Early, short-term treatment with captopril permanently attenuates cardiovascular changes in spontaneously hypertensive rats

The purpose of the current study was to determine if early, short-term treatment of spontaneously hypertensive rats (SHR) with captopril would cause a persistent attenuation of the structural alterations of the heart, aorta, and coronary arteries that are commonly seen in adult SHR. Therefore, mating pairs of SHR were treated with captopril and the pups were kept on captopril (SHRC) or were taken off captopril at two months (SHROC). Untreated SHR and Wistar-Kyoto (WKY) rats were mated and served as controls. At 8-10 months of age, heart weight and left ventricular weight / body weight ratios were increased in SHR compared to WKY, SHRC, and SHROC. Aortic medial areas of SHR and SHROC were similar and were larger than WKY and SHRC. Nuclear density in SHR and SHROC was less than WKY and SHRC suggesting hypertrophy of the medial wall. In coronary vessels, medial thickness was greatest in SHR, while there was no difference among WKY, SHRC, SHROC. These data suggest that early, short-term treatment of SHR with captopril permanently attenuated the structural alterations in the heart and coronary vessels that are commonly seen in adult SHR.