hydrogen ion concentration was unnecessary for excitation of COX‐1, venule constriction in response to H + was enhanced by COX‐1 inhibition. (ersjournals.com)
  • In another study, it was found that this hypercapnia-associated venule dilatation in intact lungs is significantly attenuated in hyperoxia-injured lungs due to inhibition of COX activity by excessive NO 7 . (ersjournals.com)
  • [ 1 ] Thus, tracing research of the COX pathway is essential to an understanding of COX deficiency, and examining the variable effects of COX inhibition are advantageous. (medscape.com)
  • Inhibition of COX-1 may contribute to NSAID GI toxicity. (medscape.com)
  • Inhibition of COX-1 but not COX-2 significantly decreased TER and increased permeability to fluorescein in the 7th day post- colitis group compared to the sham group. (bvsalud.org)
  • The most important cardiovascular effect of aspirin is mediated by irreversible inhibition of platelet cyclooxigenase-1 (COX-1) resulting in the suppression of thromboxane (TX) A2 production. (escardio.org)
  • Here, we focus on newly uncovered pathways, involving either the cyclooxygenases (COXs) or nonenzymatic chemical transformations, that lead to the formation of bioactive prostanoids and of previously unknown lipid mediators produced by COX-2. (jci.org)
  • Selective cyclooxygenase 2 (COX-2) inhibitors have fewer gastrointestinal adverse effects. (medscape.com)
  • Although increased cost can be a negative factor, the incidence of costly and potentially fatal GI bleeds is clearly less with COX-2 inhibitors than with traditional NSAIDs. (medscape.com)
  • Ongoing analysis of cost avoidance of GI bleeds will further define the populations that will find COX-2 inhibitors the most beneficial. (medscape.com)
  • The purpose of this pilot study was to evaluate the effectiveness of two COX-2 selective non-steroidal anti-inflammatory drugs on pain control after open flap debridement. (bvsalud.org)
  • Therefore, COX - also known as prostaglandin-endoperoxide synthase (PTGS), fatty acid COX, prostaglandin H (PGH) synthase, and EC 1.14.99.1 - is implicated in the production of fever, inflammation, and pain. (medscape.com)
  • Collectively, these landmark discoveries provided initial insight into the COX pathway of arachidonate metabolism. (medscape.com)
  • Advances in genomic analysis have led to a clearer understanding of the COX pathway. (medscape.com)
  • In other rat groups, colonic samples from the sham group and a 7th day post- colitis group were mounted in Üssing chambers with the luminal side exposed to a buffer solution (control), acetylsalicylic acid (ASA), SC-560 (COX-1 inhibitor), or celecoxib ( COX-2 inhibitor ). (bvsalud.org)
  • In the 1990's, NSAIDs that specifically inhibited COX-2 were introduced in the market to minimize gastrointestinal adverse effects associated with common NSAIDs. (bvsalud.org)
  • These compounds are synthesized in vivo through what can now be regarded as the "orthodox" cyclooxygenase pathways, which came to light largely through the work of Sune Bergström, who led a team then based at the Karolinska Institutet in Stockholm. (jci.org)
  • The pathogenesis of AIA has implicated both the lipoxygenase (LO) and the cyclooxygenase (COX) pathways. (medscape.com)
  • At therapeutic concentrations, COX-1 isoenzyme is not inhibited, thus GI toxicity may be decreased. (medscape.com)
  • We evaluated HCA-7 cells which express high levels of COX-2 protein constitutively and HCT-116 cells which lack COX-2 protein. (nih.gov)
  • COX-1 is expressed constitutively and is isolated throughout most cell lines in almost all mammalian tissues. (medscape.com)
  • The association of aspirin sensitivity, asthma, and nasal polyposis was first described by Widal et al [ 1 ] in 1922. (medscape.com)
  • Non-responders with a previous ischemic stroke had a 9-fold increase in recurrent ischemic events in comparison to aspirin responders (1), non-responders among coronary artery patients were about 3 times more likely to die, suffer a myocardial infarction or a cerebrovascular accident (2), and non-responders among peripheral vascular patients had an almost doubled rate of peripheral artery reocclusion after angioplasty (3). (escardio.org)
  • By combining optical platelet aggregation tests with TX production measurements aspirin resistance may be categorised into the pharmacokinetic type, the pharmacodynamic type and "pseudoresistance" where TX-independent mechanisms of platelet aggregation play a major role (Table 1) (7). (escardio.org)
  • and 3) whether the contributions of NOS‐ and COX-related products to abnormal microvessel reactions in IA differ qualitatively from those in HA. (ersjournals.com)
  • The aim of the present study was to compare microvessel responses to hypercapnic and isocapnic acidosis in hyperoxia-injured lungs and to assess the role of constitutive and inducible forms of nitric oxide synthase (NOS) and cyclo-oxygenase (COX). (ersjournals.com)
  • COX-2 is considered an inducible isoenzyme, induced during pain and inflammatory stimuli. (medscape.com)
  • The transcription of COX-1 yields a 2.7-kilobase (kb) messenger ribonucleic acid (mRNA) that encodes a 576-residue, 65-kd protein. (medscape.com)
  • Conversely, the transcription of COX-2 yields a 4.5-kb mRNA that encodes a 70-kd protein with roughly 70-75% homology to the COX-1 protein. (medscape.com)
  • They have been defined as monotropic integral membrane proteins located primarily in the endoplasmic reticulum (COX-1) and the perinuclear envelope (COX-2). (medscape.com)
  • Inhibits primarily COX-2. (medscape.com)
  • Tay and colleagues then localized COX-2 to 1q25.2-q25.3 via fluorescein in situ hybridization. (medscape.com)
  • Pain intensity in G2 was significantly lower than in G3 1 and 3 hours after surgery. (bvsalud.org)
  • A goal of this Perspective is to provide a succinct view of salient findings and historical background in this area necessary for the reader to evaluate the potential importance of the newly uncovered "unorthodox" routes ( 2 - 4 ) initiated via cyclooxygenase (for detailed reviews see refs. (jci.org)
  • This study aimed to evaluate the role of COX-1 and -2 on colonic mucosal integrity in an experimental colitis model. (bvsalud.org)
  • A considerable amount of evidence collected from several different experimental systems indicates that cyclooxygenase-2 (COX-2) may play a role in colorectal tumorigenesis. (nih.gov)
  • Evidence suggests that COX-1 and COX-2 are similar in structure and function but that they exist as 2 distinct enzymatic entities. (medscape.com)
  • In this study, we selected two transformed human colon cancer cell lines for studies on the role of COX-2 in intestinal tumorigenesis. (nih.gov)
  • Role of cyclooxygenases 1 and 2 in the maintenance of colonic mucosal integrity in an experimental colitis model. (bvsalud.org)
  • Funk and co-investigators localized COX-1 to 9q32-q33.3 via somatic hybrid deoxyribonucleic acid (DNA) analysis. (medscape.com)
  • Furthermore, using sequence analysis of human genomic DNA, researchers concluded that the amino acids important for catalysis by COX-1 are conserved and are equally important for catalysis by COX-2. (medscape.com)
  • COX-2 is expressed at high levels in intestinal tumors in humans and rodents. (nih.gov)
  • Scaling and root planing is one of the most common periodontal procedures in clinical practice but there may be pain after the procedure 1 . (bvsalud.org)
  • Most patients (77%) experience pain after scaling and root planing and the mean duration of moderate to intense pain is 6.1 hours 1-2 . (bvsalud.org)
  • The vascular reactivity of pulmonary microvessels, especially acinar microvessels, in response to acidosis induced by either alveolar hypercapnia (hypercapnic acidosis (HA)) or metabolic disturbance (isocapnic acidosis (IA)) is one of the major modulators regulating the distribution of pulmonary blood flow 1 - 4 . (ersjournals.com)