title: High dietary salt does not significantly affect plasma 25-hydroxyvitamin D concentrations of Sprague Dawley rats.
abstract: BACKGROUND
  The Dahl salt-sensitive rat, but not the Dahl salt-resistant rat, develops hypertension and hypovitaminosis D when fed a high salt diet. Since the salt-sensitive rat and salt-resistant rat were bred from the Sprague Dawley rat, the aim of this research was to test the hypothesis that salt-resistant and Sprague Dawley rats would be similar in their vitamin D endocrine system response to high salt intake.
  
  
  RESULTS
  Sprague Dawley, salt-sensitive, and salt-resistant rats were fed high (80 g/kg, 8%) or low (3 g/kg, 3%) salt diets for three weeks. The blood pressure of Sprague Dawley rats increased from baseline to week 3 during both high and low salt intake and the mean blood pressure at week 3 of high salt intake was higher than that at week 3 of low salt intake (P < 0.05). Mean plasma 25-hydroxyvitamin D concentrations (marker of vitamin D status) of Sprague Dawley, salt-sensitive, and salt-resistant rats were similar at week 3 of low salt intake. Mean plasma 25-hydroxyvitamin D concentrations of Sprague Dawley and salt-resistant rats were unaffected by high salt intake, whereas the mean plasma 25-hydroxyvitamin D concentration of salt-sensitive rats at week 3 of high salt intake was only 20% of that at week 3 of low salt intake.
  
  
  CONCLUSIONS
  These data indicate that the effect of high salt intake on the vitamin D endocrine system of Sprague Dawley rats at week 3 was similar to that of salt-resistant rats. The salt-sensitive rat, thus, appears to be a more appropriate model than the Sprague Dawley rat for assessing possible effects of salt-sensitivity on vitamin D status of humans.
authors.affiliation: Department of Microbiology, Biochemistry, and Immunology, Morehouse School of Medicine, 720 Westview Dr, S,W,, Atlanta, Georgia 30310-1495, USA. mthierry-palmer@msm.edu.
authors.forename: Myrtle
authors.initials: M
authors.lastname: Thierry-Palmer
authors.forename: Teclemicael K
authors.initials: TK
authors.lastname: Tewolde
authors.forename: Neremiah L
authors.initials: NL
authors.lastname: Emmett
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Bayorh