Maternal low-protein diet suppresses vascular and renal endothelial nitric oxide synthase phosphorylation in rat offspring independent of a postnatal fructose diet

We investigated the effects of a postnatal fructose diet on the programmed hypertension and vascular and renal dysfunction in offspring from dams exposed to protein restriction. Pregnant Wistar rats were fed control and low-protein diets during the gestation and suckling periods. From the end of lactation, male offspring received standard chow or a 60% fructose diet: a control diet in the gestation and suckling periods and a control diet from the end of lactation, control-on-control (CC), 60% fructose diet-on-control (CF), control-on-low-protein diet (LPC) and 60% fructose diet-on-low-protein diet (LPF). The systolic blood pressure (SBP) was measured during treatment. At postnatal days 94-101, urinary 24 h nitrate/nitrite (NO(x)) content, protein levels of endothelial nitric oxide synthase (eNOS) and mRNA levels of endothelin-1 (ET-1), and NAD(P)H oxidase subunits in the aorta and kidney were examined. The SBP at postnatal days 97-101 increased in CF (137 +/- 2 mmHg, P < 0.05), LPC (135 +/- 1 mmHg, P < 0.05) and LPF (141 +/- 2 mmHg, P < 0.05), compared with CC (124 +/- 1 mmHg). The urinary NO(x) contents and eNOS phosphorylation in the aorta and kidney of CF, LPC and LPF decreased when compared with CC. In the aorta, the mRNA levels of NAD(P)H oxidase subunits p47phox in LPC and ET-1 in LPC and LPF increased. These results indicate that maternal protein restriction elevated the blood pressure, the downregulated nitric oxide production and eNOS phosphorylation, whereas the postnatal fructose diet made no significant difference to these alterations.