Effects of Dietary Nitrate Supplementation on Performance and Muscle Oxygenation during Resistance Exercise in Men

The purpose of the current study was to assess the effects of acute and short-term nitrate (NO3−)-rich beetroot juice (BR) supplementation on performance outcomes and muscle oxygenation during bench press and back squat exercise. Fourteen recreationally active males were assigned in a randomized, double-blind, crossover design to supplement for 4 days in two conditions: (1) NO3−-depleted beetroot juice (PL; 0.10 mmol NO3− per day) and (2) BR (11.8 mmol NO3− per day). On days 1 and 4 of the supplementation periods, participants completed 2 sets of 2 × 70%1RM interspersed by 2 min of recovery, followed by one set of repetitions-to-failure (RTF) at 60%1RM for the determination of muscular power, velocity, and endurance. Quadriceps and pectoralis major tissue saturation index (TSI) were measured throughout exercise. Plasma [NO3−] and nitrite ([NO2−]) were higher after 1 and 4 days of supplementation with BR compared to PL (p \u3c 0.05). Quadriceps and pectoralis major TSI were not different between conditions (p \u3e 0.05). The number of RTF in bench press was 5% greater after acute BR ingestion compared to PL (PL: 23 ± 4 vs. BR: 24 ± 5, p \u3c 0.05). There were no differences between BR and PL for RTF for back squat or power and velocity for back squat or bench press (p \u3e 0.05). These data improve understanding on the ergogenic potential of BR supplementation during resistance exercise

Перспективы развития фундаментальных наук. Т. 5 : Экономика и управление

Сборник содержит труды участников XV Международной конференции студентов, аспирантов и молодых учёных «Перспективы развития фундаментальных наук», представленные на секции «Экономика и управление». Для студентов, аспирантов, молодых ученых и преподавателей, специализирующихся в области цифровой экономики, институциональной и отраслевой экономики, инновационной политики и предпринимательства, налоговой политики и регулирования, финансов, денежного обращения и кредита, учёта, анализа и аудита, статистики, менеджмента, экономики труда, математических методов и информационных технологий в экономике, менеджменте и бизнесе, развития системы государственного и муниципального управления, междисциплинарного исследования в экономике, а также международных экономических отношений

Protective effect of leptin against ischemia-reperfusion injury in the rat small intestine

BACKGROUND: The small intestine is extremely sensitive to ischemia-reperfusion (I/R) injury and a range of microcirculatory disturbances which contribute to tissue damage. Previous studies have shown that leptin plays an important physiological role in the microvasculature. The aim of this study was to evaluate the protective effects of leptin in I/R – induced mucosal injury in the small intestine. METHODS: Forty rats were divided into 5 groups (n = 8). Group I was subjected to a sham operation. Following mesenteric ischemia in group II (control); physiologic saline 1 cm(3), in group III; leptin 100 μg/kg, and physiologic saline 1 cm(3), in group IV; N(G)-L-arginine methyl ester (L-NAME) 20 mg/kg, and physiologic saline 1 cm(3), in group V; leptin 100 μg/kg, L-NAME 20 mg/kg, and physiologic saline 1 cm(3 )were given intra-peritoneally. In these groups, an I/R procedure was performed by occlusion of the superior mesenteric artery for 45 min followed by 120 min reperfusion. After reperfusion, the small intestines were resected for malondialdehyde (MDA) and nitric oxide (NO) concentration and histopathologic properties. Mucosal lesions were scored between 0 and 5. Tissue MDA and NO concentration and histopathologic grades were compared statistically. RESULTS: Tissue MDA level significantly increased (P < 0.05), tissue NO level significantly decreased in group V animals, compared to group III animals respectively (P < 0.001). Histopathologically, intestinal injury significantly decreased in the leptin treated ischemic group. CONCLUSION: Leptin can be used safely in mesenteric occlusive diseases, since it induces NO formation and release in mesenteric vessels

Initial intramuscular perfusion pressure predicts early skeletal muscle function following isolated tibial fractures

<p>Abstract</p> <p>Background</p> <p>The severity of associated soft tissue trauma in complex injuries of the extremities guides fracture treatment and decisively determines patient's prognosis. Trauma-induced microvascular dysfunction and increased tissue pressure is known to trigger secondary soft tissue damage and seems to adversely affect skeletal muscle function.</p> <p>Methods</p> <p>20 patients with isolated tibial fractures were included. Blood pressure and compartment pressure (anterior and deep posterior compartment) were measured continuously up to 24 hours. Corresponding perfusion pressure was calculated. After 4 and 12 weeks isokinetic muscle peak torque and mean power of the ankle joint in dorsal and plantar flexion were measured using a Biodex dynamometer.</p> <p>Results</p> <p>A significant inverse correlation between the anterior perfusion pressure at 24 hours and deficit in dorsiflexion at 4 weeks was found for both, the peak torque (R = -0.83; p < 0.01) and the mean power (R = -0.84; p < 0.01). The posterior perfusion pressure at 24 h and the plantar flexion after 4 weeks in both, peak torque (R = -0.73, p =< 0.05) and mean power (R = -0.7, p =< 0.05) displayed a significant correlation.</p> <p>Conclusion</p> <p>The functional relationship between the decrease in intramuscular perfusion pressures and muscle performance in the early rehabilitation period indicate a causative and prognostic role of early posttraumatic microcirculatory derangements and skeletal muscle function. Therapeutic concepts aimed at effective muscle recovery, early rehabilitation, and decreased secondary tissue damage, should consider the maintenance of an adequate intramuscular perfusion pressure.</p

Serum Levels of Soluble Adhesion Molecules as Prognostic Factors for Acute Liver Failure

Background/Aims: In patients with septic shock, the degree of liver dysfunction is correlated with serum levels of soluble intercellular adhesion molecule (sICAM)-1. We aimed to assess the usefulness of serum levels of soluble adhesion molecules as prognostic factors for acute liver failure (ALF). Methods: Serum levels of soluble platelet endothelial cell adhesion molecule (sPECAM)-1, sICAM-3, soluble endothelial (sE) selectin, sICAM-1, soluble platelet selectin, and soluble vascular cell adhesion molecule-1 on admission were measured in 37 ALF patients and 34 healthy controls. Results: Twenty-two ALF patients (59%) reached to fatal outcomes. Serum levels of sPECAM-1, sICAM-3, sE-selectin and sICAM-1 were higher in ALF patients than healthy controls. In 37 ALF patients, by the multivariate logistic regression analysis, ratio of direct to total bilirubin (per 0.1 increase; OR 0.11, 95% CI 0.01-0.99), serum sPECAM-1 level (per 100 ng/ml increase; OR 4.37, 95% CI 1.23-15.5) and serum sICAM-1 level (per 100 ng/ml increase; OR 0.49, 95% CI 0.27-0.89) were associated with fatal outcomes. Using receiver operating characteristics curve, each area under the curve of serum sPECAM-1 and sICMA-1 levels as prognostic factors was 0.71 and 0.74, respectively. Conclusion: Serum sPECAM-1 and sICAM-1 levels may be useful for predicting the prognosis of ALF