Made available in DSpace on 2016-01-26T18:55:45Z (GMT). No. of bitstreams: 1 Dissertacao Fernando.pdf: 431045 bytes, checksum: 5ae1b35993c556c6871734dee523f3dc (MD5) Previous issue date: 2008-06-26 / Libido is an important component of a bull s breeding ability; however it is difficult to make as assessment of libido during a breeding soundness examination. It is best assessed in young bulls and scrotal circumference is favorably correlated with semen traits. Sixteen Brangus and eight Brown-Swiss bulls, with 36 months old, extensively managed were evaluated. The objective of this work is to study the relationship between scrotal circumference, libido, hormones and semen characteristics in Brangus and Brown-Swiss bulls. Bulls were divided into two experimental groups: group 1, with 16 bulls Brangus, and group 2, with 8 bulls Brown-Swiss, evaluated for sexual soundness using physical and morphological characteristics of semen, sexual behavior, testosterone and cortisol serum concentrations. There was a difference in the serum testosterone (P<0,05) and cortisol (P<0,01) concentrations between groups. No correlation (P>0,05) between libido, scrotal circumference, motility , concentration, testosterone and major defects were obtained. It was observed correlation among motility and mass movement (0,50; P<0,01), vigor and mass movement (0,58; P<0,01), libido and vigor (0,55; P<0,01), libido and cortisol (-0,41; P<0,05). In conclusion, were not correlations between libido and sperm quality, libido and scrotal circumference, libido and testosterone. / A libido é um importante componente da habilidade de procriação dos touros, todavia, não é fácil realizar a mensuração da mesma durante o exame do aparelho reprodutor. A libido é melhor traduzida em touros jovens e a circunferência escrotal está favoravelmente correlacionada com o perfil do sêmen. Dezesseis touros Brangus e oito Pardos-suiços, com 36 meses de idade, criados extensivamente, foram avaliados. O objetivo deste trabalho foi estudar as relações entre circunferência escrotal, libido, hormônios e características do sêmen em touros Brangus e Pardos-suiços. Os touros foram divididos em dois grupos experimentais: grupo 1, com 16 touros Brangus e grupo 2, com 8 touros Pardos-suiços, avaliados sexualmente por meio de exame físico e das características morfológicas do sêmen, comportamento sexual e concentrações séricas de testosterona e cortisol. Houve diferença nas concentrações séricas de testosterona (P>0,05) entre libido, circunferência escrotal, motilidade, concentração, testosterona e defeitos maiores foi obtida. Observou-se correlação entre motilidade e turbilhão (0,50: P<0,05), vigor e turbilhão (0,58: P<0,01), libido e vigor (0,55; p<0,01) e para libido e cortisol (-0,41; P<0,05). Conclui-se que não há correlações entre libido e qualidade espermática, libido e circunferência escrotal e entre libido e testosterona.

Made available in DSpace on 2016-07-18T17:53:06Z (GMT). No. of bitstreams: 1 dissertacao Luciana Alvares Calvo Penha.pdf: 262652 bytes, checksum: c5d5a66986ee73998c29be43156901d5 (MD5) Previous issue date: 2009-11-23 / This study evaluated the effect of probiotic supplementation on both weight gain and serum cortisol concentration in cattle. Forty Nelore calves around 18 months old were randomly assigned to one of two groups (N=20 calves each) which received only mineral mixture (GC) or mineral mixture supplemented with 4.0 g probiotic Proenzime® per animal per day (GP). The cattle were subjected to handling stress by the usual weighing practices in the corral as well as blood sampling on days 0, 75 and 150. Live weight gain increased in GP (8.20 Kg; 17.07%) from day 0 to 75 (P<0.05); no weight differences were detected from day 76 to 150 (P>0.05). Cortisol concentration increased in GC cattle on day 150 (P<0.05). In GP cattle serum cortisol was constant over the experiment (P>0.05). On day 150, cortisol concentration were higher in GC as compared to GP. No correlations were detected between live weight gain and serum cortisol on days 75 (r= -0.005ns) and 150 (r= -0.007ns). These results indicate that: probiotic administration enhances weight gain in cattle for 75 days but not longer; and day 150 probiotic supplementation can lower cortisol concentration in cattle that are frequently stressed by handling and weighing practices in the corral. / Este estudo avaliou o efeito da suplementação com probiótico no cortisol sérico e no ganho de peso em bovinos. Quarenta bezerros Nelore com cerca de 18 meses de idade foram distribuídos aleatoriamente para um dos dois grupos (N = 20 bezerros cada) que receberam apenas mistura mineral (GC) ou mistura mineral suplementado com 4,0g de probiótico Proenzime® (GP) por animal por dia. Os bovinos foram submetidos ao estresse pela prática da manipulação habitual de pesagem no curral, bem como amostragem sangue nos dias 0, 75 e 150. O ganho de peso vivo aumentou no GP (8,20 kg; 17,07%) do dia 0 aos 75 (P < 0,05) e no ganho de peso não foram detectadas diferenças a partir do dia 76 a 150 (P > 0,05). A concentração do cortisol aumentou nos bovinos do GC no dia 150 (P < 0,05) e nos bovinos do GP o cortisol sérico foi constante ao longo do experimento (P > 0,05). No dia 150 as concentrações de cortisol foram maiores no GC em comparação com o GP. Não foram detectadas correlações entre ganho de peso vivo e cortisol sérico nos dias 75 (r =-0.005ns) e 150 (r =-0.007ns). Estes resultados indicam que a administração de probiótico aumentou o peso nos bovinos nos primeiros 75 dias, e no dia 150 a suplementação diminuiu a concentração sérica de cortisol do qual se encontram freqüentemente submetidos a movimentação e a prática da pesagem no curral.

Made available in DSpace on 2016-07-18T17:53:08Z (GMT). No. of bitstreams: 1 Dissertacao.pdf: 371163 bytes, checksum: 00d67c3200895b27fd357306527c561c (MD5) Previous issue date: 2011-03-18 / The objective of this work was to study the seasons influence (spring, summer, autumn and winter) on semen characteristics and hormones (testosterone and cortisol) in Nelore and Simental bulls. Five Nelore and five Simental bulls were 48-72 months old, extensively managed, were evaluated for sexual soundness using physical and morphological characteristics of semen and hormonal serum levels. There was decreased motility and vigor semen (P<0.05) during winter in Simental bulls. There was correlation between serum testosterone and cortisol (P<0.01) to motility and vigor in either Nelore and Simental bulls. In conclusion, these results showed a hormonal and semen characteristics variation throughout the season change the semen quality. Bulls from Nelore breed differed from Simental, demonstrating adaptability to the field conditions. / O objetivo desse trabalho foi estudar a influência das quatro estações do ano: (primavera, verão, outono e inverno), nas características do sêmen e nos níveis de testosterona e cortisol em touros Nelore e Simental. Cinco touros Nelore e cinco Simental com 48-72 meses de idade, criados extensivamente, foram avaliados andrologicamente por meio de exame físico e das características morfológicas do sêmen, concentrações séricas de testosterona e cortisol. Houve queda na motilidade e vigor do sêmen no inverno (p<0,05) para a raça Simental. Houve correlação entre a concentração sérica de testosterona e cortisol (P<0,01) para a motilidade e vigor espermático para os touros Nelore e Simental. Conclui-se que houve variação hormonal e nas características do sêmen ao longo das estações modificando a qualidade do sêmen. Os touros da raça Nelore diferiram dos da raça Simental, demonstrando adaptabilidade às condições do campo.

Made available in DSpace on 2016-07-18T17:53:18Z (GMT). No. of bitstreams: 1 Dissertacao Fernando.pdf: 431045 bytes, checksum: 5ae1b35993c556c6871734dee523f3dc (MD5) Previous issue date: 2008-06-26 / Libido is an important component of a bull s breeding ability; however it is difficult to make as assessment of libido during a breeding soundness examination. It is best assessed in young bulls and scrotal circumference is favorably correlated with semen traits. Sixteen Brangus and eight Brown-Swiss bulls, with 36 months old, extensively managed were evaluated. The objective of this work is to study the relationship between scrotal circumference, libido, hormones and semen characteristics in Brangus and Brown-Swiss bulls. Bulls were divided into two experimental groups: group 1, with 16 bulls Brangus, and group 2, with 8 bulls Brown-Swiss, evaluated for sexual soundness using physical and morphological characteristics of semen, sexual behavior, testosterone and cortisol serum concentrations. There was a difference in the serum testosterone (P<0,05) and cortisol (P<0,01) concentrations between groups. No correlation (P>0,05) between libido, scrotal circumference, motility , concentration, testosterone and major defects were obtained. It was observed correlation among motility and mass movement (0,50; P<0,01), vigor and mass movement (0,58; P<0,01), libido and vigor (0,55; P<0,01), libido and cortisol (-0,41; P<0,05). In conclusion, were not correlations between libido and sperm quality, libido and scrotal circumference, libido and testosterone. / A libido é um importante componente da habilidade de procriação dos touros, todavia, não é fácil realizar a mensuração da mesma durante o exame do aparelho reprodutor. A libido é melhor traduzida em touros jovens e a circunferência escrotal está favoravelmente correlacionada com o perfil do sêmen. Dezesseis touros Brangus e oito Pardos-suiços, com 36 meses de idade, criados extensivamente, foram avaliados. O objetivo deste trabalho foi estudar as relações entre circunferência escrotal, libido, hormônios e características do sêmen em touros Brangus e Pardos-suiços. Os touros foram divididos em dois grupos experimentais: grupo 1, com 16 touros Brangus e grupo 2, com 8 touros Pardos-suiços, avaliados sexualmente por meio de exame físico e das características morfológicas do sêmen, comportamento sexual e concentrações séricas de testosterona e cortisol. Houve diferença nas concentrações séricas de testosterona (P>0,05) entre libido, circunferência escrotal, motilidade, concentração, testosterona e defeitos maiores foi obtida. Observou-se correlação entre motilidade e turbilhão (0,50: P<0,05), vigor e turbilhão (0,58: P<0,01), libido e vigor (0,55; p<0,01) e para libido e cortisol (-0,41; P<0,05). Conclui-se que não há correlações entre libido e qualidade espermática, libido e circunferência escrotal e entre libido e testosterona.

No description available.

Background: Studies with experimental administration of alcohol offer inconsistent approaches and interpretations in which ways an acute alcohol exposure affects the HPA-system and the cortisol secretion. So far published alcohol experiments differ in alcohol application, the possibility of alcohol self-administration at the subjects own discretion as well as the age of the participants. Question: Is cortisol secretion modified by gender during alcohol infusion? Do men and women show different cortisol levels under alcohol exposure when compared to the baseline? Is there a dose-response relationship between cortisol secretion and acute alcohol exposure? Have family history, smoking habits and alcohol induced side effects like nausea an influence on the cortisol secretion under alcohol exposure? Materials and methods: 48 18 year old subjects participated in two identical sessions in which they were able to regulate their maximum blood alcohol concentration up to a safety limit of 1.2 ‰ (i.e., 0.12%). The experiment was conducted by using a special software for self-infusion of ethanol (CASE) which guided the participants through a two and a half hours long experiment. CASE is founded on a validated physiologically-based pharmacokinetic model and involves calculating the infusion volume needed to increase the blood alcohol concentration in a linear manner. The BAC increases after each alcohol request by 0,075 ‰ (i.e., 0.0075%) within in two and a half minutes. If the subject infuses no alcohol the blood alcohol concentration will decrease by 0.01 ‰ (i.e., 0.001%) per minute. Through the precise calculation of the infusion rate, individual differences can be eliminated. Cortisol levels were measured at five time points: an initial baseline measurement and four measurements at fixed time points during the alcohol self-administration of subjects with two completed alcohol experiments. As an appropriate measure to examine the effect of alcohol self-administration on cortisol secretion, the maximum blood alcohol concentration was determined. In addition the day of experiment, gender and family history were observed as well as exploratory maximum nausea and smoking habits. Results: In conclusion, the results confirmed that women have higher cortisol levels than men at baseline and under alcohol influence. Blood alcohol concentration as examined influencing variable was shown to have different effects on the HPA system on day one and two. On the first day of experimentation there was no effect of blood alcohol concentration on the HPA system. On the second day a dose-response relationship could be identified between cortisol secretion and acute alcohol exposure. Individually higher blood alcohol concentrations attenuated cortisol stronger in comparison to subjects with lower blood alcohol concentrations. Family history, smoking habits and unpleasant side effects (nausea) did not affect the cortisol secretion under alcohol exposure in this series of experiments. Conclusions: Current data suggests that alcohol experiments affect the cortisol secretion in young social drinkers. These findings could be detected for the first time. Up to this point there has not been an experimental study that investigated and evaluated the dose-effect relationship between cortisol secretion and alcohol in a study design which uses intravenous alcohol self-administration. It can be theorized that the first day of experimentation is suitable as a settling-in phase due to unspecific confounding factors, whereas the second day can be considered, in an identical setting, apt for hypothesis testing. The increased cortisol level in women when compared to men is consistent with previous studies and there was no indication that family history, smoking habits and alcohol induced unpleasant side effects have an influence on cortisol secretion.:Inhaltsverzeichnis 3 Abbildungsverzeichnis 6 Tabellenverzeichnis 7 Abkürzungsverzeichnis 8 1 Einleitung 10 1.1 Alkohol – eine kurze Einführung 10 1.2 Bedeutung des Zusammenhangs von HPA-System und Alkohol 12 1.2.1 Experimentelle Alkoholselbstverabreichung 12 1.2.2 Neuropharmakologie von Alkohol 13 1.2.3 Geschlechtsunterschiede bei der Cortisolsekretion 14 1.2.4 Übelkeit und die Auswirkungen auf die Cortisolsekretion unter Alkoholexposition 15 1.3 Orale Alkoholverabreichung versus intravenöse Alkoholverabreichung 16 1.4 Zielsetzung 19 2 Material und Methoden 20 2.1 Versuchsteilnehmer 20 2.1.1 Einschlusskriterien 20 2.1.2 Ausschlusskriterien 21 2.1.3 Aufnahmeuntersuchung 22 2.2 Versuchsaufbau und Durchführung 22 2.2.1 Versuchsprinzip 23 2.2.2 Versuchsablauf 24 2.2.3 Verwendete Materialien 27 2.2.4 CASE Software 27 2.2.5 Herstellung der 6%igen Alkohol-Infusionslösung 29 2.2.6 Messung der BAK 30 2.2.7 Verwendete Fragebögen und Selbsteinschätzungstests 30 2.3 Blutverarbeitung 31 2.3.1 Blutbehandlung im Labor (Testkit der Firma IBL International GMBH) 32 2.3.1.1 Testprinzip im Labor 32 2.3.1.2 Testdurchführung bei Serumproben 32 2.3.1.3 Testauswertung 33 2.4 Statistische Auswertung 33 3 Ergebnisse 37 3.1 Versuchsteilnehmer 37 3.2 Konfirmatorische Datenanalyse der Cortisolsekretion 38 3.2.1 CASE Ergebnisvariablen 38 3.2.2 Analyse von Baseline Cortisol Tag eins vs. Tag zwei 39 3.2.3 Einfluss von Familienanamnese, Geschlecht und maximalem Blutalkohol auf die Cortisolsekretion 40 3.2.3.1 Beobachtung beider Experimentaltage zusammen 40 3.2.3.2 Getrennte Beobachtung für den ersten Experimentaltag 44 3.2.3.3 Getrennte Beobachtung für den zweiten Experimentaltag 46 3.2.3.4 Einfluss von max BAK Tag zwei auf den prozentualen Anteil der Nettofläche an der Gesamtfläche Tag zwei 48 Explorative Analyse von potentiellen weiteren Einflussfaktoren 49 3.3.1 Der Effekt von Übelkeit auf die Cortisolsekretion 49 3.3.2 Der Effekt von Rauchen auf die Cortisolsekretion 50 4 Diskussion 52 4.1 Auswahl der CASE Ergebnisvariablen 52 4.2 Unterschiede zwischen dem ersten und zweiten Experimentaltag 53 4.3 Verschiedene Einflüsse auf die Cortisolsekretion 54 4.3.1 Einfluss von Geschlecht 54 4.3.2 Einfluss von max BAK 55 4.3.3 Einfluss von Familienanamnese 55 4.4 Unterschiede zu vorhergehenden Studien 56 4.5 Diskussion der explorativen Datenanalyse 57 4.5.1 Einfluss von Übelkeit auf die Cortisolsekretion 57 4.5.2 Einfluss von Rauchen auf die Cortisolsekretion 58 4.6 Limitation der D-LAYA Studie 59 4.7 Ausblick 60 Zusammenfassung 61

In dieser Arbeit wurde die Reaktivität der Hypothalamus-Hypophysen-Nebennieren-Achse (HHN-Achse) vergleichend zwischen Panikstörung (mit/ohne Agoraphobie) und Posttraumatischer Belastungsstörung (PTBS) gegenüber einer gesunden Kontrollgruppe anhand eines validierten Stresstests, dem Trier-Sozial-Stress-Test (TSST), untersucht. Es wurde die bestehende Theorie einer eingeschränkten HHN-Achsen-Reaktion bei akutem psychosozialen Stress bei Panikstörung und PTBS bestätigt. Zusätzlich konnten erstmalig beide Patientengruppen direkt miteinander verglichen und der Einfluss u.a. einer komorbiden Depression untersucht werden. Es wurden 90 Frauen zwischen 18 bis 65 Jahren in diese Studie eingeschlossen. Die Diagnose der Panikstörung sowie der PTBS gemäß ICD-10 erfolgte anhand des SKID-I. Ausgeschlossen wurden Probanden mit psychotischen, bipolaren, generalisierten Angst- und Persönlichkeitsstörungen und unter Therapie mit cortisonhaltigen Medikamenten, Insulin, Betablockern oder bei Zustand nach Chemotherapie. In der Gruppe Panikstörung (N = 28, 39.8 Jahre) hatten 15 Frauen und in der Gruppe PTBS (N = 28, 41.4 Jahre) 23 Frauen eine komorbide depressive Störung und 7 Frauen eine zusätzliche Panikstörung. Der TSST wurde nachmittags von 14 bis 17 Uhr durchgeführt. Gemessen wurde der Verlauf von Cortisol im Serum und Speichel sowie ACTH im Serum (2x vor und 6x nach dem TSST) sowie Varianzanalysen mit Messwiederholung und Vergleich der Integrale „area unter the curve with respect to the ground/to increase“ durchgeführt. Die gesunde Kontrollgruppe (N = 28, 38.4 Jahre) zeigte einen regelhaften ACTH- und Cortisolanstieg und –abfall. Ausgehend von gleichen Baselinewerten stellten sich die Hormonreaktionen der Patientengruppen signifikant schwächer dar. Die Stärke der Hormonreaktion beider Patientengruppen war annähernd gleich. Die vier Kovariaten Raucherstatus, Zyklusstatus, BMI und die Depressionsschwere zeigten keinen beachtlichen Einfluss. In der Subgruppenanalyse schien die Gruppe PTBS mit komorbider Panikstörung eine schwächere ACTH-Reaktion als die Gruppe mit reiner PTBS zu haben (gleiche Cortisolreaktion). Die Subgruppen mit komorbider Depression wiesen die schwächsten ACTH-Reaktionen auf und die Cortisolantwort der Gruppe PTBS mit Depression fiel am geringsten aus (Panikstörung mit/ohne Depression gleich). Es ergaben sich keine signifikanten Korrelationen zwischen der Cortisolreaktion und Merkmalen der parallel erhobenen Fragebögen (SCL-90-R, PAS, BDI, PSS, PASA, STAI etc.). Die Kategorisierung von Non- und Respondern muss in weiteren Studien geprüft werden, da neben unterschiedlichen Grenzwerten in der Literatur die Probanden beachtet werden müssen, die im Testverlauf stetig abfallende Hormonspiegel hatten.

De nombreuses études suggèrent que la maltraitance à l’enfance est un facteur de risque important lié à l’émergence de symptômes dépressifs à l’âge adulte. Toutefois, les mécanismes biologiques qui sous-tendent cette association demeurent méconnus. Ainsi, cette étude vise à examiner le rôle de la méthylation de l’ADN et de la réactivité au stress dans l’association entre les expériences de maltraitance à l’enfance et les symptômes dépressifs à l’âge adulte. L’échantillon est composé de 156 hommes âgés entre 18 et 35 ans. Les expériences de maltraitance et les symptômes dépressifs ont été mesurés à l’aide de questionnaires auto- rapportés. La sécrétion de cortisol, une hormone sécrétée en situation de stress, a été mesurée en réponse au Trier Social Stress Test. La méthylation de l’ADN de neufs gènes candidats (COMT, FKBP5, IL-6, IL-10, MAOA, NR3C1, OXTR, SLC6A3 et SLC6A4) a été quantifiée à l’aide du système Sequenom EpiTYPER suite à l’extraction de l’ADN salivaire. Les résultats indiquent que la méthylation de l’ADN n’explique pas l’association entre les expériences de maltraitance à l’enfance et les symptômes dépressifs à l’âge adulte et les associations sous-jacentes à l’effet indirect de la méthylation de l’ADN ne varient pas en fonction de la réactivité cortisolaire au stress. Néanmoins, les résultats de l’étude suggèrent que les expériences de maltraitance et les symptômes dépressifs sont associées à des changements dans les profils de méthylation de l’ADN. Enfin, ces résultats soulignent l’importance de réduire la prévalence de la maltraitance à l’enfance afin de limiter l’apparition de symptômes dépressifs à l’âge adulte. / Increasing evidence suggests that child maltreatment is a significant risk factor for the emergence of depressive symptoms in adulthood. However, the mechanisms underlying this association remain poorly understood. The present study examined the mediating role of DNA methylation and the moderating role of stress reactivity in the association between child maltreatment and depressive symptoms in emerging adulthood. The sample comprised 156 young male adults aged between 18 and 35 years. Maltreatment experiences and depressive symptoms were assessed using self-reported questionnaires. Cortisol, a hormone secreted in response to stress, was measured in response to the Trier Social Stress Test. DNA methylation of nine candidate genes (COMT, FKBP5, IL-6, IL-10, MAOA, NR3C1, OXTR, SLC6A3 et SLC6A4) was quantified using the Sequenom EpiTYPER technology after the extraction of salivary DNA. Results suggest that DNA methylation did not explain the association between child maltreatment and depressive symptoms in emerging adulthood, and that the associations underlying the mediating effect of DNA methylation did not vary according to the cortisol stress response. Nonetheless, the results suggest that maltreatment experiences and depressive symptoms are both associated with changes in DNA methylation profiles. Finally, these findings underscore the importance of reducing the prevalence of child maltreatment in order to limit the onset of depressive symptoms in emerging adulthood.

Hintergrund: Diese doppelblinde, randomisierte und kontrollierte Studie untersucht den Effekt von instrumentaler Musik auf Stresshormone und den Verbrauch von Sedativa während einer in Spinalanästhesie durchgeführten elektiven Hüftprothesenoperation. Methoden: 40 Patienten wurden entweder einer Musikgruppe oder einer Kontrollgruppe zugeteilt. Beiden Gruppen wurde die Musik beziehungsweise der Kontrollstimulus circa zwei Stunden vor und während der gesamten Operation dargeboten. Ergebnisse: Patienten der Musikgruppe hatten einen geringeren Sedativaverbrauch und geringere Cortisolwerte als Patienten der Kontrollgruppe. Schlussfolgerung: Die Ergebnisse dieser Studie zeigen, dass Musik während einer Operation in Spinalanästhesie den Sedativaverbrauch senken und zur Verringerung des Stressniveaus gemessen an den Cortisolwerten beitragen kann. Der Einsatz von Musik in bestimmten klinischen Situationen zur Stressreduktion erscheint deshalb sinnvoll.

La restriction des apports alimentaires est une méthode couramment utilisée pour perdre du poids dans les sports à catégories de poids. La réduction des apports caloriques se traduit par une activation des systèmes physiologiques du stress, au niveau central et périphérique, visant à préserver l’homéostasie énergétique. Néanmoins, l’influence sur les paramètres physiologiques, psychologiques et physiques reste controversée et ne permet pas de définir clairement un impact négatif de la restriction alimentaire sur la santé et le niveau de performance. L’objectif de ce travail était d’évaluer l’influence d’une restriction alimentaire sur les indicateurs psychophysiologiques du stress, ainsi que le niveau de performance chez des haltérophiles de haut niveau. Nos résultats ont montré que la restriction alimentaire ne modifiait pas le niveau de performance en haltérophilie, mais induisait une altération des paramètres psychologiques. La période de restriction alimentaire se traduisait par une dissociation de l’activité des systèmes physiologiques du stress, ainsi qu’une modification des réponses hormonales à une compétition simulée d’haltérophilie. Il reste à définir les répercussions à long terme de l’altération des paramètres psychophysiologiques sur la santé et la capacité de performance du sportif. Il serait également intéressant d'étudier l'influence de la restriction alimentaire sur le microbiote intestinal et les répercussions éventuelles sur l'axe intestin-cerveau. / Restricting dietary intake is a widespread method for losing weight in weight categories sports. Reduction of calorie intake results in an activation of the physiological stress systems, both at central and peripheral levels, aiming at preserving energy homeostasis. Nevertheless, the influence on physiological, psychological and physical parameters remains controversial and do not allows to clearly defining a negative impact of dietary restriction on health and performance level. The objective of this study was to evaluate the influence of a dietary restriction period on the psychophysiological indicators of stress, as well as the level of performance in high-level weightlifters. Our results showed that dietary restriction did not modify weightlifting performance level, but resulted in an alteration of the psychological parameters. The dietary restriction period resulted in a dissociation of the activity of the physiological stress systems, as well as a modification of the hormonal responses to a simulated weightlifting competition. It remains to define the long-term impacts of the alteration of psychophysiological parameters on the athlete’s health and performance capacity. It would also be interesting to evaluate the influence of dietary restriction on intestinal microbiota and the possible influence on the gut-brain axis.