The rheological factor in mucociliary clearance.
The viscoelastic properties of sputum samples obtained from bronchitic patients were measured and correlated with the speed at which the samples were transported by the ciliary action of isolated pharyngeal palates of bull frogs maintained in amphibian Ringers solution at 28 degrees C. The viscoelastic properties were measured at very low shear stress which allowed to express them in terms of Newtonian viscosity and linear elastic modulus, which greatly minimized the variations in such measurements previously experienced with sputum. Samples with lower values of viscosity and moduli (less than 10,000 poises and 15 dynes per square centimeter, respectively) showed faster transport rates in a system where ciliary beat frequency and volume of added mucus were kept relatively constant.
D000818:Animals; D001991:Bronchitis / Q000503:physiopathology; D002923:Cilia / Q000503:physiopathology*; D004548:Elasticity; D006801:Humans; D008954:Models, Biological; D009092:Mucous Membrane / Q000503:physiopathology; D009093:Mucus / Q000502:physiology*; D010159:Palate / Q000503:physiopathology; D012212:Rheology; D013183:Sputum / Q000502:physiology; D014783:Viscosity