Fetal development and renal function in adult rats prenatally subjected to sodium overload

Abstract

The aims of this study were (1) to evaluate two factors that affect fetal development--placental oxidative stress (Ox) and plasma volume (PV)--in dams with sodium overload and (2) to correlate possible alterations in these factors with subsequent modifications in the renal function of adult offspring. Wistar dams were maintained on 0.17 M NaCl instead of water from 20 days before mating until either the twentieth pregnancy day/parturition or weaning. Colorimetric methods were used to measure Ox in maternal and offspring tissues, PV, 24-h urinary protein (U(Prot24 h)) and serum triacylglycerols (TG) and cholesterol (Chol). Renal hemodynamics was evaluated in the offspring at 90 days of age using a blood pressure transducer, a flow probe and inulin clearance to measure mean arterial pressure (MAP), renal blood flow and glomerular filtration rate (GFR), respectively. The number of nephrons (NN) was counted in kidney suspensions. Dams showed unchanged PV, placental Ox and fetal weight but increased U(Prot24 h) (150%, P < 0.05). Prenatally sodium-overloaded pups showed increased U(Prot24 h) (45%, P < 0.05) but unchanged MAP, renal hemodynamics, NN and kidney Ox. Prenatally and postnatally sodium-overloaded rats showed increased U(Prot24 h) (27%, P < 0.05) and kidney Ox (44%, P < 0.05), reduced GFR (12%, P < 0.05), increased PV (26%, P < 0.05) and unchanged MAP and NN. The TG increased in both groups of treated offspring (21%, P < 0.05), whereas Chol increased only in the postnatally sodium-overloaded group. We conclude that salt overload from the prenatal stage until weaning leads to alterations in lipid metabolism and in the renal function of the pups, which are additional to those alterations seen in rats only overloaded prenatally.

Both high and low maternal salt intake in pregnancy alter kidney development in the offspring

“…The final number of glomeruli in offspring of Sprague-Dawley dams on IS is in agreement with data reported by others (5,30). In contrast to our results, Cardoso et al (13) did not observe lower nephron number in offspring of dams with increased sodium intake in pregnancy. The discrepancy may be explained by a different sodium exposition, different rat strain, but also by a less-exact method to determine nephron number in the study of Cardoso et al Interestingly, the increased albuminuria in those offspring was present in both studies.…”

How the Kidney Is Impacted by the Perinatal Maternal Environment to Develop Hypertension1

“…Oxidative stress is increased in the kidneys of prenatal undernourished rats [106,108,[116][117][118] as well as in the offspring of mothers submitted to placental insufficiency [119] and sodium overloads [120,121]. Hypertension in male offspring of mothers submitted to placental insufficiency is abolished by treatment with tempol, a mimetic of superoxide dismutase [118], indicating a key role for oxidative stress in the etiology of programmed hypertension.…”

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

“…Higher blood pressure was observed in offspring from mothers subjected to high-sodium intake during pregnancy and lactation [7, 10, 14, 15]. Also, prenatally sodium-overloaded pups showed disturbances in renal development, which leads to functional and structural alterations that persist in adult life [15].…”