Affiliations: [a] Groupe d’Etude des Systèms Muco-ciliaires, Laboratoire d’Histologie, Faculté de Médecine, 51095 Reims Cedex France | [b] Unité de Physiopathologie Respiratoire, U 14 INSERM, France | [c] Unité 284 INSERM, Instrumentation Avancée et Réactifs, 54511 Vandoeuvre-les-Nancy, France | [d] Institut Laue Langevin, 38000 Grenoble et LBHP, Université Paris 7, Paris, France
Note: [*] Present address: LBHP, Université Paris 7 - Paris.
Note: [] Accepted by: Guest Editor J.F. Stoltz
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 (γ˙: 2.6×101 to 6.9×10 sec−1) were fairly similar, whatever the apparatus used. Under transient conditions, at low shear rate (γ˙ < 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 γ˙, a transitory overshoot of σ 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.
