Computer-assisted video measurement of inhibition of ciliary beat frequency of human nasal epithelium in vitro by xylometazoline.
The effect of xylometazoline, an alpha-adrenergic agonist, on ciliary beat frequency (CBF) was tested on samples of human nasal epithelium in vitro. Ciliated tissue was obtained from the inferior nasal turbinates of five normal individuals. CBF was measured from video recordings of ciliary activity using a computer-assisted photometric technique. The mean CBF of cells from the five subjects, followed for 40 min without xylometazoline, was 12.0 +/- 1.1 Hz. All concentrations of xylometazoline significantly decreased ciliary beat frequency. After a 10-min exposure, the mean CBF dropped to 3.8 +/- 0.4 with 0.1% xylometazoline, 4.9 +/- 1.0 with 0.05%, and 8.1 +/- 0.9 with 0.025%. Washing with control culture medium at least partially reversed the inhibition within 10 min. Phentolamine (10(-3) M), an alpha-adrenergic antagonist, did not alter CBF significantly when used alone, but partially blocked the strong cilioinhibitory effect of xylometazoline. This action of xylometazoline is similar to that of several commercially prepared decongestants that contain potentially ciliotoxic preservatives in addition to alpha-adrenergic agonists and supports the view that alpha-adrenergic agonists act directly on ciliated cells to inhibit ciliary activity.
Department of Biology, University of North Carolina, Greensboro 27412.
L N
LN
Curtis
J L
JL
Carson
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000328:Adult; D000368:Aged; D002923:Cilia / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D001330:Electronic Data Processing; D004848:Epithelium / Q000187:drug effects; D005260:Female; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D009079:Mucociliary Clearance / Q000187:drug effects* / Q000502:physiology; D009297:Nasal Mucosa / Q000187:drug effects*; D014741:Video Recording
D000316:Adrenergic alpha-Agonists; D007093:Imidazoles; C009695:xylometazoline