Abstract
The aim of the present study is to investigate effect of aging on the rheological properties of the aortic wall in normal rabbits aged 10-12, 22-24 and 34-36 months old in relation to characteristics of the microstructure. The rheological properties were assessed with tension-strain, stress-strain and incremental elastic modulus at 50% stretching from the initial length. Circumferential wall strip 3.0 mm in width was prepared from the ascending, proximal thoracic and proximal abdominal aortas. Both ends of the strip were sandwiched between two especially-designed chucks attached to a tensile testing instruments, immersed in saline solution at 37°C and stretched at speed of 4.17 mm/min to generating tension at about 20 g. There were no significant changes in wall tension, wall stress, incremental elastic modulus and wall thickness among the three age groups. No remarkable alteration in the microstructure with aging was observed in these age groups. The rheological characteristics reflected histological findings in any of aortic region tested in these age groups. We can conclude that the rheological properties of the aorta in normal rabbits were not affected by aging within the age range from 10-12 to 34-36 months old.
