Effects of fetal and neonatal renin-angiotensin system blockade in Lyon hypertensive rats

It has been shown that a brief period of angiotensin-converting enzyme (ACE) inhibition in growing spontaneously hypertensive rats (SHRs) induces long-term decrease of the blood pressure (BP) level. This study assessed whether persistent effects of ACE inhibition could be disclosed in Lyon genetically hypertensive (LH) rats treated from conception to age 3 weeks. ACE inhibition was obtained with captopril (100 mg/kg/24 h in the drinking water of the breeders) because this compound crosses the placental barrier. For each of the six treated pairs, the first litter was discarded, the second served as control, whereas the third and the fourth were obtained during captopril treatment. Six other pairs remained untreated. Aortic BP was beat-to-beat recorded in freely moving 14-week-old rats. It was observed that captopril reduced the number of newborns (42 in the second vs. 17 rats in the third litter of six LH pairs). BP and left ventricle weight did not differ between control and treated animals. It is concluded that, unlike SHRs, in LH rats, ACE inhibition is devoid of persistent effects on BP after cessation of the treatment.