In vivo responses of mouse blood cells to platelet-activating factor (PAF): role of the mediators of anaphylaxis.
Intravenous injection of platelet-activating factor (PAF) (0.36 mumol/kg b.w.) in mice induced severe hemoconcentration, leucopenia, thrombocytopenia and finally the death of 85% of the tested animals. Combined inhibition of histamine and serotonin by promethazine and chlorpromazine, 6.24 and 3.12 mg/kg b.w. subcutaneously, protected the mice from PAF in part, reducing the death rate to 43%. These drugs did not protect the mice against the PAF-induced hemoconcentration, leucopenia and thrombocytopenia. Sulfinpyrazone (100 mg/kg b.w.) intravenously was the most effective both in protecting mice from PAF-induced death, reducing the death rate to 17%, and from thrombocytopenia, although hemoconcentration persisted. These results indicated that an important component of the PAF-induced systemic effects is mediated by reactions which can be inhibited by sulfinpyrazone. Furthermore, PAF-induced thrombocytopenia is not a direct PAF effect since it can be inhibited by sulfinpyrazone.
Institute of Biology, N.C.S.R., Demokritos, Attiki, Greece.
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Kelefiotis
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Vakirtzi-Lemonias
D000707:Anaphylaxis / Q000503:physiopathology*; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D001773:Blood Cells / Q000187:drug effects*; D002746:Chlorpromazine / Q000494:pharmacology; D004906:Erythrocyte Count / Q000187:drug effects; D006633:Histamine Antagonists / Q000494:pharmacology; D007958:Leukocyte Count / Q000187:drug effects; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D010972:Platelet Activating Factor / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D010976:Platelet Count / Q000187:drug effects; D011398:Promethazine / Q000494:pharmacology; D012702:Serotonin Antagonists / Q000494:pharmacology; D013442:Sulfinpyrazone / Q000494:pharmacology
D000894:Anti-Inflammatory Agents, Non-Steroidal; D006633:Histamine Antagonists; D010972:Platelet Activating Factor; D012702:Serotonin Antagonists; D011398:Promethazine; D002746:Chlorpromazine; D013442:Sulfinpyrazone