BLOOD PRESSURE, SODIUM BALANCE, AND MOLECULAR EXPRESSION OF RENAL SODIUM TRANSPORTERS IN MALE AND FEMALE MICE CONSUMING A HIGH SALT DIET: ARE FEMALES PROTECTED?

Sex Differences in Blood Pressure and Renal Sodium Transport

Authors

  • Alexander Rouch Oklahoma State University Center for Health Sciences College of Osteopathic Medicine (OSU-COM)
  • Avery Dutcher
  • Nicole Cueli
  • Andriana Pena
  • Liming Fan

Abstract

Background: The association between elevated dietary salt consumption and hypertension is well known.  Sex differences in blood pressure are also well known.  The purpose of this study was to determine sex differences in blood pressure and in the renal handling of sodium in mice consuming a high salt diet. 

Methods: Intact, 4 wk-old male and female mice (n=6/group) were placed in metabolic cages for 36 days.  Mice consumed a normal diet for the first 3 days followed by a 4%-salt diet for 30 days and finished with 3 days back on the normal diet.  Urinary Na+ excretion was determined daily. Sodium intake was determined from daily food intake.  Systolic blood pressure was measured daily via the tail-cuff method.  PCR was used to measure expression of renal sodium transporters. 

Results:  Female mice had lower SBP compared to male mice during high salt consumption (p < 0.001).  Sodium balance during the high salt consumption period was significantly higher for females (p < 0.005).   Molecular expression of the key sodium transporters was significantly higher in female kidneys.     

Conclusion:  Female mice had lower SBP compared to male mice while on a high salt diet yet they retained more sodium.  Higher expression of distal-nephron sodium transporters could potentially explain the higher sodium retention in females.  Results indicate female mice are protected from salt-induced increase in blood pressure.  We suspect that sex steroids have important roles in the renal handling of sodium and controlling blood pressure.

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Published

2022-05-16

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Section

Biomedical Sciences