Female mice retain more sodium than male mice but maintain lower blood pressure during 30 days on a high salt diet (1135.1)

High salt consumption contributes to hypertension. The kidneys must excrete ingested sodium in order to maintain normal blood pressure. Our previous study showed that female mice had lower renal excretion of sodium (Nae) than male mice for a 15‐day period of high salt consumption. The goal of this study was to determine if sex differences in Nae and blood pressure (BP) occur from a 30‐day period of high salt consumption. Intact female and male 12‐week old mice (n=6/group) consumed a 4% salt diet in metabolic cages for 30 days. Nae was determined from daily measurements of urine sodium concentration and urine volume. Sodium intake (Nai) was determined from daily food intake. BP was measured via the tail‐cuff method. Real‐time quantitative PCR was used to measure expression of renal sodium transporters. For the 30‐day period, average daily Nae/Nai (%) was significantly lower in female mice compared to male mice (53.3±2.7 vs 68.1±1.8, respectively, p<0.0001) in addition to the mean BP (mmHg) (78.4 ±1.0 vs 84.9 ±1.2 respectively, <0.0005). Expression of the renal NKCC2 mRNA was over 5‐fold higher in the female kidney. We conclude that female mice retain more sodium and maintain lower BP during high salt consumption compared to male mice. This study indicates that female mice exposed to a high salt diet are protected from hypertension for a period of 30 days despite higher sodium retention. Grant Funding Source : Supported by OK INBRE 8P20GM103447 Summer Research Program