MORPHOLOGY AND MECHANICAL PROPERTIES OF THE SUBRENAL

properties Aims: This work focuses on the morphological and mechanical changes in the wall of the subrenal aorta in rats suff ering from arterial hypertension and chronic renal failure induced by subtotal nephrectomy (NX). Methods: The quantitative structural parameters were assessed using stereological methods. The mechanical properties were determined using uniaxial tensile tests. Results: Morphological results showed no signifi cant diff erences in the wall structure of NX rats ten days follow-ing the subtotal nephrectomy in comparison with the control animals. Pronounced structural changes appeared ten weeks after the nephrectomy. The area of the profi le of the arterial lumen, the volume fraction of elastin, and the elastin lamellar number in the tunica media were signifi cantly higher in the NX rats than in the control animals. The values of the volume fraction of the smooth muscle cells in the tunica media and the lamellar unit thickness were signifi cantly lower for the NX animals. Mechanical results showed that both kinds of tissues were characterized by a non-linear response when subjected to the tensile test. The moduli of elasticity of subrenal aortas in control and NX animals were diff erent only for large deformations: NX samples had higher stiff ness. The cyclic loading resulted in