Fig. 6.

Aortic vascular smooth muscle cells (VSMC) were isolated from young and old male monkeys. The AFM force-indentation measurements are directly related to VSMC stiffness. All the individual data are plotted in (A), with white squares representing thoracic aorta and white circles for abdominal aorta. The data for young monkeys are on the left and old monkeys on the right. The horizontal lines show the average data for old monkeys and young monkeys. VSMC stiffness was greater in old vs. young monkeys, but these differences were not greater in abdominal, compared with thoracic aorta, as reflected by the almost complete overlap of data, indicating that this mechanism was not responsible for the greater increases in abdominal aortic stiffness in old monkeys. The average data are shown in (B), *p<0.05 by ANOVA.