Group Of Sedentary Rats Research Articles

Secondary protein in the muscle of exercised rats that received creatine supplementation

ABSTRACT Introduction: Currently there is a lack of clarity around the use of Fourier transform infrared (FT-IR) spectroscopy to analyze the effect of creatine (Cr) supplementation on the secondary structures of skeletal muscle tissue protein subjected to exercise. Objective: The objective of this study was to evaluate the spectral characteristics of the tibialis anterior muscle in rats subjected to exercise in a pool and to Cr supplementation. Methods: Experiment 1. First, an experiment was conducted to ensure that FT-IR would be able to detect change in the secondary structures of skeletal muscle tissue protein in the group of sedentary rats (SED) and in the group of rats that received creatine supplementation (CRE). Experiment 2. Next, the effect of physical exercise on the spectral characteristics of muscle tissue, especially when compared to the groups without exercise practice, was examined. Results: It was possible to verify that the peaks centered on 1658 cm-1 (amide I) and 1546 cm-1 (amide II) are characteristic spectra and indicated as markers of protein content. Conclusion: Thus, FT-IR spectroscopy proved to be able to monitor changes in secondary structures of skeletal muscle protein in both animals that received supplements and in those subjected to exercise and both cases reconciled. Furthermore, the FT-IR technique proved to be a viable method for the nondestructive evaluation of skeletal muscle protein structures. Level of evidence II, Investigation of treatment results.

Stimulation of Peripheral Opioid Receptors during Acute Exercise Decreases Anxiety‐Like Behaviors in a Rat Model of Fibromyalgia

Patients with fibromyalgia often experience comorbid anxiety. Studies show exercise training can decrease pain in patients with fibromyalgia as well as decrease anxiety in healthy populations. Evidence suggests endorphins acting on opioid receptors contribute to exercise‐induced analgesia, but the role of these receptors on anxiety has not been determined in patients with fibromyalgia. The purpose of this study was to compare the effects of sedentary behavior and exercise training on anxiety in a rat model of fibromyalgia and to determine the contribution of peripheral opioid receptors to the exercise‐induced response. Female Sprague Dawley rats were induced with fibromyalgia by acidic saline injections (0.1 mL; pH 4). To assess anxiety‐like behaviors, rats were placed in an open field arena (90 × 90 cm) for two minutes. The arena floor was marked with 20.5 cm grids and the number of grids crossed during the observation period was recorded: a decrease in grids crossed indicated increased anxiety. A group of sedentary rats (SED; n=8) were tested for anxiety 5 days/week for 4 weeks. Another group of treadmill‐trained rats (NAL; n=5) received injections of the nonspecific opioid receptor antagonist naloxone (120 μg in 0.1 mL saline) in both gastrocnemius muscles ten minutes prior to moderate‐intensity (15 m/sec) treadmill running (4 weeks; 5 days/week; 30 min/day). NAL rats were observed in the open field arena before (PRE) and after (POST) each running bout. Mean grids crossed for SED rats in the open field were 21.3 ± 2.4 for week 1, 23.7 ± 2.9 for week 2, 29.7 ± 2.9 for week 3, and 28.0 ± 3.0 for week 4. While NAL PRE grids crossed were not different from SED grids crossed, the POST grids crossed for NAL rats decreased for all weeks: 16.5 ± 2.0 (PRE) and 10.1 ± 1.9 (POST) for week 1, 24.0 ± 1.9 (PRE) and 12.4 ± 1.4 (POST) for week 2, 21.8 ± 1.9 (PRE) and 10.4 ± 1.7 (POST) for week 3, and 23.6 ± 2.2 (PRE) and 13.2 ± 1.8 (POST) for week 4 (all p<0.05). Further, NAL POST grids crossed were significantly different from SED grids crossed for weeks 1, 2, 3 and 4 (p<0.05). While our data does not show a long‐term effect of exercise training on anxiety, it does suggest that stimulation of peripheral opioid receptors during acute exercise decreases anxiety‐like behaviors in the rat model. In conclusion, this study provides evidence that peripheral, in addition to central, opioid receptors contribute to an exercise‐induced decrease in anxiety and that even one exercise bout is beneficial when compared to sedentary behavior.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Moderate aerobic exercise reduces ozone‐produced oxidative stress in rats

Nitric oxide (NO) increases as a result of exercise adaptation. Moderate exercise produces oxidative stress (OS) that stimulates endogenous antioxidant capacity. We previously found that ozone (O3) produced OS and endothelial dysfunction in rats. O3 has been related to increased all‐cause mortality in humans, and aerobic exercise reduced this relationship. The goal of this study was to determine if moderate aerobic exercise reduced OS produced by O3. Male Wistar rats (230–250 g, 10‐weeks old, n=12) were trained to swim 90 min daily (14 days). Six of the rats were exposed to O3 (0.5 ppm, 4 h/day) one hour before exercise. Two groups of sedentary rats (n=6, each) were used as control, one of which was exposed to O3. At the end of the experiment blood was taken from the carotid artery and the animals were euthanized. Measurements were made on the plasma. O3 decreased reduced nitrates (indirect measurement of NO) and produced OS manifested by increased plasma malondialdehyde and 8‐isoprostane, and decreased superoxide dismutase (SOD) activity. Exercise significantly blocked O3 effects, although SOD was also decreased by exercise (the greater drop was in the O3 group).ConclusionAerobic exercise protects against OS produced by O3 and the effect is independent of SOD. Future studies will determine if exercise effects remain after long O3 exposure and if other antioxidants are responsible for those effects

Treadmill running protects spinal cord contusion from secondary degeneration

It is known that physical activity triggers changes in the central nervous system. Adult rats, trained on treadmills for 4 weeks, and a group of sedentary rats was submitted to contuse moderate spinal cord injury. A group of sedentary rats was submitted to a sham operation. The trained group continued running on treadmill after lesion for 4 weeks. Motor behavior evaluated by BBB score was smaller in the sedentary group compared to the trained rats by 7 days after lesion. Computerized activity monitor showed clear-cut differences in spontaneous motor parameters in trained rats only before lesion. After surgery, sedentary rats showed changes in motor parameters but not in later periods of analysis. Animals were euthanized by 28 days after surgery, and their spinal cords were processed for Nissl staining and immunohistochemistry. The number of the remaining neurons and the lesion areal and lesion volume fractions were obtained by stereological method. The number of the remaining neurons did not change after training. Lesion volume and lesion areal fraction per section were smaller in the trained group. Lesion index was more pronounced in the sedentary group. Microdensitometric image analysis demonstrated a microglial reaction, astroglial activation, and glial FGF-2 production more pronounced in the spinal cord of sedentary animals. GAP-43 was higher in caudal levels of contusion in the sedentary group. In conclusion, treadmill running may favor a better functional recovery in the acute period after spinal cord lesion and wound repair processes leading to neuroprotection.

Tentative de mise au point d'un modèle d'entraînement physique reproduisant chez le rat l'équivalent du syndrome de surentraînement

Resume Nous avons soumis des jeunes rats mâles Wistar a un entrainement physique modere (course sur tapis roulant motorise) de 4 semaines (6 j/semaine, 0,5–1 h/j, 20–30 m/min) suivi de 2 semaines supplementaires d'entrainement modere (1 h/j; rats E+, n=5) ou plus intense (4, 6–6, 4 h/j; rats E++, n=6). Les rats E+ et E++ ont ete sacrifies 18 heures apres la derniere seance d'effort epuisant (test mesurant l'endurance maximale), en meme temps que ceux d'un groupe de rats sedentaires (E-, n=6). Les resultats montrent une diminution de l'endurance maximale (>- 12%) lors de la 6e semaine chez les rats E++ (+9% chez les rats E+). De plus, on observe une diminution plus importante de la prise de poids corporel, de la cellularite du thymus et de la viabilite in vitro des splenocytes (cellules immunitaires de la rate) en reponse aux mitogenes (un index des fonctions de l'immunite cellulaire) chez les rats E++ que chez les rats E+ (respectivement, −19% versus −8%, −72% versus −35%, −44% versus −33%) (P 0,05), mais tres superieures a celles des rats E- (P 0,05). En conclusion, les resultats de ce travail indiquent que l'augmentation brutale du volume d'entrainement physique conduit a une diminution de la performance en endurance associee a une alteration de l'immunite cellulaire chez l'animal. Les systemes metabolique (metabolisme du glycogene) et neuroendocrinien (androgene sexuel) ne semblent pas affectes par cet entrainement intensif. Ces modifications immunitaires sont qualitativement distinctes (inverses) de celles observees lors d'un epuisement physique passager. Comme nous n'avons pas encore montre leur caractere durable et comme elles ne permettent que de dresser une description incomplete de l'equivalent animal du syndrome de surentrainement, de nouvelles tentatives de ce type devront etre menees avant de mettre au point un modele de surentrainement satisfaisant chez l'animal.