[Effects of chronic inhibition of converting enzymes on the structure and function of the large arterial trunks in rats]. / Effets de l'inhibition chronique de l'enzyme de conversion sur la structure et la fonction des gros troncs artériels chez le rat.

ABSTRACT

The effects of renovascular hypertension and of its treatment with perindopril, a converting enzyme inhibitor, on the structure and function of large arteries were studied on 2 kidneys, 1 clip Goldblatt rats. One month after surgery, the animals rendered hypertensive (n = 24) and those who had had a blank operation (n = 24) were divided into two groups receiving either perindopril 1 mg/kg/day or distilled water during 4 week At the end of treatment haemodynamic values, including arterial pressure and instant blood flow at Doppler velocimetry, were measured in anaesthesized rats. The mechanical properties of the carotid artery were studied by in situ measurement of carotid compliance in response to imposed pressures. Finally, morphometric parameters of the thoracic aorta, including thickness of the media, density of elastin, collagen and nuclei and nuclear surface area, were studied by means of an automatized image analysis system. Hypertension was associated with a characteristic increase in aortic impedance (14,479 +/- 5,171 vs 9,022 +/- 4,071 dyn.sec/cm5; p less than 0.01) and a decrease in systemic arterial compliance (2.41 +/- 0.96 vs 3.92 +/- 1.15 x 10-3 ml/mmHg; p less than 0.05) and carotid compliance (6.31 +/- 1.85 vs 3.8 +/- 3.4 X 10-2 mm3/mmHg; p less than 0.05). Treatment with perindopril normalized the systolic and diastolic pressures and completely reversed the artery rigidity markers. Our morphometric analysis of the aortic wall enabled us to relate these functional changes to structural changes in vascular wall.(ABSTRACT TRUNCATED AT 250 WORDS)