Table 1.
Maternal salt diet has a marked impact on renal function in the pregnant dam.
Figure 1.
Increased extracellular salt blunts in vitro kidney but not lung development.
A–J: representative images of paired (left and right) kidneys (n = 4–6 replicates for analysis) cultured for 2 days in media with varying osmolality, generated using NaCl, mannitol or urea, at concentrations indicated on y-axes. K: growth (fold-increase in normalised surface area) of cultured kidneys or lungs (L). Estimated marginal means for data are presented after analysis by repeated measures general linear models with treatment (NaCl, mannitol or urea) and concentration (0, 25, 50, 100 mM) or specific interactions as fixed effects and time as a repeated measure (Genstat v14). The overall standard error of the difference (s.e.d.) between means for the statistical comparison is presented.
Table 2.
Maternal salt diet has little effect on feto-placental tissues in late gestation.
Figure 2.
Salt-exposed offspring have increased blood pressure throughout the circadian cycle.
For blood pressure, assessed by telemetry, data are from Control diet; n = 6 dams, n = 6/6 [male/female] offspring or high-salt (4% salt) diet; n = 6 dams, n = 5/5 [male/female] offspring. Values are either hourly means (A,B; derived from summary measures of 48 h recording) or the fitted model from non-linear regression [Fourier] analysis of all datapoints recorded over the 48 h period (C,D) and the respective output of circadian parameters from the model (E). Data are predicted means (±S.E.M.) and were analysed by mixed effect models with treatment (control vs. 4% salt) and sex (male vs. female) or their interaction as fixed and dam as a random effect (Genstat v14). NS, not significant.
Figure 3.
Salt-exposed offspring do not retain excess salt but have greater sodium excretion under low, but not high, salt-loading.
Na+ excretion were measured in 12 week old male and female offspring from dams fed control diet (Control, n = 12 dams; n = 9–12 males/females) or 4% salt diet with water ad libitum (4% Salt, n = 10 dams; n = 7–10 males/females). Paired plasma and urine were collected after 24 h in a metabolic crate after 5-days feeding either a low (0.26%; standard chow or LOW-SALT) or high-salt (4%; TD.08162, SALT-LOADED) diet. Data are means (±95% CI) and were analysed by mixed effect models with treatment (control vs. 4% salt) and sex (male vs. female) or their interaction as fixed and dam as a random effect (Genstat v14). NS, not significant.
Table 3.
Offspring renal function is unaffected by maternal salt-exposure.
Table 4.
The kidneys of maternally salt-exposed offspring appear to handle sodium appropriately.
Table 5.
The kidneys of maternally salt-exposed offspring appear to handle sodium appropriately under conditions of salt-loading.
Figure 4.
Salt-exposed offspring have increased plasma corticosterone and proximal colon SLC9A3 which influences gastrointestinal electrolyte handling.
Data are presented with mean (±95% CI) indicated and are from the adult offspring of dams fed a Control (0.26% salt) diet; n = 8 dams, n = 5–7 male/female offspring or high-salt (4% salt) diet; n = 6 dams, n = 4–6 male/female offspring. Plasma corticosterone was measured by ELISA. Faecal collection and measurement of electrolytes (by ICP-MS) were as described in Methods. Data were analysed by mixed effects models with treatment (control vs. 4% salt) and sex (male vs. female) or their interaction as fixed and dam as a random effect (Genstat v14). Corticosterone was analysed as log10 transformed to normalise the error distribution and is shown as an antilog for clarity. NS, not significant. PC, proximal colon. DC, distal colon.