Perinatal salt restriction: A new pathway to programming adiposity indices in adult female Wistar rats

Low birth weight has been associated with increased obesity in adulthood. It has been shown that dietary salt restriction during intrauterine life induces low birth weight and insulin resistance in adult Wistar rats. The present study had a two-fold objective: to evaluate the effects that low salt intake during pregnancy and lactation has on the amount and distribution of adipose tissue; and to determine whether the phenotypic changes in fat mass in this model are associated with alterations in the activity of the renin-angiotensin system. Maternal salt restriction was found to reduce birth weight in male and female offspring. In adulthood, the female offspring of dams fed the low-salt diet presented higher adiposity indices than those seen in the offspring of dams fed a normal-salt diet. This was attributed to the fact that adipose tissue mass (retroperitoneal but not gonadal, mesenteric or inguinal) was greater in those rats than in the offspring of dams fed a normal diet. The adult offspring of dams fed the low-salt diet, compared to those dams fed a normal-salt diet, presented the following: plasma leptin levels higher in males and lower in females; plasma renin activity higher in males but not in females; and no differences in body weight, mean arterial blood pressure or serum angiotensin-converting enzyme activity. Therefore, low salt intake during pregnancy might lead to the programming of obesity in adult female offspring. (c) 2009 Elsevier Inc. All rights reserved

Salt-Induced Cardiac Hypertrophy and Interstitial Fibrosis Are Due to a Blood Pressure-Independent Mechanism in Wistar Rats

High salt intake is a known cardiovascular risk factor and is associated with cardiac alterations. To better understand this effect, male Wistar rats were fed a normal (NSD: 1.3% NaCl), high 4 (HSD4: 4%), or high 8 (HSD8: 8%) salt diet from weaning until 18 wk of age. The HSD8 group was subdivided into HSD8, HSD8+HZ (15 mg.kg(-1).d(-1) hydralazine in the drinking water), and HSD8+LOS (20 mg.kg(-1).d(-1) losartan in the drinking water) groups. The cardiomyocyte diameter was greater in the HSD4 and HSD8 groups than in the HSD8+LOS and NSD groups. Interstitial fibrosis was greater in the HSD4 and HSD8 groups than in the HSD8+HZ and NSD groups. Hydralazine prevented high blood pressure (BP) and fibrosis, but not cardiomyocyte hypertrophy. Losartan prevented high BP and cardiomyocyte hypertrophy, but not fibrosis. Angiotensin II type 1 receptor (AT(1)) protein expression in both ventricles was greater in the HSD8 group than in the NSD group. Losartan, but not hydralazine, prevented this effect. Compared with the NSD group, the binding of an AT(1) conformation-specific antibody that recognizes the activated form of the receptor was lower in both ventricles in all other groups. Losartan further lowered the binding of the anti-AT(1) antibody in both ventricles compared with all other experimental groups. Angiotensin II was greater in both ventricles in all groups compared with the NSD group. Myocardial structural alterations in response to HSD are independent of the effect on BP. Salt-induced cardiomyocyte hypertrophy and interstitial fibrosis possibly are due to different mechanisms. Evidence from the present study suggests that salt-induced AT(1) receptor internalization is probably due to angiotensin II binding. J. Nutr. 140: 1742-1751, 2010.FAPESP Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (Sao Paulo State Research Foundation)[05/50053-7

Maternal high-sodium intake alters the responsiveness of the renin-angiotensin system in adult offspring

Aims: The goal of the current study was to evaluate the impact of maternal sodium intake during gestation on the systemic and renal renin-angiotensin-aldosterone-system (RAAS) of the adult offspring. Main methods: Female Wistar rats were fed high- (HSD-8.0% NaCl) or normal-sodium diets (NSD-1.3% NaCl) from 8 weeks of age until the delivery of their first litter. After birth, the offspring received NSD. Tail-cuff blood pressure (TcBP) was measured in the offspring between 6 and 12 weeks of age. At 12 weeks of age, the offspring were subjected to either one week of HSD or low sodium diet (LSD-0.1 6%NaCl) feeding to evaluate RAAS responsiveness or to acute saline overload to examine sodium excretory function. Plasma (PRA) and renal renin content (RRC), serum aldosterone (ALDO) levels, and renal cortical and medullary renin mRNA expression levels were evaluated at the end of the study. Key findings: TcBP was higher among dams fed HSD, but no TcBP differences were observed among the offspring. Male offspring, however, exhibited increased TcBP after one week of HSD feeding, and this effect was independent of maternal diet. Increased RAAS responsiveness to the HSD and LSD was also observed in male offspring. The baseline levels of PRA. ALDO, and cortical and medullary renin gene expression were lower but the RRC levels were higher among HSD-fed male offspring (HSDoff). Conversely, female HSDoff showed reduced sodium excretion 4 h after saline overload compared with female NSDoff. Significance: High maternal sodium intake is associated with gender-specific changes in RAAS responsiveness among adult offspring. (C) 2012 Elsevier Inc. All rights reserved.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [05/54776-3]Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES

Advanced Glycation End Products and Bone Metabolism in Patients with Chronic Kidney Disease

ABSTRACT Advanced glycation end products (AGEs) accumulation may be involved in the progression of CKD‐bone disorders. We sought to determine the relationship between AGEs measured in the blood, skin, and bone with histomorphometry parameters, bone protein, gene expression, and serum biomarkers of bone metabolism in patients with CKD stages 3 to 5D patients. Serum levels of AGEs were estimated by pentosidine, glycated hemoglobin (A1c), and N‐carboxymethyl lysine (CML). The accumulation of AGEs in the skin was estimated from skin autofluorescence (SAF). Bone AGEs accumulation and multiligand receptor for AGEs (RAGEs) expression were evaluated by immunohistochemistry; bone samples were used to evaluate protein and gene expression and histomorphometric analysis. Data are from 86 patients (age: 51 ± 13 years; 60 [70%] on dialysis). Median serum levels of pentosidine, CML, A1c, and SAF were 71.6 pmol/mL, 15.2 ng/mL, 5.4%, and 3.05 arbitrary units, respectively. AGEs covered 3.92% of trabecular bone and 5.42% of the cortical bone surface, whereas RAGEs were expressed in 0.7% and 0.83% of trabecular and cortical bone surfaces, respectively. AGEs accumulation in bone was inversely related to serum receptor activator of NF‐κB ligand/parathyroid hormone (PTH) ratio (R = −0.25; p = 0.03), and RAGE expression was negatively related to serum tartrate‐resistant acid phosphatase‐5b/PTH (R = −0.31; p = 0.01). Patients with higher AGEs accumulation presented decreased bone protein expression (sclerostin [1.96 (0.11–40.3) vs. 89.3 (2.88–401) ng/mg; p = 0.004]; Dickkopf‐related protein 1 [0.064 (0.03–0.46) vs. 1.36 (0.39–5.87) ng/mg; p = 0.0001]; FGF‐23 [1.07 (0.4–32.6) vs. 44.1 (6–162) ng/mg; p = 0.01]; and osteoprotegerin [0.16 (0.08–2.4) vs. 6.5 (1.1–23.7) ng/mg; p = 0.001]), upregulation of the p53 gene, and downregulation of Dickkopf‐1 gene expression. Patients with high serum A1c levels presented greater cortical porosity and Mlt and reduced osteoblast surface/bone surface, eroded surface/bone surface, osteoclast surface/bone surface, mineral apposition rate, and adjusted area. Cortical thickness was negatively correlated with serum A1c (R = −0.28; p = 0.02) and pentosidine levels (R = −0.27; p = 0.02). AGEs accumulation in the bone of CKD patients was related to decreased bone protein expression, gene expression changes, and increased skeletal resistance to PTH; A1c and pentosidine levels were related to decreased cortical thickness; and A1c levels were related to increased cortical porosity and Mlt. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research

Low-sodium diet induces atherogenesis regardless of lowering blood pressure in hypertensive hyperlipidemic mice.

This study investigated the influence of sodium restriction and antihypertensive drugs on atherogenesis utilizing hypertensive (H) low-density lipoprotein-receptor knockout mice treated or not with losartan (Los) or hydralazine (Hyd) and fed low-sodium (LS) or normal-sodium (NS) chow. Despite reducing the blood pressure (BP) of H-LS mice, the LS diet caused arterial lipid infiltration due to increased plasma total cholesterol (TC) and triglycerides (TG). Los and Hyd reduced the BP of H-LS mice, and Los effectively prevented arterial injury, likely by reducing plasma TG and nonesterified fatty acids. Aortic lipid infiltration was lower in Los-treated H-LS mice (H-LS+Los) than in normotensive (N)-LS and H-LS mice. Aortic angiotensin II type 1 (AT1) receptor content was greater in H-NS than H-LS mice and in H-LS+Hyd than H-LS+Los mice. Carboxymethyl-lysine (CML) and receptor for advanced glycation end products (RAGE) immunostaining was greater in H-LS than H-NS mice. CML and RAGE levels were lower in LS animals treated with antihypertensive drugs, and Hyd enhanced the AT1 receptor level. Hyd also increased the gene expression of F4/80 but not tumor necrosis factor-α, interleukin (IL)-1β, IL-6, IL-10, intercellular adhesion molecule-1 or cluster of differentiation 66. The novelty of the current study is that in a murine model of simultaneous hypertension and hyperlipidemia, the pleiotropic effect of chronic, severe sodium restriction elicited aortic damage even with reduced BP. These negative effects on the arterial wall were reduced by AT1 receptor antagonism, demonstrating the influence of angiotensin II in atherogenesis induced by a severely LS diet

Low-sodium diet induces atherogenesis regardless of lowering blood pressure in hypertensive hyperlipidemic mice - Fig 5

<p>Histomorphometric analysis of immunofluorescence-stained AT1 receptor (<b>A</b> segments I and II; <b>B</b> segments III and IV), and vascular injury quantified by a histomorphometric analysis of immunofluorescence-stained CML (<b>C</b> segments I and II; <b>D</b> segments III and IV) and RAGE (<b>E</b> segments I and II; <b>F</b> segments III and IV); data are represented as the mean percentage of the total positively stained area of the aortic arch cross-sections; n = 4 mice per group. ^a <i>P</i> < 0.05, hypertensive mice fed a normal-sodium diet (H-NS) <i>vs</i> hypertensive mice fed a low-sodium diet (H-LS), Mann Whitney test. ^b <i>P</i> < 0.05, Kruskal Wallis with Dunn’s post hoc test applied for comparisons among LS groups.</p

Representative examples of lipid infiltration visualized by oil red O staining of the intima and media layers of different aortic arch segments from animal groups consisting of hypertensive mice fed a normal-sodium diet (H-NS), normotensive mice fed a low-sodium diet (N-LS), hypertensive mice fed a low-sodium diet (H-LS), hypertensive mice fed a low-sodium diet and treated with losartan (H-LS+Los) and hypertensive mice fed a low-sodium diet and treated with hydralazine (H-LS+Hyd).

<p>Arrows indicate sites of aortic arch lipid infiltration. ADV = adventitia, MED = media, INT = intima (400×).</p

Gene expression (mRNA) of the AT1 receptor (<i>Agtr1</i>) and RAGE (<i>Ager</i>) in the mouse aortic arch.

<p>Data are expressed as relative mRNA units normalized to mouse β2M expression. Mann Whitney test was used for comparisons between hypertensive mice fed a normal-sodium (H-NS) diet and hypertensive mice fed a low-sodium (H-LS) diet. The Kruskal Wallis test with Dunn’s post hoc test was applied for comparisons among the LS groups; n ≥ 4 mice per group.</p

Univariate regression analysis of arterial lipid infiltration in N and H LDLR KO mice fed a NS or LS diet treated or not with an antihypertensive drug.

<p>Univariate regression analysis of arterial lipid infiltration in N and H LDLR KO mice fed a NS or LS diet treated or not with an antihypertensive drug.</p