Search results for " CONDITIONING"
showing 10 items of 400 documents
Brain BDNF Levels Elevation Induced by Physical Training is Reduced after Unilateral Common Carotid Artery Occlusion in Rats
2014
International audience; We investigated the contribution of blood flow elevation in the cerebrovasculature to physical training-induced brain-derived neurotrophic factor (BDNF) levels elevation in the brain. Brain-derived neurotrophic factor protein levels were measured in the motor cortex 24 h after the last session of a forced treadmill walking (30 minutes a day, 18 m/minute for 7 consecutive days). Unilateral common carotid artery occlusion and modulation of exercise intensity (0 versus -10% inclination of the treadmill) were used as strategies to reduce the (normal) elevation of flow in the cerebrovasculature occurring during exercise. Administration of N-nitro-L-arginine methyl ester (…
The Impact of Fluid Loss and Carbohydrate Consumption during Exercise, on Young Cyclists’ Fatigue Perception in Relation to Training Load Level
2021
High-level young athletes need to face a wide spectrum of stressors on their journey to élite categories. The aims of the present study are (i) to evaluate session rate of perceived exertion (sRPE) at different training impulse (TRIMP) categories and the correlations between these two variables and, (ii) evaluate the correlations between sRPE, fluid loss, and carbohydrate consumption during exercise. Data on Edward’s TRIMP, sRPE, body mass loss pre- and post- exercise (∆), and carbohydrate consumption (CHO/h) during exercise have been acquired from eight male junior cyclists during a competitive season. One-way ANOVA and correlation analysis with linear regression have been performed on acq…
Protection effect of endurance training against reoxygenation-induced injuries in rat heart
1990
Endurance training by swimming (219-229 h) resulted in a significant protection against hypoxia/reoxygenation-induced injuries in Langendorff-perfused rat hearts. The protection was manifested as improved flow characteristics and a smaller release of creatine kinase into the perfusate. The concentration of thiobarbituric acid reactive substances (TBARS) was lower in the trained than in the respective control hearts. The trained hearts also showed a lower reoxygenation-induced increase in TBARS. The myocardium of the right ventricle and that of the left subepimyocardium were the most affected by reoxygenation. The swimming program induced a decrease in the activities of catalase and glutath…
Spatial cues are relevant for learned preference/aversion shifts due to amino-acid deficiencies.
1998
Rats are able to choose appropriately between two versions of a novel diet, when one is amino-acid devoid and the other corrected. Recognition of the deficiency has been reported to occur within hours and to initiate a strong conditioned aversion. For that purpose the rat can use either oro-sensory cues or another alternative as the conditioned stimulus (CS) with which to associate the unconditioned stimuli (US) of either the adequate diet or the devoid diet. The present investigation was designed to determine whether rats have the ability to use place as a cue in amino-acid preference/aversion. In order to avoid interfering with any other than spatial sensory discrimination between the dev…
The involvement of MMP-2 and MMP-9 in heart exercise-related angiogenesis
2013
Background Little is known about the involvement of matrix metalloproteinases (MMPs) in cardiac vascular remodelling induced by exercise. Our aim was to evaluate and localize MMP-2 and MMP-9’s activities in relation to capillary proliferation in mouse hearts trained for 15, 30 and 45 days. Methods Sixty-three mice were randomly assigned to 7 groups: four control sedentary groups (C0, C15, C30 and C45) and three groups trained by an endurance protocol (T15, T30 and T45). MMP-2 and MMP-9 were examined with zymography and immunostaining analyses. Capillary proliferation was evaluated counting the number of CD31-positive cells. Results Different activity patterns of the latent form of both MMPs…
?-Glucuronidase activity in trained red and white skeletal muscle of mice
1978
We studied the effects of prolonged running exercise (5 days a week, 1.5 h per day at a speed of 17.6 m/min) on the activity of some acid hydrolases (beta-glucuronidase, beta-N-acetylglucosaminidase, acid phosphatase and cathepsin D) and three enzymes of energy metabolism (cytochrome c oxidase, lactate dehydrogenase and creatine kinase) in the distal and in the proximal, the predominantly white and red parts, respectively, of the vastus lateralis-muscle from mice. The acid hydrolase activity levels were 1.24--1.69 higher in untrained red muscle compared to untrained white muscle. The light training applied increased the activity of beta-glucuronidase in both red and white muscle. No other s…
Effect of chronic exercise on glucose uptake and activities of glycolytic enzymes measured regionally in rat heart.
1989
Regional glucose uptake in perfused hearts, and the activities of several glycolytic enzymes contributing to the glucose metabolism in perfused and nonperfused hearts were studied in male and female rats after 8–9 weeks of swimming training. The left ventricular glucose uptake showed a transmural gradient in the sedentary animals, the subendocardial uptake being 30% and 12% higher than that of the subepicardial layer in the males and females, respectively. Swimming exercise abolished the left ventricular glucose uptake gradient in male rats, and in female rats an opposite gradient was found, the subepicardial uptake being 23% higher than the subendocardial uptake. The activities of phosphof…
Muscle enzyme adaptations to added load during training and nontraining hours in rats.
1991
The effects of added load (20% of body mass) on the selected enzyme activities of red and white quadriceps femoris (QF), soleus, and gastrocnemius muscles of rats were studied. The rats were divided into sedentary control (SC), sedentary control with added load (SC+AL), endurance training (ET), and endurance training with added load (ET+AL) groups (n = 10 rats/group). After 6 wk, the SC+AL group had 57% higher (P less than 0.001) beta-glucuronidase (beta-GU) activity and 24% lower (P less than 0.05) citrate synthase activity in white QF than SC. Citrate synthase activity was also decreased in red QF (P less than 0.05) after the added load was used during nontraining hours. The training wit…
Physical training and connective tissues in young mice-heart
1976
The effect of physical training on the chemical properties of the heart tissues was studied in male mice of NMRI-strain. The mice to be trained and their controls were about 2 weeks old at the beginning of the training, which took place on 5 degrees inclined treadmill 5 days a week for 3-22 weeks. The duration of daily exercise was progressively increased over the first 3 weeks. The final daily exercise bouts were 50 and 80 min for moderate programs and 180 min for the intensive program at a speed of 30 cm/s. The whole heart or the ventricles were used for the analyses. We found no significant changes related to training in the concentrations of nitrogen, hexosamines, and hydroxyproline bot…
Pavlovian conditioning of corticotropin-releasing factor-induced increase of blood pressure and corticosterone secretion in the rat
1992
Corticotropin-releasing factor (CRF) is clearly involved in the central regulation of the pituitary-adrenal axis and, moreover, of autonomic nervous system functions. Enhanced sympathetic activity with subsequent increases in blood pressure and heart rate and attenuation of the baroreceptor reflex results from the intracerebroventricular (i.c.v.) administration of CRF. Additionally, the peptide has a variety of potent effects on behavioural responses in animals similar to those observed after an experimentally evoked stress. It was therefore of obvious interest to examine whether CRF is a possible mediator of the learning processes associated with physiological stress reaction patterns. Thi…