Fig. 4. Effect of 1 -H -[1,2,4]oxidazole[4,3-a]quinoxalin-1-one (ODQ, Ki = 0.3 μm) 22on propofol-induced enhancement of ciliary beat frequency (CBF). CBF was measured at baseline and 25 min after the addition of vehicle (0.1% dimethyl sulfoxide), propofol (100 μm), or various concentrations of ODQ (1–100 μm). Values are expressed as a percentage change from baseline CBF and represent the mean ± SD. There is a significant difference among the groups (P < 0.0001). *P < 0.05, significantly different from vehicle; †P < 0.05, significantly different from 100 μm ODQ; ‡P < 0.05, significantly different from 100 μm propofol; ¶P < 0.05, significantly different from 1 μm ODQ + 100 μm propofol; §P < 0.05, significantly different from 10 μm ODQ + 100 μm propofol.