Measurements of mouse pulmonary artery biomechanics.
BACKGROUND
Robust techniques for characterizing the biomechanical properties of mouse pulmonary arteries will permit exciting gene-level hypotheses regarding pulmonary vascular disease to be tested in genetically engineered animals. In this paper, we present the first measurements of the biomechanical properties of mouse pulmonary arteries.


METHODS
In an isolated vessel perfusion system, transmural pressure, internal diameter and wall thickness were measured during inflation and deflation of mouse pulmonary arteries over low (5-40 mmHg) and high (10-120 mmHg) pressure ranges representing physiological pressures in the pulmonary and systemic circulations, respectively.


RESULTS
During inflation, circumferential stress versus strain showed the nonlinear "J"-shape typical of arteries. Hudetz's incremental elastic modulus ranged from 27 +/- 13 kPa (n = 7) during low-pressure inflation to 2,700 +/- 1,700 kPa (n = 9) during high-pressure inflation. The low and high-pressure testing protocols yielded quantitatively indistinguishable stress-strain and modulus-strain results. Histology performed to assess the state of the tissue after mechanical testing showed intact medial and adventitial architecture with some loss of endothelium, suggesting that smooth muscle cell contractile strength could also be measured with these techniques.


CONCLUSIONS
The measurement techniques described demonstrate the feasibility of quantifying mouse pulmonary artery biomechanical properties. Stress-strain behavior and incremental modulus values are presented for normal, healthy arteries over a wide pressure range. These techniques will be useful for investigations into biomechanical abnormalities in pulmonary vascular disease.
Chesler
Naomi C
NC
Department of Biomedical Engineering, University of Wisconsin, 2146 Engineering Centers Building, 1550 Engineering Drive, Madison, WI 53706-1609, USA. Chesler@engr.wisc.edu
Thompson-Figueroa
John
J
Millburne
Ken
K
D000818:Animals; D001696:Biomechanical Phenomena / Q000379:methods; D001794:Blood Pressure; D046508:Culture Techniques / Q000295:instrumentation / Q000379:methods*; D004548:Elasticity; D005240:Feasibility Studies; D051379:Mice; D008810:Mice, Inbred C57BL; D011651:Pulmonary Artery / Q000166:cytology* / Q000502:physiology*; D013314:Stress, Mechanical