Salt-induced hypertension in normotensive spontaneously hypertensive rats.

Abstract
Lifetime treatment with oral captopril prevents the development of hypertension in spontaneously hypertensive rats (SHR). We tested the hypothesis that this treatment also prevents the hypertensive response that occurs when untreated NaCl-sensitive SHR are placed on a high NaCl diet. Female SHR were continuously treated with oral captopril before conception and throughout lactation, and the offspring were similarly treated with oral captopril throughout life. At 6 weeks of age, treated male SHR were placed on an 8% (or remained on a 1%) NaCl diet, and systolic arterial pressure, heart rate, and body weight were monitored for 2 weeks. The 8% NaCl diet caused a rapid increase in arterial pressure in the lifetime captopril-treated rats, and 18 days after the initiation of the diet, the mean arterial pressure of this group was 136 +/- 7 mm Hg compared with 100 +/- 2 mm Hg in the 1% NaCl diet rats. The results of a second experiment confirmed the hypertensive effect of the high NaCl diet in lifetime captopril-...