Effect of Postnatal High-Protein Diet on Kidney Function of Rats Exposed to Intrauterine Protein Restriction

Poor fetal growth is linked with long-term detrimental effects on health in late life. We have previously shown that maternal protein restriction leads to hypertension and a reduced number of glomeruli in adult offspring. The aim of this study was to investigate the influence of a postnatal high-protein (HP) diet on renal development and renal function in rats subjected to a low-protein (LP) diet in fetal life. Sprague-Dawley rats were fed an LP diet throughout pregnancy. Male pups were given either a normal-protein (NP) diet (LP/NP) or HP diet (LP/HP), and normal male pups as control (NP/NP). At 12 wk, LP/HP offspring displayed no increase in glomerular number but showed elevated blood pressure and proteinuria compared with the LP/NP group. There was minimal fusion of foot processes in LP/NP rats compared with a moderate fusion of foot processes and hyperplasia of mesangial cells in LP/HP rats. Renal desmin mRNA levels were elevated in both LP/NP and LP/HP groups but more significantly in the LP/HP group. This study suggests that postnatal HP diet amplifies the renal damage induced by fetal under-nutrition. Podocyte injury may be one of the mechanisms by which fetal protein restriction leads to proteinuria. (Pediatr Res 68: 100-104, 2010)