Oxidative stress response to air particle pollution in a rat nutritional growth retardation model.

Air pollution consisting of gases and particulate matter-(PM) represents a health problem in cities worldwide. However, air pollution does not impact equally all individuals, as children appear to be more vulnerable subpopulations. Air pollution and malnutrition are two distinct factors that have been associated with oxidative damage. Therefore, the interaction between environmental exposure and nutritional status in populations at risk needs to be explored. The aim of this study was to examine oxidative metabolism in lung, heart and liver in malnourished young rats exposed to residual oil fly ash (ROFA). A Nutritional Growth Retardation (NGR) model was developed in weanling male rats placed on a 20% restricted balanced diet for 4 weeks. Then, NGR and control rats were intranasally instilled with either ROFA (1mg/kg BW) or phosphate buffered saline (PBS). Twenty-four hr post-exposure lung, heart and liver were excised, and serum collected. ROFA induced lung and liver inflammation in control and NGR animals as evidenced by lung polymorphonuclear neutrophil (PMN) recruitment and alveolar space reduction accompanied by liver lymphocyte and binucleated hepatocyte level increase. In lung and liver, antioxidant defense mechanisms reduced lipoperoxidation. In contrast, only in NGR animals did ROFA exposure alter heart oxidative metabolism leading to lipid peroxidation. Although histological and biochemical tissue alterations were detected, no marked changes in serum liver and heart systemic biomarkers were observed. In conclusion, NGR animals responded differently to PM exposure than controls suggesting that nutritional status plays a key role in responsiveness to ambient air contaminants.

Efficacy of phytosterols and fish-oil supplemented high-oleic-sunflower oil rich diets in hypercholesterolemic growing rats.

Phytosterols (P) and fish-oil (F) efficacy on high-oleic-sunflower oil (HOSO) diets were assessed in hypercholesterolemic growing rats. Controls (C) received a standard diet for 8 weeks; experimental rats were fed an atherogenic diet (AT) for 3 weeks, thereafter were divided into four groups fed for 5 weeks a monounsaturated fatty acid diet (MUFA) containing either: extra virgin olive oil (OO), HOSO or HOSO supplemented with P or F. The diets did not alter body weight or growth. HOSO-P and HOSO-F rats showed reduced total cholesterol (T-chol), non-high-density lipoprotein-cholesterol (non-HDL-chol) and triglycerides and increased HDL-chol levels, comparably to the OO rats. Total body fat (%) was similar among all rats; but HOSO-F showed the lowest intestinal, epididymal and perirenal fat. However, bone mineral content and density, and bone yield stress and modulus of elasticity were unchanged. Growing hypercholesterolemic rats fed HOSO with P or F improved serum lipids and fat distribution, but did not influence material bone quality.

Monounsaturated fatty acids-rich diets in hypercholesterolemic-growing rats.

The effects of replacing dietary saturated fat by different monounsaturated fatty acid (ω-9MUFA) sources on serum lipids, body fat and bone in growing hypercholesterolemic rats were studied. Rats received one of the six different diets: AIN-93G (control, C); extra virgin olive oil (OO) + C; high-oleic sunflower oil (HOSO) + C or atherogenic diet (AT) for 8 weeks; the remaining two groups received AT for 3 weeks and then, the saturated fat was replaced by an oil mixture of soybean oil added with OO or HOSO for 5 weeks. Rats consuming MUFA-rich diets showed the highest body fat, hepatic index and epididymal, intestinal and perirenal fat, and triglycerides. T-chol and non-HDL-chol were increased in HOSO rats but decreased in OO rats. Bone mineral content and density were higher in both OO and HOSO groups than in AT rats. This study casts caution to the generalization of the benefits of MUFA for the treatment of hypercholesterolemia.

Prevalence of dyslipidemia and metabolic syndrome risk factor in overweight and obese children.

OBJECTIVE: To study the prevalence of dyslipidemia and metabolic syndrome risk factors in overweight/ obese children and adolescents. METHODOLOGY: The study included 139 healthy white Argentinean children/adolescents (aged 8-14 years) who were overweight (n = 30) or obese (n = 109), based on BMI z score according to WHO, 2007. Children were referred to the Nutrition Clinic, San Martin University Hospital, Buenos Aires, Argentina for evaluation and treatment. Dyslipidemia was considered when one or more serum lipids (mg/dL) were out of range: total cholesterol ≥ 200, high-density lipoprotein (HDL-C) ≤ 40, triglycerides (TG) > 110, low-density lipoprotein (LDL-C) > 130 or non-HDL-C > 145 and fasting blood glucose (FBG) > 110. Additional metabolic syndrome risk factors included: increased waist circumference (WC, ≥ 90th percentile) and high blood pressure (> 90th percentile). A history of low birth weight (< 2.5 kg) and a family history of: dyslipidemia (FHDL), premature acute myocardial infarction (FHPAMI) and/or type 2 diabetes mellitus (FHT2DM) were also assessed. RESULTS: The prevalence of dyslipidemia among overweight and obese children was 50.4% and its pattern was: hypertriglyceridemia 31.9%, low HDL-C 29.7%, high non-HDL-C 15.8%, hypercholesterolemia 11.9%, and elevated LDL-C 10.7%. The dyslipidemia was more often detected among those with increased WC (55.4%), FHDL (51.1%), and FHT2DM (48%); prevalence was lower in those with FHPAMI (18.7%) and low birth weight (4.3%). Most children presented a variety of metabolic syndrome risk factors; only 25.8% did not have any such alterations identified. BMI z score showed a positive association with TG and negative with HDL-C. Overweight and obesity increased the odds ratios of metabolic syndrome risk factors, hypertriglyceridemia and low HDL-C. CONCLUSIONS: Overweight/obese children were prone to have dyslipidemia and metabolic syndrome. Excess body weight is an important harbinger of health that requires the assessment of multiple parameters to discern further health concerns that may be amenable to specific treatment.

Improved bone status by the beta-blocker propranolol in an animal model of nutritional growth retardation.

The aim of the present research was to study if the beta-blocker propranolol, which is known to increase bone mass, could reverse the adverse skeletal effects of mild chronic food restriction in weanling rats. Male Wistar rats were divided into four groups: control, control+propranolol (CP), nutritional growth retardation (NGR) and nutritional growth retardation+propranolol (NGRP). Control and CP rats were fed freely with the standard diet. NGR and NGRP rats received, for 4 weeks, 80 % of the amount of food consumed by the control and CP rats, respectively. Results were expressed as mean values and sem. Food restriction induced detrimental effects on body and femur weight and length (P < 0.05) and bone structural and geometrical properties (P < 0.001), confirming results previously shown in our laboratory. However, the beta-blocker overcame the deleterious effect of nutritional stress on load-bearing capacity, yielding load, bone stiffness, cross-sectional cortical bone area and second moment of inertia of the cross-section in relation to the horizontal axis without affecting anthropometric, histomorphometric and bone morphometric parameters. The results suggest that propranolol administration to mildly chronically undernourished rats markedly attenuates the impaired bone status in this animal model of growth retardation.

mRNA of cytokines in bone marrow and bone biomarkers in response to propranolol in a nutritional growth retardation model.

BACKGROUND: The aim of this study was to assess mRNA of IL-6, TNFα and IL-10 cytokines in bone marrow, possible mediators involved in altered bone remodeling with detrimental consequences on bone quality in NGR (Nutritional growth retardation) rats. METHODS: Weanling male Wistar rats were assigned either to control (C) or experimental group (NGR) (n=20 each). C and NGR groups were assigned to 2 groups according to receiving saline solution (SS) or propranolol hydrochloride (P): C, C+P (CP), NGR or NGR+P (NGRP). For 4 weeks, NGR and NGRP rats received 80% of the amount of food consumed by C and CP, respectively, the previous day, corrected by body weight. P (7 mg/kg/day) was injected ip 5 days/week, for 4 weeks in CP and NGRP rats. Body weight and length were recorded. After 4 weeks, blood was drawn. Femurs were dissected for RNA isolation from bone marrow and mRNA of cytokines assays. RESULTS: Food restriction induced a significant negative effect on body growth in NGR and NGRP rats (p<0.001). P had no effects on zoometric parameters (p>0.05). CTX-I increased in NGR rats vs. C (p<0.001), but diminished in NGRP (p<0.01). Serum osteocalcin, PTH, calcium and phosphate levels remained unchanged between groups (p>0.05). In NGR, bone marrow IL-6 mRNA and IL-10 mRNA levels were low as compared to other groups (p<0.05). In contrast, bone marrow TNF-α mRNA levels were significantly high (p<0.05). CONCLUSIONS: This study provides evidences that NGR outcomes in a bone marrow proinflammatory microenvironment leading to unbalanced bone remodeling by enhancement of bone resorption reverted by propranolol.

Dyslipidemia is not associated with cardiovascular disease risk in an animal model of mild chronic suboptimal nutrition.

Previous studies performed in an experimental model of nutritional growth retardation (NGR) have observed metabolic adaptation. We hypothesized that changes in lipid-lipoprotein profile, glucose, and insulin levels occur, whereas overall body growth is reduced.The aim of this study was to assess serum lipid-lipoprotein profile, hepatogram, insulinemia and glycemia, and CVD risk markers in rats fed a suboptimal diet. Weanling male rats were assigned either to control (C) or NGR group. In this 4-week study, C rats were fed ad libitum a standard diet, and NGR rats received 80% of the amount of food consumed by C. Zoometric parameters, body fat content, serum lipid-lipoprotein profile, hepatogram, insulinemia, and glycemia were determined, and the cardiovascular disease (CVD) risk markers homeostasis model assessment-insulin resistance and homeostasis model assessment and ß-cell function were calculated. Suboptimal food intake induced a significant decrease in body weight and length, which were accompanied by a reduction of 50% in body fat mass. Serum lipoproteins were significantly higher in NGR rats, with the exception of high-density lipoprotein cholesterol, which remained unchanged. Nutritional growth retardation rats had decreased triglycerides compared with C rats. No significant differences were detected in liver function parameters. The CVD risk markers homeostasis model assessment (HOMA)-insulin resistance and homeostasis model assessment and ß-cell function were significantly lower in NGR rats. Mild chronic suboptimal nutrition in weanling male rats led to growth retardation and changes in the lipid-lipoprotein profile, glucose, and insulin levels while preserving the integrity of liver function. These data suggest a metabolic adaptation during suboptimal food intake, which ensures substrates flux to tissues that require constant energy-in detriment to body growth. The CVD risk markers suggested that mild chronic food restriction of approximately 20% could provide protection against this degenerative disease.

Bone status in an animal model of chronic sub-optimal nutrition: a morphometric, densitometric and mechanical study.

In children, inappropriate eating habits can induce a disease known as nutritional dwarfing (ND). Due to the link between nutritional condition and bone growth, the effects induced by a 20 % reduction of food intake on bone competence were assessed in an animal model of ND. Bone status during catch-up growth was also analysed. Male Wistar rats were divided into control (C) and ND groups. C rats were fed ad libitum. ND received 80 % of the diet consumed by C for 4 weeks (T4); thereafter, they were fed ad libitum for 8 weeks. Results, expressed as mean (SEM) for ND v. C, were as follows. At T4, body weight (g) and length (cm) and femur weight (g) and length (mm) were 97.35 (SEM 5.89) v. 199.07 (SEM 9.24), 16.91 (SEM 0.41) v. 20.26 (SEM 0.31), 0.30 (SEM 0.01) v. 0.46 (SEM 0.01) and 23.09 (SEM 0.29) v. 26.98 (SEM 0.26), respectively (P<0.001); bone mineral content (g) and density (g/cm(2)) were 0.014 (SEM 0.002) v. 0.030 (SEM 0.002) and 0.061 (SEM 0.004) v. 0.080 (SEM 0.003), respectively (P<0.001); load-bearing capacity (N), yielding load (N) and elastic stiffness (N/mm) were 25.06 (SEM 1.24) v. 50.34 (SEM 2.94), 23.72 (SEM 1.02) v. 46.97 (SEM 1.75) and 65.98 (SEM 4.42) v. 115.07 (SEM 3.85), respectively (P<0.001); cross-sectional area (mm(2)) and moment of inertia (mm(4)) were 2.86 (SEM 0.19) v. 4.54 (SEM 0.17) and 1.27 (SEM 0.08) v. 3.03 (SEM 0.16), respectively (P<0.001). Significant effects were not evident in material properties. Parameters assessed normalized during re-feeding. These results suggest that the impaired mechanical femur competence in ND rats could be due to an altered bone mass and architectural distribution rather than to intrinsic quality. Re-feeding caused a reversal of the effects of food restriction on growth and bone parameters in ND rats.

Effect of nutritional stress on the hypothalamo-pituitary-gonadal axis in the growing male rat.

BACKGROUND/OBJECTIVE: Nutritional dwarfing (ND) consists of a decrease in weight and height gain and delayed onset of puberty. The aim of the present investigation was to study the modifications induced in male rats by the nutritional stress of a mere 20% reduction in food intake which, however, started immediately after weaning. MATERIALS AND METHODS: At weaning, male Wistar rats were divided into two groups: Control (C) and ND. C rats were fed ad libitum with a balanced rodent diet. ND received 80% of the diet consumed by C for 4 weeks (T4); then they were fed ad libitum for another 4 (T8) and 8 weeks (T12). The rats were studied at T0, T4, T8 and T12 for the effects of nutritional stress and refeeding on nutritional status, body composition, hypothalamic-pituitary-gonadal axis, and sperm morphology and concentration. RESULTS: ND body weight and length diminished vs. C (p < 0.001). ND body fat percentage decreased 40% (p < 0.001) without change in the percentage of body protein content. The hypothalamic content of LHRH did not change. However, FSH, LH and testosterone serum levels had significantly decreased (p < 0.001) at T4 in ND rats. A 48.4 % decrease in serum leptin in the ND group was observed at T4 (p < 0.05). The absolute testicular and seminal vesicle weight was significantly decreased by ND at T4 (p < 0.001). At T4 the percentage of anomalies of caudal spermatozoa increased in about 64% (p < 0.001) of ND vs. C rats, despite the unchanged sperm concentrations. All parameters normalized during refeeding. CONCLUSION: In this model, a decrease in leptin due to nutritional stress could be responsible, at least in part, for the inhibition of reproductive function. Refeeding normalized all parameters studied.

Enanismo por desnutricion: cronodinamia de los procesos metabolicos en ratas / Nutrition dwarfing: longitudinal analysis of anthropometric and metabolic parameters in rats

El enanismo por desnutrición es una enfermedad no orgánica, cuya causa es la reducción voluntaria o no intencional de la ingesta de alimentos, debida a hábitos alimentarios inapropiados, insatisfacción en el peso corporal o a inadecuadas dietas para adelgazar. Los pacientes con retardo en el crecimiento debido a una causa nutricional logram alcanzar un crecimiento que es el equilibrio entre el potencial genético para el crecimiento y la ingesta de nutrientes. Esta desaceleración en el crecimiento produce una adaptación metabólica que no se refleja en los parámetros bioquímicos tradicionales utilizados como marcados de malnutrición. El objetivo de nuestro trabajo fue comparar en un modelo experimental en ratas en crecimineto las posibles modificaciones en la utilización de sustrato endógeno (CC), el consumo de oxígeno (VO2) y la velocidad de crecimiento. Se emplearon 30 ratas macho de la cepa Wistar que al momento del destete se subdividieron en 3 grupos: control (C) y experimentales: E4 y E8. El grupo C recibió una dieta stock ad libitum. El E4 y E8 recibieron por cada 100 gr de peso corporal un 80 por ciento de la misma dieta durante 4 y 8 semanas, respectivamente. Durante el período de depleción nutricional se midieron los siguientes parámetros: 1) peso (P) y talla (T) corporales en función de la edad, 2) P/T Z Score, 3) Composición corporal (CC) por el EM-SCAN, TOBEC modelo SA 3000/3076, Springfield, USA, 4) VO2 por calorimetría indirecta (ECO-OXYMAX, Columbus Instruments). Se obtuvieron los siguientes resultados a las 4 y 8 semanas, respectivamente: 1) La categoría antropométrica (CA) de delgado (P/T Z Score: -0.70 + 0.43) y de desnutrido (P/T Z Score: -1.44 + 0.32), respectivamente, 2) La reserva lipídica fluctuó dentro del rango normal con una cronodinamia significativamente diferente respecto de la del C. 3) No hubo diferencia significativa del VO2 entre C, E4 y E8. Los resultados obtenidos sugieren que la ingesta crónica de una cantidad subóptima (80 por ciento) de una dieta balanceada afecta el crecimiento corporal sin alterar el desarrollo del individuo. (AU)

Enanismo por desnutricion: cronodinamia de los procesos metabolicos en ratas / Nutrition dwarfing: longitudinal analysis of anthropometric and metabolic parameters in rats

El enanismo por desnutrición es una enfermedad no orgánica, cuya causa es la reducción voluntaria o no intencional de la ingesta de alimentos, debida a hábitos alimentarios inapropiados, insatisfacción en el peso corporal o a inadecuadas dietas para adelgazar. Los pacientes con retardo en el crecimiento debido a una causa nutricional logram alcanzar un crecimiento que es el equilibrio entre el potencial genético para el crecimiento y la ingesta de nutrientes. Esta desaceleración en el crecimiento produce una adaptación metabólica que no se refleja en los parámetros bioquímicos tradicionales utilizados como marcados de malnutrición. El objetivo de nuestro trabajo fue comparar en un modelo experimental en ratas en crecimineto las posibles modificaciones en la utilización de sustrato endógeno (CC), el consumo de oxígeno (VO2) y la velocidad de crecimiento. Se emplearon 30 ratas macho de la cepa Wistar que al momento del destete se subdividieron en 3 grupos: control (C) y experimentales: E4 y E8. El grupo C recibió una dieta stock ad libitum. El E4 y E8 recibieron por cada 100 gr de peso corporal un 80 por ciento de la misma dieta durante 4 y 8 semanas, respectivamente. Durante el período de depleción nutricional se midieron los siguientes parámetros: 1) peso (P) y talla (T) corporales en función de la edad, 2) P/T Z Score, 3) Composición corporal (CC) por el EM-SCAN, TOBEC modelo SA 3000/3076, Springfield, USA, 4) VO2 por calorimetría indirecta (ECO-OXYMAX, Columbus Instruments). Se obtuvieron los siguientes resultados a las 4 y 8 semanas, respectivamente: 1) La categoría antropométrica (CA) de delgado (P/T Z Score: -0.70 + 0.43) y de desnutrido (P/T Z Score: -1.44 + 0.32), respectivamente, 2) La reserva lipídica fluctuó dentro del rango normal con una cronodinamia significativamente diferente respecto de la del C. 3) No hubo diferencia significativa del VO2 entre C, E4 y E8. Los resultados obtenidos sugieren que la ingesta crónica de una cantidad subóptima (80 por ciento) de una dieta balanceada afecta el crecimiento corporal sin alterar el desarrollo del individuo.