Turn-over of PAF in cultures of human paranasal sinus mucosa.

The change of PAF concentration in the culture medium was investigated by radioimmunoassay when 10(-8) M PAF or 10(-8) M lyso-PAF was incubated with a piece of normal human paranasal sinus mucosa. The PAF concentration in the medium of the former group was halved within 11.3 min and reduced to less than 5% of the initial concentration within 60 min. However, there was no significant difference in the reduction of PAF concentrations in the medium between groups with or without the mucosa. When 10(-8) M lyso-PAF was incubated with a piece of mucosa, PAF gradually increased and reached the maximum of 0.36 x 10(-8) M at 20 min, and thereafter quickly decreased to a non-detectable level.