Defining the role of COX-2 inhibitors in inflammatory and other diseases

The well-established side effects of drug treatments for inflammatory disease, in particular those of the nonsteroidal antiinflammatory drugs (NSAIDs)--principally gastrointestinal (GI) toxicity--, have become an acute problem. There is now considerable experience with the COX-2 selective NSAIDs, which offer an improved GI side-effect profile. The William Harvey Research Conference held in Porto, Portugal, October 23, 2000, reviewed the history of the use of NSAIDs and discussed the pathological and physiological significance of the COX-2 enzyme while covering topics ranging from assays to measure the COX-2:COX-1 ratio, the structural basis for COX-2 selectivity, potential mechanisms of NSAID-induced gastrointestinal toxicity, preclinical studies, effects of COX-2 inhibitors on the kidney and vascular systems, to the latest clinical results, as well as the potential implication of COX-2 in cancer and Alzheimer's disease.

The involvement of platelet activating factor in endotoxin-induced pulmonary platelet recruitment in the guinea-pig

1 Exposure of conscious guinea-pigs to an aerosol of endotoxin (25-100 micrograms ml-1) resulted in a dose-related, progressive accumulation of platelets in the thoracic region. Accumulation of 111indium oxine labelled erythrocytes was not observed following exposure to an aerosol of endotoxin (50 micrograms ml-1). 2 Pretreatment of guinea-pigs with the selective platelet activating factor (Paf)-antagonists. CV-3988 or brotizolam resulted in a dose-related inhibition of endotoxin-induced pulmonary platelet recruitment. Pretreatment of guinea-pigs with the selective Paf-antagonist BN 52021 resulted in significant inhibition of endotoxin-induced pulmonary platelet recruitment, although the effects of BN 52021 were not dose-related. 3 Pretreatment of guinea-pigs with indomethacin at doses known to inhibit cyclo-oxygenase did not inhibit endotoxin-induced pulmonary platelet recruitment, whereas higher doses of indomethacin produced a reduction in platelet recruitment in the lung. 4 Pretreatment of guinea-pigs with the anticoagulant heparin and the prostacyclin analogue ZK 36374 inhibited endotoxin-induced platelet recruitment. 5 These observations suggest that endotoxin-induced pulmonary platelet recruitment in the guinea-pig is secondary to the release of platelet activating factor, but not to cyclo-oxygenase products of arachidonic acid and may also involve activation of the coagulation cascade.