title: Variations in local elastic modulus along the length of the aorta as observed by use of a scanning haptic microscope (SHM).
abstract: Variations in microscopic elastic structures along the entire length of canine aorta were evaluated by use of a scanning haptic microscope (SHM). The total aorta from the aortic arch to the abdominal aorta was divided into 6 approximately equal segments. After embedding the aorta in agar, it was cut into horizontal circumferential segments to obtain disk-like agar portions containing ring-like samples of aorta with flat surfaces (thickness, approximately 1 mm). The elastic modulus and topography of the samples under no-load conditions were simultaneously measured along the entire thickness of the wall by SHM by using a probe with a diameter of 5 μm and a spatial resolution of 2 μm at a rate of 0.3 s/point. The elastic modulus of the wall was the highest on the side of the luminal surface and decreased gradually toward the adventitial side. This tendency was similar to that of the change in the elastin fiber content. During the evaluation of the mid-portion of each tunica media segment, the highest elastic modulus (40.8 ± 3.5 kPa) was identified at the thoracic section of the aorta that had the highest density of elastic fibers. Under no-load conditions, portions of the aorta with high elastin density have a high elastic modulus.
authors.affiliation: Division of Medical Engineering and Materials, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishiro-dai, Suita, Osaka 565-8565, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Moriwaki
authors.forename: Tomonori
authors.initials: T
authors.lastname: Oie
authors.forename: Keiichi
authors.initials: K
authors.lastname: Takamizawa
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Murayama
authors.forename: Toru
authors.initials: T
authors.lastname: Fukuda
authors.forename: Sadao
authors.initials: S
authors.lastname: Omata
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kanda
authors.forename: Yasuhide
authors.initials: Y
authors.lastname: Nakayama
mesh_terms: D000818:Animals; D001011:Aorta / Q000502:physiology*; D004285:Dogs; D055119:Elastic Modulus; D005109:Extracellular Matrix / Q000502:physiology; D066298:In Vitro Techniques; D020527:Microscopy, Scanning Probe