Pre- and Neonatal Exposure to a High Salt Diet and the Susceptibility to Hypertension in the Dahl Rat

Abstract

The effects of a low or high salt diet (0.4% or 8.0% NaCI w/w) on pregnant or lactating inbred Dahl hypertension-sensitive (S/JR) and hypertension-resistant (R/JR) rats were examined. Offspring from these groups were weaned to a high or low salt diet and their susceptibility to salt-induced hypertension (HT) was investigated. Pregnancy attenuated the development of salt-induced HT in S/JR dams and reduced blood pressure (BP) in R/JR dams. In the S/JR strain, HT during pregnancy had little effect on infant mortality but did suppress the growth rate. Pre-weaning RP was greater in the S/JR offspring of dams maintained on a high salt diet during pregnancy. At maturity, rats in this group displayed a significantly greater degree of cardiac hypertrophy than rats prenatally exposed to a low salt diet. S/JR pups of dams maintained on a high salt diet while nursing also displayed a greater than normal increase in BP during the pre-weaning period, Prenatal exposure of the S/JR strain to a high salt diet also facilitated the pathogenesis of salt-induced HT in rats weaned to a 2.0% NaCl-containing diet. Pre- or neonatal dietary manipulations had little effect on the R/JR strain. The results of this study demonstrate that maternal high salt intake or severe maternal HT has early effects on BP and facilitates the post-weaning development of salt-induced HT in S/JR offspring.

Key Words:

• prenatal
• neonatal
• NaCl
• hypertension
• Dahl rat