[Female hormones in renal physiology. Salt sensitivity and regulation of epithelial proliferation]

Female sex hormones participate in the regulation of blood pressure and renal epithelial proliferation, effects not related to their reproductive function. About one-third of the world's population has abnormally high levels of blood pressure, hypertension, which is responsible for almost 50% of deaths from stroke and coronary heart disease. Salt sensitivity is a risk factor for cardiovascular morbidity and mortality and other diseases as well. We reported a model of salt sensitive hypertension in adult ovariectomized (oVx) Wistar rats. oVx rats are normotensive under normal salt intake (NS, 0.24% NaCl), but upon a high salt intake (HS, 1% NaCl) oVx rats developed a blood pressure profile of salt-sensitive hypertension. Our studies on kidney molecules related to sodium balance found that the circuit dopamine D1-like receptor, cytochrome P450 4A and Na+, K+-ATPase is altered by the absence of ovary hormones which is accompanied by a reduced ability to excrete sodium. In oVx rats HS intake also promotes changes in the expression of proteins related to sodium transport in peripheral blood mononuclear cells, mainly peripheral lymphocytes. Therefore, sodium transport is modified at several levels of normal physiology. Lately, we described that estradiol increases the rate of renal epithelial cell proliferation in primary cultures developed from human renal cortex. Thus, salt sensitivity, adaptive immunity, blood pressure and renal cell proliferation are complex biological responses regulated by female sex hormones.