Proceedings of The Physiological Society
University of Manchester (2010) Proc Physiol Soc 19, PC247
Maternal food restriction during pregnancy impairs offspring renal function in the rat
S. M. Almeshari1, N. Ashton2, G. Badr1, I. M. Alhazza1, S. H. Alwasel1
1. Fetal Programming of Diseases Research Chair, King Saud University, Riyadh, Saudi Arabia. 2. Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom.
Maternal food restriction (MFR) during pregnancy programmes the development of hypertension in adult rat offspring (1). The kidneys of rats exposed to MFR develop fewer nephrons (2) suggesting that sodium retention may underlie the hypertension in this model. Accordingly, the aim of this study was to assess renal sodium handling by the MFR rat. Control pregnant Wistar rats had access to food ad libitum (C n = 7); the food restricted group received 50% of the food consumed by control rats from day 1 of pregnancy until birth (MFR n = 6). Offspring had free access to food. At 9 weeks systolic blood pressure (SBP) and renal function were assessed in male rats housed in metabolism cages. Creatinine clearance was calculated using the standard clearance formula (UCr * V/PCr). Plasma creatinine was determined from a blood sample taken at the end of the experiment under terminal chloroform anaesthesia. MFR offspring were significantly lighter at birth; however, by 9 weeks of age their body weights were comparable with those of controls (Table 1). SBP was higher in the MFR animals. Food and water intake did not differ between MFR and control rats. Creatinine clearance was significantly lower in MFR rats, but neither urine flow nor sodium excretion rates were different from controls. However, fractional excretion of sodium was greater in MFR rats. These data suggest that renal tubular handling of sodium in MFR rats is altered. MFR rats filter less sodium than controls, but excrete proportionately more of the sodium that is filtered. Net sodium retention may contribute to the elevated blood pressure of MFR rats.
Where applicable, experiments conform with Society ethical requirements