Eccentric exercise induces nitric oxide synthase expression through nuclear factor-kappaB modulation in rat skeletal muscle.

This study aimed to investigate the effect of eccentric exercise on the expression of the different nitric oxide synthase (NOS) isoforms in rat deep vastus lateralis muscle. Twenty-four rats were allocated to four experimental groups: rested control group, acutely exercised group after an intermittent downhill protocol for 90 min, acutely exercised group treated with pyrrolidine dithiocarbamate (100 mg/kg ip) for 24 and 1 h before the acute exercise bout, and acutely exercised group with a previous submaximal eccentric training of 8 wk. Acutely exercised rats showed increased levels of protein tyrosine nitration, NF-kappaB binding, and phospho-I kappaB alpha content. A significant increase was observed in mRNA level and protein content of neuronal NOS, inducible NOS, and endothelial NOS. The binding of NF-kappaB to the NOS isoform promoters, measured by a chromatin immunoprecipitation assay, was undetectable in rested rats, whereas it was evident in acutely exercised animals. All of these effects were partially abolished by pyrrolidine dithiocarbamate treatment and by training. In summary, our findings provide a direct link between the NF-kappaB signaling cascade and NOS expression in skeletal muscle following eccentric exercise and suggest a modulation of the expression of the three NOS isoforms by this transcription factor.

Sulforaphane treatment protects skeletal muscle against damage induced by exhaustive exercise in rats.

Sulforaphane (SF), one of the most important isothiocyanates in the human diet, present in cruciferous vegetables, is known to have chemopreventive activities in different tissues. No data are available on its effects in the prevention of skeletal muscle damage. In this study, we investigated the potential protective effects of SF treatment on muscle damage and oxidative stress induced by an acute bout of exhaustive exercise in rats. Male Wistar rats were treated with SF (25 mg/kg body wt ip) for 3 days before undergoing an acute exhaustive exercise protocol in a treadmill (+7% slope and 24 m/min). Acute exercise resulted in a significant increase in plasma lactate dehydrogenase (LDH) and creatine phosphokinase (CPK) activities. It also resulted in a significant increase in thiobarbituric acid-reactive substances, in a significant decrease in tissue total antioxidant capacity, and in a significant decrease in NAD(P)H:quinone oxidoreductase 1 (NQO1) expression and activity in vastus lateralis muscle. SF treatment significantly increased muscle NQO1, glutathione-S-transferase, and glutathione reductase expression and activity, with no effect on glutathione peroxidase and thioredoxin reductase. The observed SF-induced upregulation of phase II enzymes was accompanied by a significant increase in nuclear erythroid 2 p45-related factor 2 expression and correlated with a significant increase in total antioxidant capacity and a decrease in plasma LDH and CPK activities. Our data demonstrate that SF acts as an indirect antioxidant in skeletal muscle and could play a critical role in the modulation of the muscle redox environment, leading to the prevention of exhaustive exercise-induced muscle damage.

Is the Mediterranean lifestyle still a reality? Evaluation of food consumption and energy expenditure in Italian and Spanish university students.

OBJECTIVE: To evaluate the correspondence of diet and lifestyle to the Mediterranean model in two groups of Italian and Spanish university students. DESIGN: A cross-sectional nutritional survey to determine BMI, dietary habits (FFQ), energy daily expenditure and lifestyle (SenseWear Armband; BodyMedia Inc.), and to define the Mediterranean diet quality index (MDQI) in the different student groups. SETTING: Bologna (Italy) and León (Spain). SUBJECTS: The survey was carried out on 210 (105 Italian; 105 Spanish) university students (mean age 27.0 (sd 3.8) years) of two different Mediterranean areas, Bologna (Italy) and León (Spain). RESULTS: The frequency of consumption of some food groups showed differences related to nationality and gender. Some classic Mediterranean foods such as cereals and vegetables were generally consumed more frequently by Italian students; others such as fish and pulses by Spanish students. Percentage of overweight was higher among Spanish students in spite of their higher physical activity level. CONCLUSION: Young generations seem to give up the traditional Mediterranean dietary pattern, adopting new dietary trends. Overweight appears to be related not only to physical activity level, but also to the poor MDQI.

High-protein-PUFA supplementation, red blood cell membranes, and plasma antioxidant activity in volleyball athletes.

The authors evaluated the role of a high-protein, low-calorie, polyunsaturated fatty-acid (PUFA) -supplemented diet on anthropometric parameters, erythrocyte-membrane fatty-acid composition, and plasma antioxidant defenses of nonprofessional volleyball athletes. The athletes were divided in two groups: One (n = 5) followed the Mediterranean diet, and the other (n = 6) followed a high-protein, low-calorie diet with a 3-g/day fish-oil supplementation. All the athletes had anthropometric measurements taken, both at the beginning and at the end of the study, which lasted for 2 months. Body-mass index and total body fat were significantly diminished in the second group, while they remained unchanged in the first. Plasma total antioxidant activity (TAA) was significantly increased in the plasma of both groups, with no differences between the groups, suggesting that physical activity, not the different diets, is the main contributor to the increase of plasma TAA. The second group showed a significant increase in erythrocyte-membrane PUFA content and in the unsaturation index value (UI) because of the fish-oil supplementation.A high-protein, low-carbohydrate, fish-oil-supplemented diet seems to be useful only when the aim of the diet is to obtain weight loss in a short-term period. The significant increase in the UI of erythrocyte membranes indicates the potential for harm, because a high intake of PUFA might increase susceptibility to lipid peroxidation not counterbalanced by a higher increase in TAA. Adherence to the Mediterranean diet seems to be the better choice.

Dietary habits and related psychological and social factors: influence on the body weight of elementary school children.

This article studies the alimentary habits of children in relation to their body mass index (BMI) and food preferences, and to underline the influences of cultural and social aspects. The investigation tested 198 children (90 male and 108 female) from Cento (Ferrara), using food frequency questionnaires that were completed by the children. Subjects were subdivided into three groups based on their BMI--normal weight, overweight and underweight--taking into consideration their food frequency and preferences. The correlations between the BMI of children, mother's geographic origin and cultural level revealed differences between boys and girls. The variability of results does not allow precise correlations to be made between food frequency and children's weight, psychological and social aspects. Some incorrect dietary habits were revealed in the overweight and underweight groups. These could be controlled for and corrected by an alimentary education programme.