title: Effect of Fluid Viscosity on the Cilia-Generated Flow on a Mouse Tracheal Lumen.
abstract: Mucous flow in a tracheal lumen is generated by the beat motion of ciliated cells to provide a clearance function by discharging harmful dust particles and viruses. Due to its physiological importance, the cilia-generated flow and the rheological properties of mucus have been investigated intensively. The effects of viscosity on the cilia-generated flow, however, have not been fully clarified. In this study, we measured bulk background velocity of ciliary flow using a micro particle tracking velocimetry method under various viscosity conditions in mice. The results showed that the flow velocity decreased as the increase with viscosity of ambient fluid. Moreover, no previous study has clarified the pump power generated by cilia, which provides important information with regard to understanding the molecular motor properties of cilia. Measurements of both the ciliary flow and the ciliary motion were conducted to determine the cilia pump power. Our results indicated that the cilia pump during the effective stroke did not drive the ciliary flow efficiently under high viscosity conditions; these findings are necessary to resolve the clearance function.
authors.affiliation: Department of Finemechanics, Tohoku University, Sendai, Japan. kenji@pfsl.mech.tohoku.ac.jp.
authors.forename: Kenji
authors.identifier: 0000-0001-8187-6773
authors.initials: K
authors.lastname: Kikuchi
authors.affiliation: Graduate School of Biomedical Engineering, Tohoku University, Sendai, Japan.
authors.forename: Tomofumi
authors.initials: T
authors.lastname: Haga
authors.affiliation: Graduate School of Biomedical Engineering, Tohoku University, Sendai, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Numayama-Tsuruta
authors.affiliation: Department of Molecular Function and Life Science, Aichi University of Education, Kariya, Japan.
authors.forename: Hironori
authors.initials: H
authors.lastname: Ueno
authors.affiliation: Department of Finemechanics, Tohoku University, Sendai, Japan.|Graduate School of Biomedical Engineering, Tohoku University, Sendai, Japan.
authors.forename: Takuji
authors.initials: T
authors.lastname: Ishikawa
mesh_terms: D000818:Animals; D001693:Biological Transport, Active; D002923:Cilia / Q000502:physiology; D005260:Female; D051379:Mice; D008813:Mice, Inbred ICR; D008954:Models, Biological; D020545:Respiratory Mucosa / Q000502:physiology*; D014132:Trachea / Q000502:physiology*; D014783:Viscosity
keywords: Cilia; Cilia pump power; Fluid mechanics; Particle tracking velocimetry; Transport phenomena