Effects of Perinatal Protein-Nacl Diets on Offspring's Blood Pressure andRenal Function in Lewis Rats

Abstract

Perinatal diets may affect the cardiovascular-renal functions of offspring. To understand effects of maternal diet on the renal function and blood pressure (BP) of offspring, protein (10% low, LP; 23% normal, NP) and/or NaCl (4% high salt, HS; 0.6% normal, NS) diets were started at pre-pregnancy through pups' weaning to either a 4% high NaCl (hs) or 0.6% NaCl (ns) diet. Telemetered BP data was analyzed by methods of linear least square rhythmometry. Systolic BPs (circadian mean ±SE mm Hg) were: NPNSns, 131±2; NPNShs, 137±2; NPHSns, 137±0.2; NPHShs, 134±3; LPNSns, 138±1; LPNShs, 138±0.6; LPHSns, 135±2; LPHShs, 142±2. Offspring in NPNShs and NPHSns had significantly in- creased SBPs versus NPNSns (both P<0.05). Most LP-offspring had increased SBP (P<0.01 to <0.05) and lower body weight (BW) with smaller glomerular filtration rate changes (renal reserve, RR-GFR) following overnight acute high- protein loads: RR-GFRs (inulin, ml/min/g kidney) for groups stated above were, respectively: 0.935; 0.927; 0.537; -0.064; -0.229; 0.057; -0.515; -0.404. The kidney weight/BW ratio of offspring was higher on hs- than on ns-diets (all P<0.001). Rats on a low caloric diet had reduced sclerotic glomerular numbers compared to those on normal diets (11.2±1 vs. 15.7±2, P<0.001), though glomerular numbers were similar in both groups. In summary, perinatal LP-HS diets significantly affected the BW, BP, renal injuries and kidney function of offspring. RR was seriously reduced, especially among offspring in hs- and perinatal LP groups. The most interesting result was the glomerular maturation staging in the pups, which suggests delayed nephrogenesis by a maternal LP diet.