title: Elasto-thixotropic properties of bronchial mucus and polymer analogs. I. Experimental results.
abstract: The non-newtonian viscous and elasto-thixotropic properties of native and lyophilized pathological bronchial mucus and of polymer solutions (3% and 6% PIB in decalin) used as mucus analogs were analyzed using a cone-plate Carri-Med rheometer and a Couette viscoelastometer that we have specifically developed for measuring the rheological properties of bronchial mucus in clinical practice. The master curves obtained for apparent viscosity under steady conditions as a function of shear rates (gamma: 2.6 X 10(-3) to 6.9 X 10(1) sec-1) were fairly similar, whatever the apparatus used. Under transient conditions, at low shear rate (gamma less than 1.4 sec-1), PIB and mucus exhibited a typical viscoelastic behavior: the shear stress increased slightly up to a steady-state value. At higher gamma, a transitory overshoot of sigma characteristic of the elastothixotropic systems appeared. Such a behavior can be interpreted as resulting from structural changes such as formation and rupture of the three-dimensional network present in bronchial mucus as in polymer solutions.
mesh_terms: D001980:Bronchi / Q000378:metabolism*; D001991:Bronchitis / Q000503:physiopathology; D002923:Cilia / Q000648:ultrastructure; D004548:Elasticity; D006801:Humans; D008855:Microscopy, Electron, Scanning; D009093:Mucus / Q000502:physiology*; D011090:Polyenes; D011108:Polymers; D014783:Viscosity
chemical_list: D011090:Polyenes; D011108:Polymers; C008967:polyisobutylene