AORTIC STIFFNESS AND LEFT-VENTRICULAR MASS IN A RAT MODEL OF ISOLATEDSYSTOLIC HYPERTENSION

We tested whether cardiac mass can be related to decreased aortic stif fness in an original rat model of isolated systolic hypertension. Incr eased aortic stiffness was produced by calcium overload of elastic art eries after vitamin D-3 plus nicotine treatment. Half of the animals w ere chronically treated with the angiotensin-converting enzyme inhibit or perindopril (1 mg/kg per day PO). Rats were pithed, and lower body vascular resistance was measured. Blood pressure was then increased by phenylephrine infusion. and carotidofemoral pulse wave velocity was m easured. This value together with those for thoracic aorta internal di ameter and medial thickness (determined after in situ fixation and his tomorphometry) were used to calculate elastic modulus. Vitamin D-3 plu s nicotine treatment produced parallel increases in cardiac mass and e lastic modulus, with a significant correlation between the two. There was no significant change in resistance. Treatment with perindopril re versed the changes in cardiac mass and elastic modulus but had no effe ct on resistance after calcium overload of the elastic arteries. In th is model of isolated systolic hypertension, we showed that cardiac mas s is related to arterial elasticity.