Effect of a chronic high-salt diet on whole-body and organ sodium contents of Dahl rats.
OBJECTIVE
To evaluate whether a high-salt diet causes retention of Na in Dahl rats.


METHODS
To compare the whole-body and organ (liver, spleen, kidney, heart, lung, femur, submaxillary gland and muscle) Na contents in Dahl salt-sensitive rats and Dahl salt-resistant rats.


METHODS
Rats aged 6-10 weeks of both strains were fed a normal-salt (0.4% NaCl) or a high-salt (8% NaCl) diet. The whole-body and organs were then ashed and their respective Na contents determined.


RESULTS
Salt-resistant rats fed the normal-salt diet had a higher whole-body Na content than did salt-sensitive rats. The high-salt diet increased the whole-body Na content of salt-sensitive rats significantly, but it did not increase that of salt-resistant rats. The high-salt diet caused a significant increase in the organ weight: body weight ratio for all organs of the salt-sensitive rats, except the submaxillary gland, but had no effect on the ratios for salt-resistant rats, apart from that for the kidney. The kidney, submaxillary gland and muscle Na concentrations were greater in salt-sensitive rats than they were in salt-resistant rats. Nonetheless, regardless of strain, the high-salt diet had no effect on organ and plasma Na concentrations. The high-salt diet increased the organ weights (liver, spleen, kidney, heart and lung) and the organ Na contents per kg body weight significantly for salt-sensitive rats but not for salt-resistant rats.


CONCLUSIONS
A high-salt diet caused Na retention in salt-sensitive rats only and this was partially due to enlargement of the organs.
Tsunooka
K
K
Department of Physiology, Gifu University, School of Medicine, Japan.
Morita
H
H
D000818:Animals; D001835:Body Weight; D051381:Rats; D012964:Sodium / Q000493:pharmacokinetics*; D012982:Sodium, Dietary / Q000494:pharmacology*; D014018:Tissue Distribution
D012982:Sodium, Dietary; D012964:Sodium