Vascular effects of captopril in the prevention of genetic hypertension in the spontaneously hypertensive rat

Captopril (100 mg/kg, q.d., orally, from the 6th week of age) strongly inhibits genetic hypertension development (GHD) and this effect persists up to 12 weeks after treatment discontinuation. However, during these 12 weeks, systolic blood pressure and heart weight/body weight ratio (HW/BW) show a similar trend to slowly increase. We have investigated whether identical phenomena develop at the vascular level. Captopril strongly increased vascular mesenteric compliance, reduced aortic wall weight, mesenteric arterial wall lumen ratio and active contractile ability during treatment period and these effects were still observed up to 7 weeks after treatment interruption although there was a slight but progressive reduction in their intensity. Thus captopril opposes the structural and functional vascular and cardiac alterations which accompany GHD and this effect contributes to a large extent to the long-lasting preventive effects of the drug against GHD.