Zinc increases ciliary beat frequency in a calcium-dependent manner.
BACKGROUND
Dynamic regulation of respiratory ciliary beat frequency (CBF) is regulated by fluxes in intracellular calcium (Ca(2+)). P2X receptors (P2XR) are extracellular ATP-gated, Ca(2+)-permeable, nonselective cation channels. Zinc increases intracellular Ca(2+) in a sodium (Na(+))-free environment through activation of P2XR channels. We hypothesize that topical zinc increases CBF in a Ca(2+)-dependent fashion as a result of this mechanism.


METHODS
The apical surface of mouse sinonasal air-liquid interface cultures were bathed in zinc in a Na(+)-free solution with or without Ca(2+). High-speed digital video imaging captured and analyzed CBF at a sampling rate of 100 frames/s.


RESULTS
CBF significantly increased fourfold over baseline from 5.99 +/- 3.16 Hz to 22.4 +/- 4.33 Hz in the presence of zinc chloride (50 micromoles) and calcium chloride (3 mM). This effect is abolished in the presence of extracellular Na(+) and was pH dependent.


CONCLUSIONS
Zinc stimulates CBF in the presence of Ca(2+) likely through activation of P2X receptors. Thus, zinc represents a promising agent for stimulation of mucociliary clearance.
Woodworth
Bradford A
BA
Otolaryngology, Department of Surgery, University of Alabama-Birmingham, Birmingham, Alabama, USA. bwoodwo@hotmail.com
Zhang
Shaoyan
S
Tamashiro
Edwin
E
Bhargave
Geeta
G
Palmer
James N
JN
Cohen
Noam A
NA
D000818:Animals; D020013:Calcium Signaling; D002478:Cells, Cultured; D002923:Cilia / Q000187:drug effects / Q000502:physiology*; D002925:Ciliary Motility Disorders / Q000188:drug therapy / Q000503:physiopathology; D004847:Epithelial Cells / Q000187:drug effects / Q000473:pathology / Q000502:physiology*; D006863:Hydrogen-Ion Concentration; D051379:Mice; D009079:Mucociliary Clearance / Q000187:drug effects; D009300:Nasal Septum / Q000473:pathology; D012815:Signal Processing, Computer-Assisted; D015032:Zinc / Q000494:pharmacology*
D015032:Zinc