Biomedical subjects

C Y Guezennec

Publications and source records attributed to C Y Guezennec.

At least 19 recordsLinked to original sources

PubMed2005

Swimming and cycling overloaded training in triathlon has no effect on running kinematics and economy.

The aim of the study was to verify whether an overloaded training (OT) in triathlon deteriorates running kinematics (RK) and running economy (RE). Thirteen well-trained male long-distance triathletes (age: 28.1 +/- 4.3 yrs; V.O (2max): 65.0 +/- 3.1 ml O (2) . min (-1) . kg (-1)) were divided into two groups: completed an individualized OT program (OG; n = 7) or maintained a normal level of training (NT) (CG; n = 6) for a duration of 3 weeks. Every week, each triathlete completed a standardized questionnaire to quantify the influence of training loads on mood state. To reach OT, total training load (h . 3 wk (-1)) was increased by 24 %; swimming and cycling total volumes were increased by 46 and 57 %, respectively, but the distance run was not modified in order to limit the risk of injuries. RK and RE were determined on treadmill test at 12 km . h (-1) before and after the 3 weeks. The 3-week swimming and cycling OT in triathlon was sufficiently stressful to alter mood state but not to deteriorate the running kinematics and economy parameters in our previously well-trained male long-distance triathletes.

Adult↗

PubMed2004

Intense training: mucosal immunity and incidence of respiratory infections.

This investigation examined the impact of a multistressor situation on salivary immunoglobulin A (sIgA) levels, and incidence of upper respiratory tract infection (URTI) during the French commando training (3 weeks of training followed by a 5-day combat course). For the URTI, the types of symptoms were classified according to the anatomical location of the infection. Saliva samples were collected (8 a.m.) from 21 males [21 (2) years] before entry into the commando training, the morning following the 3 weeks of training, after the 5-day combat course, and after 1 week of recovery. sIgA, protein and cortisol concentrations were measured. Symptoms of URTI were recorded during the study from health logs and medical examinations. After the 3 weeks of training, the sIgA concentration was not changed, although it was reduced after the 5-day course [from 120 (14) mg l(-1) to 71 (9) mg l(-1), P<0.01]. It returned to pre-training levels within a week of recovery. The incidence of URTI increased during the trial (chi(2)=53.48; P<0.01), but was not related to sIgA. Among the 30 episodes of URTI reported, there were 12 rhino-pharyngitis, 6 bronchitis, 5 tonsillitis, 4 sinusitis and 3 otitis. Cortisol levels were raised after the 3-week training (P<0.01), dropping below baseline after the combat course (P<0.01). Stressful situations have an adverse effect on mucosal immunity and incidence of URTI. However, the relationship between sIgA and illness remained unclear. The large proportion of rhino-pharyngitis indicated that the nasopharyngeal cavity is at a higher risk of infection.

Adaptation, Physiological↗

PubMed2004

Influence of energy deficiency on the insulin-like growth factor I axis in a military training program.

The aim of this study was to determine wether continuous heavy physical activities as well as lack of food and sleep during military training (three weeks of conditioning followed by a five-day combat course) alter serum concentrations of IGF-I and/or its binding proteins, evaluating the relationship to metabolic changes. Before and after training, we measured serum levels of both total and free IGF-I, IGFBP-1 and IGFBP-3 as well as plasma levels of branched-chain amino acids (valine, leucine and isoleucine) and glucose from 26 cadets (21 +/- 2 yr). Total and free IGF-I levels were decreased after training from 228 +/- 12 to 160 +/- 7 ng/ml and from 0.80 +/- 0.08 to 0.52 +/- 0.06 ng/ml, p < 0.001 respectively) as well as IGFBP-3 (p < 0.001), while IGFBP-1 levels were increased (p < 0.001). BCAA levels were decreased from 245.4 +/- 7.5 to 215.9 +/- 5.1 micromol/l, p < 0.001, while those of glucose remained unchanged. There were correlations between changes in total IGF-I and IGFBP-3 (p < 0.05) and between free IGF-I and IGFBP-1 (p < 0.01). Several correlations appeared between changes in all the components of the IGF-I axis and branched-chain amino acids. We concluded that responses of the IGF-I system during an intense training could represent an adaptative response to the encountered energy deficiency, resulting a diversion of substrate from growth to acute metabolic needs.

Adult↗

PubMed2004

Metabolic and vascular support for the role of myoglobin in humans: a multiparametric NMR study.

In human muscle the role of myoglobin (Mb) and its relationship to factors such as muscle perfusion and metabolic capacity are not well understood. We utilized nuclear magnetic resonance (NMR) to simultaneously study the Mb concentration ([Mb]), perfusion, and metabolic characteristics in calf muscles of athletes trained long term for either sprint or endurance running after plantar flexion exercise and cuff ischemia. The acquisitions for (1)H assessment of Mb desaturation and concentration, arterial spin labeling measurement of muscle perfusion, and (31)P spectroscopy to monitor high-energy phosphate metabolites were interleaved in a 4-T magnet. The endurance-trained runners had a significantly elevated [Mb] (0.28 +/- 0.06 vs. 0.20 +/- 0.03 mmol/kg). The time constant of creatine rephosphorylation (tauPCr), an indicator of oxidative capacity, was both shorter in the endurance-trained group (34 +/- 6 vs. 64 +/- 20 s) and negatively correlated with [Mb] across all subjects (r = 0.58). The time to reach maximal perfusion after cuff release was also both shorter in the endurance-trained group (306 +/- 74 vs. 560 +/- 240 s) and negatively correlated with [Mb] (r = 0.56). Finally, Mb reoxygenation rate tended to be higher in the endurance-trained group and was positively correlated with tauPCr (r = 0.75). In summary, these NMR data reveal that [Mb] is increased in human muscle with a high oxidative capacity and a highly responsive vasculature, and the rate at which Mb resaturates is well correlated with the rephosphorylation rate of Cr, each of which support a teleological role for Mb in O(2) transport within highly oxidative human skeletal muscle.

Exercise↗

PubMed2003

The effects of long-term adrenalectomy on 5-HT1B receptors mRNA expression in cerebellum, striatum, frontal cortex and hippocampus of rats.

The brain serotonin (5-HT) system and circulating corticosteroids are in close interaction and both implicated in the pathogenesis of affective disorders. We evaluated the effects of adrenalectomy (ADX) on 5-HT(1B) receptors mRNA expression in cerebellum, frontal cortex, striatum and hippocampus in rats, using the RNase protection assay technique. Eight weeks after bilateral adrenalectomy, 5-HT(1B) receptor mRNA levels were decreased in the cerebellum and in the frontal cortex. The expression of 5-HT(1B) receptors mRNA was unchanged in the hippocampus and in the striatum. This data indicates regional differences in the effects of long term adrenalectomy on the expression of 5-HT(1B) receptors.

Adrenalectomy↗

PubMed2002

Effects of moderate and intensive training on the hypothalamo-pituitary-adrenal axis in rats.

The influence of the two distinct training programmes, moderate (M) and intensive (I), on hypothalamo-pituitary-adrenal (HPA) axis was investigated, in rats. Changes in plasma concentrations of adrenocorticotropin hormone (ACTH) and corticosterone were followed in response to (i) a 60-min acute running session performed on 2nd, 4th and 6th of the seven training weeks (ii) an acute restraint stress of 40 min applied after the final training programme. After 2nd, 4th and 6th week of the two training programmes, a 60-min running resulted in an enhanced secretion of ACTH and corticosterone, compared with both the baseline values (i.e. before running) and to the sedentary (S) group. However, on 4th and 6th weeks compared with 2nd week, ACTH and corticosterone remained elevated in intensive group when they are significantly reduced in moderate group. We could suggest that a moderate training resulted in an adapted hormonal response whereas a deadapted process occurred for the intensive programme. The day after the last training session, basal ACTH, corticosterone and corticosteroid-binding globulin (CBG) capacity were not affected by training. Hypothalamic corticotropin-releasing factor tissue-content (CRF) was increased significantly in the two trained groups. When compared with the sedentary group, the body weight of the rats in the two trained groups was significantly decreased with a total adrenal mass increasing but only in intensive group. The surimposed restraint stress resulted in significant increases in plasma ACTH and corticosterone both in trained and in sedentary animals. This result suggests that the adapted HPA axis response induced by both a moderate and intensive training do not prevent against the effects of a novel stress such as restraint stress.

Adrenal Glands↗

PubMed2002

Evidence that brain glucose availability influences exercise-enhanced extracellular 5-HT level in hippocampus: a microdialysis study in exercising rats.

The relationship between brain glucose and serotonin is still unclear and no direct evidence of an action of brain glucose on serotonergic metabolism in central fatigue phenomena has been shown yet. In order to determine whether or not brain glucose could influence the brain 5-hydroxytryptamine (5-HT) system, we have monitored in microdialysis the effects of a direct injection of glucose in rat brain hippocampus on serotonergic metabolism [i.e. 5-HT, 5-hydroxyindoleacetic acid (5-HIAA) and tryptophan (TRP)], during high intensive treadmill running. The injection was performed just before and after exercise. We have shown that glucose induced a decrease of brain 5-HT levels to a minimum of 73.0 +/- 3.5% of baseline after the first injection (P < 0.01) and to 68.5 +/- 5.5% of baseline after the second injection (P < 0.01) and consequently prevented the exercise-induced 5-HT enhanced levels. We have observed the same phenomenon concerning the 5-HIAA, but brain TRP levels were not decreased by the injections. In conclusion, this study demonstrates that brain glucose can act on serotonergic metabolism and thus can prevent exercise-induced increase of 5-HT levels. The results also suggest that extracellular brain glucose does not act on the synthesis way of 5-HT, but probably on the release/reuptake system.

Animals↗

PubMed2001

Endurance training effects on 5-HT(1B) receptors mRNA expression in cerebellum, striatum, frontal cortex and hippocampus of rats.

The 5-HT(1B) receptors are the predominant auto- and heteroreceptors located on serotonergic and non-serotonergic terminals where they regulate the neuronal release of neurotransmitters. The present study investigated the effects of a 7 week period of physical training on the expression of cerebral 5-HT(1B) receptors by measuring corresponding mRNA levels in rat. Using RNase protection assay technique, we have observed no change in 5-HT(1B) receptor mRNA levels in the striatum and in the hippocampus after moderate as well as after intensive training. In contrast, a significant decrease in 5-HT(1B) receptor mRNA levels was observed in cerebellum of intensively trained rats. Moreover, in frontal cortex, a significant decrease in 5-HT(1B) receptors mRNA level occurred in both groups of trained rats. These data suggest the existence of regional differences in the effect of physical exercise on the expression of 5-HT(1B) receptors.

Animals↗

PubMed2001

Site-dependent effects of an acute intensive exercise on extracellular 5-HT and 5-HIAA levels in rat brain.

Previous neurochemical studies have reported different pattern of 5-HT release during exercise varying across either exercise conditions or forebrain sites. This in vivo microdialysis study is the first to examine the impact of an acute intensive treadmill running (2 h at 25 m.min(-1), which is close to exhaustion time), on extracellular 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) levels in two different brain areas in rats, the ventral hippocampus and the frontal cortex. Hippocampal and cortical 5-HT levels increased significantly after 90 min of exercise and were maximal in the first 30 min of recovery. Thereafter, cortical 5-HT levels followed a rapid and significant decrease when hippocampal levels are still maximal. During exercise, changes in extracellular 5-HIAA levels paralleled 5-HT changes, but showed no difference between the two brain areas during recovery. Thus, an intensive exercise induces a delayed increase in brain 5-HT release but recovery seems to display site-dependent patterns.

Animals↗

PubMed2001

Exercise-induced changes in brain glucose and serotonin revealed by microdialysis in rat hippocampus: effect of glucose supplementation.

The aim of this study was to assess extracellular glucose changes in hippocampus in response to physical exercise and to determine the influence of glucose supplementation. In the same time, we have observed the changes in serotonin, in order to study the relationship between glucose and serotonin during exercise. Both glucose and serotonin were assessed using microdialysis. Exercise induced an increase in extracellular glucose levels over baseline during exercise to 121.1 +/- 3.0% (P < 0.001), then a decrease to baseline during recovery. The serotonin followed glucose changes during the first 90 min of exercise, but followed a different pattern during recovery, increasing to a maximum of 129.9 +/- 7.0% after 30 min of recovery (P < 0.001). When a 15% glucose solution was infused (10 microL x min(-1)) during exercise and recovery, blood glucose concentration was increased, but extracellular brain glucose decreased to reach a minimum of 73.3 +/- 4.6% after 90 min of recovery (P < 0.001). Serotonin was always the mirror-reflect of cerebral glucose, with a maximum increase of 142.0 +/- 6.9% after 90 min of recovery (P < 0.001). These results show that exercise induces changes in brain glucose and 5-hydroxytryptamine (5-HT) levels, which were dramatically modified by glucose infusion. Taking into account the implication of brain 5-HT in central fatigue, they suggest that if glucose supplementation, before and during exercise, undoubtedly increase performance because of its peripheral positive action, it would have a negative impact on the quality of recovery after the end of the exercise.

Animals↗

PubMed2001

Evidence that the branched-chain amino acid L-valine prevents exercise-induced release of 5-HT in rat hippocampus.

The branched-chain amino acid L-valine competes with tryptophan for transport into the brain and has previously been shown to decrease brain 5-HT synthesis. The purpose of this study was to assess, using a combined venous catheterization and in vivo microdialysis method, the effect of pre-exercise L-valine administration on 5-hydroxytryptamine (5-HT) metabolism in the ventral hippocampus of rats submitted to an acute intensive treadmill running (120 min at 25 m x min(-1) followed by 150 min of recovery). The presented results include measurement of extracellular tryptophan (TRP), the 5-HT precursor, and extracellular 5-hydroxyindoleacetic acid (5-HIAA), the 5-HT metabolite. The data clearly demonstrate that exercise induces 5-HT release in the rat hippocampus: in control group, hippocampal 5-HT levels increase from 123.7 +/- 6.4% at the end of exercise to 133.9 +/- 6.4% after 60 min of recovery. Moreover, two hours of intensive running induced significant increases both in extracellular TRP levels (from 120 min of exercise to 30 min of recovery) and 5-HIAA levels (from 90 min of exercise to 90 min of recovery). Pre-exercise administration of L-valine prevents significantly the exercise-induced 5-HT release: 5-HT levels are maintained to baseline during exercise and recovery. With regard to the competitive effect of L-valine with TRP, we could observe a treatment-induced decrease in brain TRP levels (from 120 min of exercise to the end of recovery). Besides, L-valine does not prevent exercise-induced increase in 5-HIAA levels. The present study evidences that an acute intensive exercise stimulates 5-HT metabolism in the rat hippocampus, and that a pre-exercise administration of L-valine prevents, via a limiting effect on 5-HT synthesis, exercise-induced 5-HT release. This study provides some anwers to previous human and animal investigations, showing physiological and psychological benefits of branched-chain amino acids supplementation on performance.

Analysis of Variance↗

PubMed2001

[Doping: effectiveness, consequences, prevention].

The use of doping is linked with the history of sports. Doping abuse escalated until the mid sixties when government and sports authorities responded with antidoping laws and drug testing. Today, the details of substances detected in controls give a good indication on the importance of doping use. Three classes of pharmaceuticals account for most of the positive controls. They are anabolic steroids, stimulants and narcotics. Their use can be related with the goal of the athletes. Anabolic steroids are mainly used in sports such as bodybuilding or weight lifting in order to develop strength. Stimulants are used in sports were speed favors performance. All the products that enhance blood oxygen transportation are used in endurance sports, their efficacy is not scientifically demonstrated, but their use does result in real risks. Several studies have evidenced the medical problems resulting from prolonged doping. Doping control is impaired by the fact that many products now used, e.g. EPO or rhGH, are not detectable. Regular medical examination of athletes could help prevent use of doping.

Anabolic Agents↗

PubMed2000

Effects of physical training on functional activity of 5-HT1B receptors in rat central nervous system: role of 5-HT-moduline.

The effect of physical exercise was examined on the sensitivity of 5-HT1B receptors and on 5-HT-moduline tissue concentration in the central nervous system of rats. Rats were trained for 7 consecutive weeks to run on a treadmill. Three groups of animals were selected: group 1, sedentary rats (controls); group 2, animals running for 1 h at 18 m/min for 5 days per week (moderate training) and group 3, animals running for 2 h, at 30 m/min on a 7% grade for 5 days per week (intensive training). The animals were sacrificed 24 h after the last running. Rat brains were dissected out to obtain hippocampus and substantia nigra and kept at -80 degrees C until use. 5-HT1B receptor activity was determined by studying [35S]GTPgammaS binding in a substantia nigra membrane preparation from individual animals, after stimulation by a selective 5-HT1B receptor agonist (CP 93,129). 5-HT-moduline tissue content in hippocampus from individual animals was determined by ELISA using a polyclonal anti-5-HT-moduline antibody. In moderately trained animals (n=5), the CP 93,129-stimulated [35S]GTPgammaS binding curve was shifted to the right compared with controls (n=6), whereas the binding was totally suppressed in intensely trained animals (n=5). In parallel, 5-HT-moduline tissue concentration in the hippocampus was slightly increased in moderately trained animals (117.3 +/- 8.9%) (n=5), whereas it was significantly increased in intensely trained animals (182.6 +/- 29.5%) (n=5) compared to controls (100 +/- 6.11%) (n=6). These results show that 5-HT1B receptors are slightly desensitized in moderately trained animals and totally desensitized in intensely trained animals; moreover, they suggest that the observed desensitization is related to an increase of 5-HT-moduline tissue content; this mechanism may play a role in various pathophysiological conditions.

Animals↗

PubMed2000

Energy expenditure of horse riding.

Oxygen consumption (VO2), ventilation (VE) and heart rate (HR) were studied in five recreational riders with a portable oxygen analyser (K2 Cosmed, Rome) telemetric system, during two different experimental riding sessions. The first one was a dressage session in which the rider successively rode four different horses at a walk, trot and canter. The second one was a jumping training session. Each rider rode two horses, one known and one unknown. The physiological parameters were measured during warm up at a canter in suspension and when jumping an isolated obstacle at a trot and canter. This session was concluded by a jumping course with 12 obstacles. The data show a progressive increase in VO2 during the dressage session from a mean value of 0.70 (0.18) l x min(-1) [mean (SD)] at a walk, to 1.47 (0.28) l x min(-1) at a trot, and 1.9 (0.3) l x min(-1) at a canter. During the jumping session, rider VO2 was 2 (0.33) l x min(-1) with a mean HR of 155 beats x min(-1) during canter in suspension, obstacle trot and obstacle canter. The jumping course significantly enhanced VO2 and HR up to mean values of 2.40 (0.35) l x min(-1) and 176 beats x min(-1), respectively. The comparison among horses and riders during the dressage session shows differences in energy expenditure according to the horse for the same rider and between riders. During the jumping session, there was no statistical difference between riders riding known and unknown horses. In conclusion these data confirm that riding induces a significant increase in energy expenditure. During jumping, a mean value of 75% VO2max was reached. Therefore, a good aerobic capacity seems to be a factor determining riding performance in competitions. Regular riding practice and additional physical training are recommended to enhance the physical fitness of competitive riders.

Adult↗

PubMed2000

Simultaneous NMR microdialysis study of brain glucose metabolism in relation to fasting or exercise in the rat.

To study the impact of exercise or fasting and of subsequent glucose supplementation on glucose metabolism in rats, a spectrophotometric method was used to determine peripheral blood glucose; a technique associating (1)H-NMR spectroscopy and cortical microdialysis was also used to observe intra- plus extracellular and extracellular brain glucose variations, respectively. Compared with control animals (204 +/- 19 microM in dialysate, n = 10), exercise increased brain extracellular glucose levels to 274 +/- 22 microM (n = 8; P < 0.05), whereas fasting induced a drop in glucose levels down to 140 +/- 9 microM (n = 8; P < 0.05). After fasting, glucose supplemented by infusion increased glycemia from 7.4 +/- 0.4 to 19.9 +/- 0.8 mM (n = 10; P < 0.001), as well as extracellular and extra- plus intracellular brain glucose to 263 +/- 20% (n = 8; P < 0.001) and 342 +/- 28% (n = 8; P < 0.001), respectively, over basal for that group. After exercise, a similar infusion increased glycemia from 7. 3 +/- 0.3 to 16.8 +/- 1.1 mM (n = 10; P < 0.001), as well as extracellular and extra- plus intracellular brain glucose to 178 +/- 19% (n = 8; P < 0.001) and 244 +/- 20% (n = 8; P < 0.001), respectively, over basal for that group. These results confirmed the existence of a link between glucose level variations in peripheral and cerebral areas but also showed that exercise increased extracellular brain glucose levels despite peripheral hypoglycemia, suggesting a specific regulation mechanism of cerebral glucose metabolism during exercise.

Animals↗

PubMed2000

Functional magnetic resonance imaging of mental strategy in a simulated aviation performance task.

BACKGROUND: The objective of this study was to analyze the sensory and cognitive functions associated with activated brain regions characterizing mental strategy relative to degree of expertise in aviation-related tasks. METHODS: We used echo-planar functional magnetic resonance imaging (fMRI) technique to examine brain activity in expert pilots (n = 6) compared with novice pilots (n = 6) during performance of a simulated aviation track-following task at 200 knots vs. 100 knots. RESULTS: Expert pilots showed reduced activity in visual and motor regions that contrasted with predominant activation within anterior structures including the frontal and prefrontal cortices; structures involved in visual working memory, planning, selective attention and decision making functions. Novice pilots showed widespread activation of anterior and posterior brain structures, with a rise in activity in the visual, parietal and motor cortices as task difficulty increased. CONCLUSIONS: A high level of performance in the track-following task related to a high degree of expertise in the aviation field. This corresponded to experts performing perceptual and mnemonic processing through a network of specialized functions from visual through multiple prefrontal areas. By contrast, the novice pilots predominantly show activity associated with non-specific perceptual processing and without subsequent representation of selective information in working memory.

Adult↗

PubMed1999

Effects of GABA-transaminase inhibition on brain metabolism and amino-acid compartmentation: an in vivo study by 2D 1H-NMR spectroscopy coupled with microdialysis.

The aim of this work was to study the neurochemical effects in the brain of GABA-transaminase inhibition by systemic administration of gabaculine (100 mg/kg, i.a.) in the rat. In order to investigate neurotransmitter and related amino-acid compartmentation and metabolism, we have developed an original tool: the coupling, in vivo, on the same animal, of 2D COSY 1H-NMR spectroscopy with intracerebral microdialysis. The main result is a continuous increase in GABA levels, both in the intracellular compartment (up to 3000+/-450%; P<0.001) and extracellular compartment (up to 808+/-82%; P<0.01) at the sixth hour. The intracellular increase in GABA level became significant at the first hour following gabaculine administration, whereas the extracellular level increased as of the second hour, probably indicating that accumulation of GABA in nerve endings precedes its release in synaptic clefts. Moreover, the levels of the excitatory amino acids, glutamate and aspartate, were decreased both in the intra- and extracellular compartments, thus enhancing sedative effects of the drug. We also observed a decrease in the global energetic creatine-phosphocreatine pool, which also could be related to the sedative properties of gabaculine, measurable by the diminution of cortical electrical activity and mean arterial blood pressure. Finally, the coupling between 2D 1H-NMR spectroscopy and intracerebral microdialysis appears to be an original tool for investigating the cerebral metabolic effects induced by pharmacological agents, in situ, in living animals.

4-Aminobutyrate Transaminase↗

PubMed1999

Effects of hindlimb suspension and androgen treatment on testosterone receptors in rat skeletal muscles.

This study tested the specific and combined effects of testosterone treatment and hindlimb suspension (HS) on the properties of steroid receptors in skeletal muscle. Male rats were either administered weekly high doses of testosterone heptylate (10 mg x kg(-1)) or olive oil placebo, and were either tail-suspended or acted as controls. After 3 weeks of treatment, three muscles were excised from each animal, soleus (SOL), extensor digitorum longus (EDL), and plantaris. The results showed that the testosterone treatment was unable to minimise the HS-induced atrophy of skeletal muscle. As expected, HS altered the fibre-type composition of SOL muscles (-33% of type I, +188% and +161% of type IIa and intermediate fibres respectively, P < 0.01). No overall effect of treatment was detected on the fibre-type composition of either slow or fast-twitch muscles. Binding capacity determined by a radiocompetition technique was increased by HS, especially in SOL and EDL muscles (P < 0.01), while HS or steroid treatment decreased the affinity of the steroid receptors. The combination of HS and testosterone administration resulted in a decrease in binding capacity and affinity of steroid receptors in skeletal muscles. Steroid receptors in fast-twitch muscles exhibited a higher affinity than those in slow-twitch muscles, and it is suggested that it is likely that testosterone treatment is more effective in fast-twitch than in slow-twitch muscles. It was concluded that the lack of preventive effect of testosterone treatment on HS-induced SOL muscle atrophy could be explained by both a decrease in steroid sensitivity and the removal of mechanical factors.

Adipose Tissue↗