1-[4-[3-[4-[bis(4-fluorophenyl)hydroxymethyl]-1- piperidinyl]propoxy]-3-methoxyphenyl]ethanone(AHR-5333): a selective human blood neutrophil 5-lipoxygenase inhibitor.
In this study we report the in vitro inhibition of leukotriene synthesis in calcium ionophore (A23187)-stimulated, intact human blood neutrophils by AHR-5333. The results showed that AHR-5333 inhibits 5-HETE, LTB4 and LTC4 synthesis with IC50 values of 13.9, 13.7 and 6.9 microM, respectively. Further examination of the effect of AHR-5333 on individual reactions of the 5-lipoxygenase pathway (i.e. conversion of LTA4 to LTB4, LTA4 to LTC4, and arachidonic acid to 5-HETE) showed that this agent was not inhibitory to LTA4 epoxyhydrolase and glutathione-S-transferase activity in neutrophil homogenates. However, conversion of arachidonic acid (30 microM) to 5-HETE was half maximally inhibited by 20 microM AHR-5333 in the cell-free system. The inhibition of LTB4 and LTC4 formation in intact neutrophils by AHR-5333 appears to be entirely due to a selective inhibition of 5-lipoxygenase activity and an impaired formation of LTA4, which serves as substrate for LTA4 epoxyhydrolase and glutathione-S-transferase. AHR-5333 did not affect the transformation of exogenous arachidonic acid to thromboxane B2, HHT and 12-HETE in preparations of washed human platelets, indicating that this agent has no effect on platelet prostaglandin H synthase, thromboxane synthase and 12-lipoxygenase activity. The lack of inhibitory activity of AHR-5333 on prostaglandin H synthase activity was confirmed with microsomal preparations of sheep vesicular glands.
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Department of Molecular Biology, A.H. Robins Company, Research Laboratories, Richmond, Virginia 23261-6609.
Anderson
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D000818:Animals; D001094:Arachidonate 5-Lipoxygenase / Q000097:blood; D001091:Arachidonate Lipoxygenases / Q000037:antagonists & inhibitors*; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000097:blood; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids / Q000096:biosynthesis; D066298:In Vitro Techniques; D007975:Leukotriene B4 / Q000096:biosynthesis; D016859:Lipoxygenase Inhibitors; D008861:Microsomes / Q000201:enzymology; D009504:Neutrophils / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D010880:Piperidines / Q000494:pharmacology*; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D013189:SRS-A / Q000096:biosynthesis; D012756:Sheep
D001095:Arachidonic Acids; D006893:Hydroxyeicosatetraenoic Acids; D016859:Lipoxygenase Inhibitors; D010880:Piperidines; D013189:SRS-A; D007975:Leukotriene B4; D016718:Arachidonic Acid; C022022:5-hydroxy-6,8,11,14-eicosatetraenoic acid; C055541:AHR 5333; D001091:Arachidonate Lipoxygenases; D001094:Arachidonate 5-Lipoxygenase; D011451:Prostaglandin-Endoperoxide Synthases