Inhibitory effect of arachidonic acid on platelet-activating factor production in rat neutrophils.
Platelet-activating factor production in rat neutrophils in response to opsonized zymosan was suppressed dose dependently in the presence of 10-100 microM arachidonic acid. The amount of lyso-PAF was also reduced by these doses of arachidonic acid. Phospholipase A2 activity was not changed by addition of arachidonic acid up to 100 microM, but acetyltransferase activity was slightly reduced at a 100 microM concentration of arachidonic acid. Pretreatment with indomethacin did not alter the inhibitory effect of arachidonic acid on PAF production, indicating no involvement of cyclooxgenase products. Triacsin C, an acyl-CoA synthetase inhibitor, reversed the arachidonic acid-induced suppression of lyso-PAF and PAF production, suggesting that arachidonic acid might exert its inhibition via the acylation pathway of lyso-PAF to reduce the availability of lyso-PAF.
Naraba
H
H
Department of Pharmacology, School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan.
Ueno
A
A
Matsumoto
H
H
Oh-ishi
S
S
D000101:Acetyl-CoA C-Acetyltransferase / Q000378:metabolism; D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism / Q000494:pharmacology*; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D009504:Neutrophils / Q000187:drug effects* / Q000378:metabolism; D010741:Phospholipases A / Q000378:metabolism; D054467:Phospholipases A2; D010972:Platelet Activating Factor / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014226:Triazenes / Q000494:pharmacology; D015054:Zymosan / Q000494:pharmacology
D016861:Cyclooxygenase Inhibitors; D004791:Enzyme Inhibitors; D010972:Platelet Activating Factor; D014226:Triazenes; D016718:Arachidonic Acid; C034613:triacsin C; D015054:Zymosan; D000101:Acetyl-CoA C-Acetyltransferase; D010741:Phospholipases A; D054467:Phospholipases A2; D007213:Indomethacin