Eman Y. Gohar, Ph.D., MS Assistant Professor of Medicine, Division of Nephrology and Hypertension at Vanderbilt University Medical Center. In this video, she speaks about Acclimation to a High‐Salt Diet Is Sex Dependent.
Although premenopausal women are less likely than males to suffer hypertension and saltrelated problems, the role of sex on mechanisms regulating Na+ homeostasis during dietary salt challenges is unknown. We wanted to see if female rats have a better ability to acclimatize to higher dietary salt intake challenges.
Methodologies and outcomes:
Agematched male and female Sprague Dawley rats fed a normalsalt (NS) diet (0.49 percent NaCl) were given a fiveday highsalt diet (4.0 percent NaCl). During the NS and highsalt diet periods, we measured serum, urine, skin, and muscle electrolytes, total body water, and kidney Na+ transporters. During the 5-day highsalt challenge, females saw greater increases in natriuresis, but serum Na+ and body water concentrations increased solely in males. To see if females are better prepared to deal with fluctuations in dietary salt, we tested if the renal endothelin1 natriuretic system is more active in female rats than in males. Female rats excreted more urine endothelin1 than males throughout the NS diet. Furthermore, Ingenuity Pathway Analysis of RNA sequencing data revealed an enrichment of endothelin signaling pathway transcripts in the inner medulla of NSfed female rats' kidneys compared to male counterparts. Women showed a greater urine endothelin1 excretion rate than men in human subjects who ingested a Na+controlled diet (3314–3668 mg/day) for 3 days, which was consistent with our findings in NSfed rats.
These findings imply that female sex provides a stronger ability to maintain Na+ homeostasis following dietary Na+ challenge acclimation and that the intrarenal endothelin1 natriuretic pathway is strengthened in women.