title: Shear viscosity of the surfactant from dog lungs.
abstract: Surface viscosity (eta S) was measured in the pulmonary lavage fluid obtained from 40 mongrel dogs. Two experimental methods were employed to determine surface viscosity: a) Fourt's "torsion pendulum" procedure; and b) the "viscous traction" viscosimeter. A satisfactory correlation (r = 0.88) between these two methods was obtained. The mean value for surface viscosity of the pulmonary lavage fluid was 3.8 X 10(-2) surface-poise (s.p.) with the torsion pendulum procedure, and 4.3 X 10(-2) s.p. with the viscous traction viscosimeter. The implications of surface viscosity in pulmonary mechanics is discussed, as well as the effects of blood plasma addition to the pulmonary lavage fluid. A significant increase of surface viscosity could be observed when blood plasma was added to the hypophase, in concentrations greater than 0.1%. This increase in surface viscosity might be of importance when related to the augmented respiratory work during the evolution of pulmonary edema.
mesh_terms: D000818:Animals; D001809:Blood Viscosity; D004285:Dogs; D010827:Physiology / Q000295:instrumentation; D011654:Pulmonary Edema / Q000503:physiopathology; D011663:Pulmonary Surfactants / Q000502:physiology*; D013314:Stress, Mechanical; D013499:Surface Properties; D014783:Viscosity
chemical_list: D011663:Pulmonary Surfactants