Effect of glycosaminoglycan degradation.
Jamal, Rehab Al, Peter J. Roughley, and Mara S. Ludwig.
1Meakins Christie Laboratories, Royal Victoria Hospital and 2Genetics Unit,
Shriner's Hospital for Crippled Children, McGill University, Montreal, Quebec, Canada
H2X 2P2
APStracts 7:0246L, 2000.
We tested the hypothesis that matrix glycosaminoglycans contribute to lung tissue
viscoelasticity. We exposed lung parenchymal strips to specific degradative enzymes
(chondroitinase ABC, heparitinase I, and hyaluronidase) and determined whether the
mechanical properties of the tissue were affected. Subpleural parenchymal strips were
obtained from Sprague-Dawley rats and suspended in a Krebs-filled organ bath. One end
of the strip was attached to a force transducer and the other to a servo-controlled lever
arm that effected sinusoidal oscillations. Recordings of tension and length at different
amplitudes and frequencies of oscillation were recorded before and after enzyme
exposure. Resistance, dynamic elastance, and hysteresivity were estimated by fitting the
equation of motion to changes in tension and length. Quasi-static stress-strain curves
were also obtained. Exposure to chondroitinase and heparitinase I caused significant
increases in hysteresivity, no decrement in resistance, and similar decreases in dynamic
elastance relative to control strips exposed to Krebs solution only. Conversely, measures
of static elastance were different in treated versus control strips. Hyaluronidase treatment
did not alter any of the mechanical measures. These data demonstrate that digestion of
chondroitin sulfate and heparan sulfate alters the mechanical behavior of lung
parenchymal tissues.
Received 23 September 1999; accepted in final form 9 August 2000
APS Manuscript Number L312-9.
Article publication pending Am J Physiol Lung Cell Mol Physiol
ISSN 1080-4757 Copyright 2000 The American Physiological Society.
Published in APStracts on 7 November 2000