High-salt diets during pregnancy affected fetal and offspring renal renin–angiotensin system

Abstract

Intrauterine environments are related to fetal renal development and postnatal health. Influence of salty diets during pregnancy on renal functions and renin–angiotensin system (RAS) was determined in the ovine fetuses and offspring. Pregnant ewes were fed high-salt diet (HSD) or normal-salt diet (NSD) for 2 months during middle-to-late gestation. Fetal renal functions, plasma hormones, and mRNA and protein expressions of the key elements of renal RAS were measured in the fetuses and offspring. Fetal renal excretion of sodium was increased while urine volume decreased in the HSD group. Fetal blood urea nitrogen was increased, while kidney weight:body weight ratio decreased in the HSD group. The altered ratio was also observed in the offspring aged 15 and 90 days. Maternal and fetal plasma antidiuretic hormone was elevated without changes in plasma renin activity and Ang I levels, while plasma Ang II was decreased. The key elements of local renal RAS, including angiotensinogen, angiotensin converting enzyme (ACE), ACE2, AT1, and AT2 receptor expression in both mRNA and protein, except renin, were altered following maternal high salt intake. The results suggest that high intake of salt during pregnancy affected fetal renal development associated with an altered expression of the renal key elements of RAS, some alterations of fetal origins remained after birth as possible risks in developing renal or cardiovascular diseases.

Vascular Response to Graded Angiotensin II Infusion in Offspring Subjected to High-Salt Drinking Water during Pregnancy: The Effect of Blood Pressure, Heart Rate, Urine Output, Endothelial Permeability, and Gender

“…Accordingly, there is a possibility that high-salt diets in pregnant rats may alter the AT1R expression in male offspring but not in female. Urine volume response to AngII was also increased in male offspring from mothers who received high-salt diet, while urine volume generally decreased in these offspring [28]. The results obtained for the kidney weight in the current study were inconsistence with the results reported in other experiments [28].…”

“…Urine volume response to AngII was also increased in male offspring from mothers who received high-salt diet, while urine volume generally decreased in these offspring [28]. The results obtained for the kidney weight in the current study were inconsistence with the results reported in other experiments [28]. Finally, significant difference was observed in serum nitrite level of mothers with salt and tap water 30 days after delivery, but no difference was observed between offspring (adults).…”

Alteration in the expression of the renin-angiotensin system in the myocardium of mice conceived by in vitro fertilization†

“…In addition to in vitro ART, a sub-optimal uterine environment following embryo transfer is thought to further influence the long-term viability of offspring. Interestingly, factors that create an adverse interuterine environment, including maternal high-salt diet, inflammation, and dietary restriction, have also been shown to alter the fetal and offspring RAS [57][58][59][60].…”

A maternal high salt diet disturbs cardiac and vascular function of offspring

“…hypernatremia) may contribute to the maternal effects of a high salt diet on offspring and, indeed, a maternal salt diet has been reported to increase plasma Na + levels of the mother and of both fetal and grown rat offspring [13]. However, no change in plasma Na + has also been reported in rats [25] and in sheep [29]. Furthermore, sodium concentrations in the amniotic fluid and mothers milk have been reported to be higher in dam fed a salt-supplemented diet, but that in the fetal/neonatal plasma was normal, perhaps due to increased urinary excretion of sodium [15].…”