Sex Differences in Urinary Exosomes from Salt‐sensitive 129Sv Mice

129Sv mice are susceptible to the development of salt‐induced hypertension and renal damage. We and others observed that female 129Sv mice have lower systolic blood pressure compared to male 129Sv mice. We did not find differences in electrolyte excretion or osmolality between female and male 129Sv mice. Urinary exosomes originate from different cell types such as renal epithelial cells. Their cargo is a source of biomarkers in the pathogenesis of hypertension and renal disease. We recently showed kidney exosomes may play a role for intercellular communication in the nephron. We hypothesized that there are differences in the production of exosomes and their cargo from female and male salt‐sensitive 129Sv mice. Exosomes were characterized by size using NanoSight Analysis and by Western blotting for the exosomal markers flotillin‐1, annexin V, and Hsp70. Using nanoparticle tracking analysis, we found a greater concentration of urinary exosomes from salt‐loaded female 129Sv mice compared to age‐matched salt‐loaded male 129Sv mice. On a normal‐salt diet, the size of the urinary exosomes from the female mice was smaller compared to the male mice, but the opposite was noted when a high‐salt diet was maintained. Importantly, we found urinary exosomes from salt‐loaded female 129Sv mice are enriched in annexins compared to males. Future studies will be performed to determine if the enrichment of annexins in the kidney of female mice contributes to the up‐regulation of urinary exosomes and altered exosomal cargo. Support or Funding Information This research was supported by a National Institutes of Health grant K01 DK099617 (to A. A. Alli). This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .