Contraction to phenylephrine (PE), angiotensin II (ATII) and to endothelin-1 (ET-1) of abdominal (panels A, C and E) and thoracic (panels B, D and F) aortic rings from rabbits fed or not with a cholesterol diet for 2 or 8 weeks. Aortic rings were exposed to cumulative doses of the indicated agent. Values are presented as percentage of contraction relative to a KCl (80 mM) control contraction. Values are expressed as mean ± SEM (n = 16). *P < 0.05 vs Week 0.