Study on the metabolism of lyso-platelet activating factor (lyso-PAF) in human paranasal sinus mucosa. The cultured ciliated epithelium can convert lyso-PAF to PAF.
The conversion of lyso-platelet activating factor (lyso-PAF) to PAF in cultured paranasal sinus mucosa obtained from normal human subjects was studied. The PAF concentration in the medium was determined after addition of lyso-PAF. PAF became detectable at 10 minutes after the addition of 10(-8)M lyso-PAF, and reached a maximum concentration (3.25 x 10(-9)M) at 20 minutes. The PAF level then gradually declined to become undetectable at 60 minutes after addition of lyso-PAF. Thus PAF is very unstable having a half-life calculated to be 12.8 minutes with an elimination constant of k = 0.05377 minutes-1. In contrast, lyso-PAF is known to be a stable metabolite of PAF as well as a precursor of PAF. The results obtained from this study suggest that the turnover of lyso-PAF to PAF may play a role in evoking prolonged inflammation in target organs or tissues.
Inoue
H
H
Department of Plastic and Reconstructive Surgery, St. Marianna University School of Medicine, Kawasaki, Japan.
Ganbo
T
T
Hisamatsu
K
K
Ishida
H
H
D002478:Cells, Cultured; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism; D006801:Humans; D009297:Nasal Mucosa / Q000166:cytology / Q000378:metabolism*; D010256:Paranasal Sinuses / Q000166:cytology / Q000378:metabolism*; D010972:Platelet Activating Factor / Q000031:analogs & derivatives* / Q000378:metabolism
C029271:O-deacetyl platelet activating factor; D010972:Platelet Activating Factor