Present study tried to evaluate the influence of different diets (low- and high-salt, bicarbonate) administered during prenatal period on body and organ weights of newborn Dahl salt-sensitive (DS) and salt-resistant (DR) rats. Blood pressure of DR dams was not influenced by dietary loading but it was significantly increased by high-salt diet in DS rats. Blood pressure of all DS dams was higher when compared to the respective DR rats. There were significant negative correlations between mean arterial pressure of DS (but not DR) dams and body weight of newborns in all dietary groups. Litter sizes were comparable in all groups studied. High-salt diet increased body weight and relative heart weight of newborns of both genotypes. On the other hand, the influence of bicarbonate diet on body weight was more pronounced in DS pups whereas the effect on relative heart weight was seen only in DR newborns. The relative heart and kidney weights were significantly higher and relative liver weight significantly lower in newborns of DR dams when compared to those of DS dams irrespective of mother's diet. There was a tendency in all organs of DS newborns to contain less water in comparison with respective DR pups. It should be noted that in newborns of both genotypes bicarbonate diet lowered relative DNA content more than relative protein content. In conclusion, high-salt and bicarbonate diets exert dissimilar effects on prenatal body and organ development in Dahl rats.

Institute of Physiology Czechoslovak Academy of Sciences Prague