Altered Renal α₂-Adrenoceptor Density in Dahl Rats Prenatally Exposed to a High Salt Diet

Abstract

Female inbred Dahl hypertension-sensitive (S/JR) and -resistant (R/JR) rats were maintained on an 8.0% or 0.4% NaCl-containing diet (w/w) during pregnancy. Their offspring were weaned to the same diets at 26 days of age and at 5 4 days of age the density of renal a–adrenoceptors was assessed using

³H-rauwolscine. In offspring prenatally exposed to the low salt diet, the density of adrenoceptors was greater In the S/JR rat than the R/JR rat, regardless of the postweaning diet or hypertension (HT) in S/JR rats weaned to a high salt diet. In contrast, the density of adrenoceptors was lower in S/JR but unchanged in R/JR offspring from dams that were maintained on a high salt diet during pregnancy. The rate at which HT developed in S/JR rats weaned to a high salt diet was similar, regardless of the dam's diet during pregnancy. This study indicates that prenatal exposure of the S/JR strain to a high salt diet can influence the development of renal a -adrenoceptors. Although the functional significance of these changes is unclear, it is reasonable to speculate that prenatal exposure to a hypertensinogenic stimulus such as a high salt diet may ultimately interfere with the functional development of the kidney.

Key Words:

• prenatal NaCl
• kidney
• adrenoceptors
• hypertension
• Dahl rat