Platelet activating factor induced respiratory mucosal damage.

Human sinus mucosal specimens from eight normal individuals were exposed to platelet activating factor (PAF) at concentrations ranging from 10(-6) M to 10(-11) M in a humidified CO2 chamber at 37 degrees C. The mucosal surface of the specimens was recorded on video tapes and magnified 2,500 times on a 19-inch television (TV) monitor. Ciliary activity of each ciliated cell was photoelectrically measured on the TV monitor in real time. PAF induced mucosal damage which resulted in a coarse profile including ciliostasis and exfoliation of epithelial cells. The length of the incubation period in which the initial coarse profile occurred on the mucosal surface inversely correlated with the concentration of exposed PAF ranging from 10(-6) M to 10(-10) M with r = -0.712 (p less than 2 x 10(-4)). Both the control medium and 10(-8) M lysoPAF showed no effect on ciliary activity or mucosal surface alteration even after 24 hr of exposure. Significant ciliary inhibition was noted after 6 hr of exposure to PAF at concentrations of 10(-8) M and 10(-10) M (p less than 0.05). After 10 hr of exposure, significant ciliary inhibition (p less than 0.01) was noted at all concentrations. Inhibition occurred in a time- and dose-dependent manner. The length of the incubation period in which initial ciliostatis occurred and the level of PAF concentration showed an inverse correlation with r = -0.918 (p less than 10(-6)). These results indicate that PAF is cytotoxic to human respiratory mucosa.