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[The inhibitory effects of platelet activating factor (PAF) on ciliary activity of human paranasal sinus mucosa]
T Ganbo1, K Hisamatsu, H Inoue
1Department of Otorhinolaryngology, Isawa Kyoutou Hospital.
Abstract:
The effect of platelet activating factor (PAF) on human paranasal ciliated cells was investigated in vitro. Normal human paranasal sinus mucosa was obtained by surgical procedure and incubated with Eagle's MEM containing 10% FCS in the form of tissue culture. Ciliary activity was viewed at 37 degrees C under an inverted microscope equipped with a thermoregulator and a humidified CO2 chamber, recorded on video tapes and photoelectrically measured. Ciliary inhibition was observed by the treatment with PAF, in a dose dependent manner, at concentrations from 10(-10) M to 10(-6) M. The inhibitory effect of 10(-8) M PAF on ciliary activity was completely blocked when the mucosa was treated with 10(-6) M CV-3988 or 10(-6) M CV-6209 (specific PAF receptor antagonists). By the radioimmunoassay, the concentration of PAF in tissue culture was reduced by half within 12.5 min, and within 60 min it was only 5% of the initial concentration. There was no significant difference in ciliary inhibition between irrigation after a 60 min incubation with 10(-8) M PAF and non-irrigation. These results indicate that PAF inhibited ciliary activity directly and specifically, and induced irreversible damage primarily within the first 60 min after the challenge.
Insights
Platelet activating factor (PAF) directly inhibits human paranasal ciliated cell activity in a dose-dependent manner. This effect is specific and causes irreversible damage within the first hour of exposure.
Area of Science:
- Otorhinolaryngology
- Immunology
- Cell Biology
Context:
- Human paranasal sinus mucosa is crucial for mucociliary clearance.
- Platelet-activating factor (PAF) is a potent inflammatory mediator.
- Ciliary function is vital for respiratory health.
Purpose:
- To investigate the in vitro effect of PAF on human paranasal ciliated cells.
- To determine the dose-dependent and specific nature of PAF-induced ciliary inhibition.
- To assess the time course and reversibility of PAF's impact on ciliary activity.
Summary:
- PAF was applied to human paranasal ciliated cells in tissue culture.
- Ciliary activity was measured and observed to be inhibited by PAF in a dose-dependent manner (10^-10 M to 10^-6 M).
- Specific PAF receptor antagonists (CV-3988, CV-6209) blocked PAF's inhibitory effect, confirming specificity. PAF concentration decreased significantly over 60 minutes, and damage appeared irreversible within this timeframe.
Impact:
- PAF directly and specifically inhibits human paranasal ciliated cell function.
- The findings suggest PAF plays a role in sinonasal inflammatory conditions affecting mucociliary clearance.
- Understanding PAF's mechanism provides insights into potential therapeutic targets for sinonasal diseases.