The lack of impact of peri-implantation or late gestation nutrient restriction on ovine fetal renal development and function

Abstract

Unbalanced nutrition during critical windows of development is implicated in determining the susceptibility to hypertension and cardiovascular disease in adult life, but the underlying mechanisms during fetal life have not been fully elucidated. We investigated the effects of moderate nutritional restriction during critical windows in gestation on late gestation fetal sheep growth, cardiovascular and renal renin-angiotensin system function. Ewes were fed 100% nutrient requirements (control), or 40–50% nutrient requirements during the peri-implantation period (1–31 days gestation (dGA), PI40 and PI50), or 50% nutrient requirements in late gestation (104–127 dGA). At 125 ± 2 dGA, fetal cardiovascular and renal function were measured at baseline, and during frusemide, angiotensin II (Ang II), phenylephrine and hypoxia challenges. Maternal undernutrition had no effect on fetal biometry, kidney weight, nephron number, basal cardiovascular function or cardiovascular and renal responses to frusemide. Fetal blood pressure response to Ang II was blunted in PI50 (P< 0.05), but not in PI40 groups. There was no difference between groups in the cardiovascular or endocrine response to hypoxia. The lack of effect of moderate undernutrition within key developmental windows of fetal kidney development on fetal renal structure and function suggests that renal mechanisms do not underlie our previous observations of cardiovascular dysfunction in adulthood following early-life undernutrition.