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.
D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology; D001792:Blood Platelets / Q000502:physiology*; D004731:Endotoxins / Q000494:pharmacology*; D011464:Epoprostenol / Q000494:pharmacology; D005260:Female; D006168:Guinea Pigs; D006493:Heparin / Q000494:pharmacology; D016285:Iloprost; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D008168:Lung / Q000166:cytology*; D008297:Male; D010972:Platelet Activating Factor / Q000502:physiology*
D000889:Anti-Arrhythmia Agents; D004731:Endotoxins; D010972:Platelet Activating Factor; D006493:Heparin; D011464:Epoprostenol; D016285:Iloprost; D007213:Indomethacin