Nós investigamos o efeito sequencial do treinamento aerório (T) nas vias ocitocinérgicas (OTérgicas) em áreas centrais autonômicas, utilizando o fator neurotrófico derivado do cérebro (BDNF) como um indicador de plasticidade neuronal. Ratos normotensos (WKY) e espontaneamente hipertensos (SHR) foram submetidos a T ou sedentarismo (S) por 8 semanas. T causou bradicardia de repouso (SHR=T2-T8; WKY=T8) e redução da PA (SHR=T8). T promoveu aumento precoce (T1) da expressão de BDNF, sendo em WKY aumento transiente e SHR mantido. A irBDNF foi similarmente aumentado em WKY e SHR de T1-T2 até T8. Tais alterações foram acompanhadas por aumento no conteúdo de OT nas áreas biossintéticas e de OTR nas áreas de projeção. Os resultados indicam que a plasticidade induzida pelo T no sistema OTérgico central ocorre precocemente no PVN comparado com outras áreas autonômicas, é mais rápido em WKY e precede as mudanças da FC. Os dados também mostram maior \"turnover\" do RNAm de BDNF no grupo SHR. / We investigate time-course training (T) effects on oxitocinergic (OTergic) pathways within autonomic areas, using brain-derived neurotrophic factor (BDNF) as a index of neuronal plasticity. Normotensive (WKY) and spontaneously hypertensive rats (SHR) were submitted to low-intensity T or sedentarism (S) for 8 weeks. T caused resting bradycardia (SHR=T2-T8; WKY=T8) and reduced AP (SHR=T8). T induced precocious increase (T1) of BDNF expression, with transient increase in WKY and sustained in SHR. BDNFir was similarly increased in WKY and SHR (T1-T2 until T8). These changes were accompanied by increased content of OT in biosynthetic areas and OTR in projection areas. Results indicate that T-induced plasticity of central OTergic system occurs precociously in the PVN compared to other autonomic areas, is faster in WKY and precedes HR changes. Data also showed higher BDNF mRNA turnover in the SHR group.

A ocitocina (OT) é um neuropeptídio hipotalâmico, que dentre suas funções na fêmea destaca-se a contração uterina durante o parto e a ejeção do leite. No entanto, estudos vêm demonstrando importantes funções endócrinas e parácrinas no trato reprodutivo masculino. Evidenciando a possível ação conjunta entre OT e a Globulina ligadora de hormônios sexuais (SHBG). Entretanto, em cães não existem informações disponíveis quanto sua atuação. Assim, estudos direcionados aos receptores de ocitocina (OTR) e SHBG e suas funções no sistema reprodutor masculino, mais especificamente na fisiologia espermática, são de suma importância para os conhecimentos da fisiologia reprodutiva para posterior aplicação em biotecnologias reprodutivas em pequenos animais e humanos, fomentando também novas perspectivas para a utilização terapêutica da ocitocina em enfermidades reprodutivas. Portanto, o objetivo deste estudo é verificar a expressão gênica e proteica do OTR e SHBG no testículo e epidídimo de cães, correlacionando tais dados com a qualidade espermática e dosagem de testosterona. Para tal, foram coletados testículos e epidídimos de 26 cães em idade reprodutiva (1 a 5 anos). Após a orquiectomia, foi realizada a coleta dos espermatozoides provenientes da cauda do epidídimo e então, as amostras foram analisadas quanto à motilidade computadorizada do sêmen (CASA), integridade de membrana plasmática (Eosina/Nigrosina), integridade de membrana acrossomal (Fast Green / Rosa Bengala) e atividade mitocondrial (3´3 Diaminobenzidine). A imunolocalização do OTR e SHBG foi realizada através de imunoistoquímica e imunofluorescência. E a análise de expressão gênica, através da Reação em cadeia da polimerase em tempo real (qRT PCR). E da expressão proteica, através do Western Blotting. Foram encontradas correlações significantes e positivas entre as expressões gênicas do OTR e do SHBG, tanto no testículo como no epidídimo. Além disto, a expressão do OTR no testículo correlacionou-se positivamente com espermatozoides com membrana acrossomal íntegra e negativamente com a porcentagem de células com baixa atividade mitocondrial. Já o SHBG do testículo, correlacionou-se positivamente com a concentração de espermatozoides, porcentagens de células com membrana plasmática e acrossomal íntegras, motilidade, motilidade progressiva e velocidade rápida, e negativamente com a porcentagem de células com baixa atividade mitocondrial. Por outro lado, no epidídimo, a expressão gênica do SHBG apresentou correlação positiva com a porcentagem de células com membrana plasmática íntegra e expressão proteica de SHBG no testículo. Quanto a expressão proteica, o OTR no testículo obteve correlação positiva com testosterona e negativa com atividade mitocondrial nula, já no epidídimo, ocorreu correlação positiva com integridade de membrana acrossomal e negativa também com atividade mitocondrial nula. Em relação ao SHBG, houve correlação positiva com a expressão gênica do SHBG no epidídimo, células normais e padrões de velocidade. E na imunoistoquímica foi possível observar a imunomarcação do OTR e SHBG na musculatura lisa e células de Leydig do testículo e OTR na musculatura lisa do epidídimo. No entanto, não houve imunomarcação do SHBG no epidídimo, assim como expressão proteica. Nossos resultados demonstraram que o OTR e SHBG são expressos nos testículos e epidídimos de cães e que estão relacionados a funções espermáticas importantes, sendo essenciais para o sucesso reprodutivo / Oxytocin (OT) is a hypothalamic neuropeptide that plays important and well known roles in the female such as uterine contraction during childbirth and milk ejection. Notwithstanding, studies have shown important endocrine and paracrine functions also in the male reproductive tract, highlighted by the possible joint action between OT and sex hormone-binding globulin (SHBG). In dogs, however, there is no information available with regards to the role of these hormones in the reproductive function. Thus, studies directed to oxytocin (OTR) and SHBG receptors and their functions in the male reproductive system, specifically with regards to sperm physiology. Such knowledge is essential to understand the reproductive physiology for the subsequent use in reproductive biotechnologies in small animals and humans, especially by providing new perspectives for the therapeutic use of oxytocin in reproductive disorders. Therefore, the aim of this study is to assess the gene and protein expression of OTR and SHBG in the testis and epididymis of dogs, correlating these data with sperm quality and testosterone dosage. To this end, testis and epididymis were collected from 26 dogs in reproductive age (1 to 5 years). After orchiectomy, collection of sperm from the cauda epididymis was carried out and then the samples were analyzed for computerized motility of semen (CASA), plasma membrane integrity (eosin / nigrosine), acrosome membrane integrity (Fast Green / rose Bengal) and mitochondrial activity (3\'3 Diaminobenzidine). The immunolocalization of OTR and SHBG was performed by immunohistochemistry and immunofluorescence. Gene expression analysis was performed by real time polymerase chain reaction (qRT - PCR). The protein expression was further assessed by Western Blotting. Significant positive correlations were found between the gene expressions of OTR and SHBG in both the testis and epididymis. Furthermore, the OTR expression in testis was positively correlated to sperm with intact acrosome membrane and negatively to the percentage of cells with low mitochondrial activity. On the other hand, testicular SHBG was positively correlated with sperm concentration, percentage of sperm with intact plasma membrane and acrosome, motility, progressive motility and the percentage of RAPID sperm. Also, negative correlation was found between testicular SHBG and the percentage of cells with low mitochondrial activity. Furthermore, in the epididymis, SHBG gene expression was positively correlated to the percentage of cells with intact plasma membrane and protein expression of SHBG in the testis. In relation to the protein expression, the OTR in the testis correlated positively with blood plasma testosterone and negatively with sperm with no mitochondrial activity. In the epididymis, OTR protein expression correlated positively with sperm showing intact acrosome and negatively with cells with no mitochondrial activity. With regards to SHBG proteins expression, there was a positive correlation to SHBG gene expression in the epididymis, normal cells and some patterns of sperm velocity. In the immunohistochemistry, we observed the OTR and SHBG immunostainings in the smooth muscle and Leydig cells of the testis while, in the epididymis, the OTR immunostaining could be observed only in the smooth muscle. Interestingly, there was no immunostaining or protein expression of SHBG in the epididymis. Our results demonstrated that OTR and SHBG are expressed in the testis and epididymis of dogs and are related to important sperm functions, essential for reproductive success

Em Medicina Veterinária, os avanços em Neonatologia são escassos quando comparados aos da Medicina Humana. Dentre as possíveis causas para esta situação atual destacam-se as particularidades fisiológicas deste período. Os objetivos do presente estudo foram: estabelecer os valores normais de algumas variáveis laboratoriais de neonatos nascidos de parto eutócico, identificar eventuais alterações metabólicas maternas e dos neonatos nascidos em diferentes condições obstétricas, verificar os efeitos da administração de ocitocina sob variáveis neonatais e maternas e mensurar os níveis de cortisol materno e neonatal como forma de estudar as diferentes situações de estresse no momento do parto. Vinte e nove fêmeas caninas foram alocadas em 3 grupos, de acordo com o tipo de parto: eutocia (grupo 1), distocia corrigida por manobras obstétricas ou cesariana (grupo 2) e indução de contrações uterinas com ocitocina (grupo 3). Cinqüenta e um neonatos foram avaliados por meio do sistema Apgar e temperatura corpórea ao nascimento, 5 minutos e 1 hora após o nascimento, bem como por avaliação hemogasométrica, dosagem de cortisol e glicemia ao nascimento e após 1 hora. A avaliação materna constituiu no controle da pressão arterial, monitorização cardíaca, glicemia e dosagem de cortisol em momentos pontuais no pré, intra e pós-parto. Os neonatos dos distintos grupos apresentaram acidose mista associada à hipóxia ao nascimento, com maior comprometimento metabólico nos filhotes do grupo 3. Após 1 hora, recuperaram-se do componente respiratório, mantendo apenas o quadro de acidose metabólica por maior comprometimento da hipóxia. A avaliação neonatal pelo escore Apgar demonstrou que filhotes do grupo 2 nascem em maior depressão que neonatos dos grupos 1 e 3, porém todos apresentam adequada recuperação após 1 hora. Nas parturientes, a administração de ocitocina favoreceu a elevação da pressão arterial para níveis normais durante o trabalho de parto, bem como o aumento da glicemia. Neonatos nascidos por manobra obstétrica ou cesariana apresentaram maior concentração de cortisol plasmático ao nascimento, em comparação aos grupos 1 e 3. Contudo, todos os neonatos apresentaram redução significativa dos níveis de cortisol após 1 hora do nascimento. Por outro lado, foi possível verificar maior concentração sérica deste hormônio após o término do parto nas fêmeas submetidas à infusão de ocitocina. Em conclusão, a administração de ocitocina é responsável por maiores alterações metabólicas em neonatos; na parturiente, a administração de ocitocina promove alterações na pressão arterial, glicemia e aumento da liberação de cortisol; a manobra obstétrica ou cesariana promove maior estresse neonatal ao nascimento. / Studies accomplishing canine neonatology are scarce in Veterinary Medicine comparing to Human Neonatology due to the particularity of this refered period. The aims of the present study were to establish standard laboratorial values of the canine neonate, identify metabolic changes of bitches and neonates born under different obstetric conditionsl, verify the consequences of dystocia treated medically by oxytocin administration on maternal and neonatal variables and to measure maternal and neonatal cortisol levels on distinc stress situations during parturition. Twenty nine canine females were allocated into 3 groups according to the obstetric conditions: eutocia (group 1; n=10), manipulative obstetric assistance or cesarean section (group 2; n=10) and maternal dystocia treated with oxytocin (group 3; n=9). Fifty one neonates were submitted to a clinical evaluation by Apgar scoring and body temperature measurement immediately after birth, at 5 and 60 minutes postnatal; and hemogasometric evaluation, blood glucose and cortisol assay immediately after birth and 60 minutes postnatal. Maternal noninvasive arterial blood pressure, blood glucose and cardiac monitoring were peformed during the first stage of labor, intra-partum, immediately after the last puppy was born and 1 hour later. Neonates from distinct groups showed mixed acidosis in addition to hypoxemia at birth. Neonates remained under metabolic acidosis even after 1 hour of birth due to a detrimental effect on hypoxia. Comparing the results among groups, puppies from group 2 showed significantly lower Apgar score at birth. However, 1 hour later all neonates showed full recovery. Dams subjected to oxytocin infusion showed an increase in blood pressure, hence switching to a normotension status and also presented higher glucose level during parturition. Manipulative obstetric assistance or cesarean section arised neonatal cortisol levels at birth. However, all neonates exhibited significantly lower cortisol concentration after 1 hour of birth. Bitches of group 3 showed significantly higher cortisol level immediatly after whelping. In conclusion, dystocia treated medically by oxytocin infusion resulted in more intense metabolic alterations compared to neonates born under eutocia; oxytocin administration promotes blood pressure enhance, glucose alterations and increase in maternal stress; manipulative obstetric assistance or cesarean section increased neonatal cortisol release at birth.

O sistema endocanabinóide (eCB) tem sido reconhecido como um importante modulador da homeostase energética e recentemente estudos o apontam como um possível integrador da homeostase hidroeletrolítica. Estudos recentes do nosso laboratório demonstraram a participação do receptor canabinóide do tipo 1 (CB1R) no controle da secreção neurohipofisária em resposta a expansão hipertônica do volume extracelular. Dessa forma, o presente trabalho visou esclarecer a participação do sistema eCB, particularmente do CB1R, nas respostas neuronais, neuroendócrinas e comportamentais induzidas pela sobrecarga salina de 4 dias (SS). Uma vez que os animais em SS apresentam hipofagia induzida pela hiperosmolalidade, buscou-se avaliar as vias de integração do controle da homeostase energética e do balanço hidroeletrolítico por meio da introdução de um grupo em dieta pareada (pair fed, PF). De forma a investigar a hipótese acima, utilizou-se como ferramenta farmacológica o agonista seletivo CB1R, araquidonil-2-cloroetilamida (ACEA - 0,1g/5L), administrado por via intracerebroventricular (icv). Inicialmente, nosso trabalho mostrou que a SS promoveu aumento da expressão de CB1R tanto nos núcleos supra-óptico (NSO) e paraventricular (NPV) do hipotálamo quanto em estruturas da lâmina terminal [órgão subfornicial (SFO), o órgão vasculoso da lâmina terminal (OVLT) e o núcleo pré-óptico mediano (MnPO)]. Tais observações foram reforçadas pela análise microscópica destas regiões cerebrais por imunofluorescência, que evidenciou aumento da imunomarcação para CB1R no NPV, NSO e SFO em animais submetidos a SS. Estes resultados também mostraram que a maioria dos terminais pré-sinápticos CB1R-positivos estão localizados predominantemente na porção ventral do NSO, na qual predominam neurônios vasopressinérgicos. Os dados mostram ainda que todas as respostas induzidas pela SS foram revertidas após a reintrodução dos líquidos (RL, água e NaCl 0,3M). Já no grupo PF, não foram observadas alterações na expressão de CB1R em nenhuma das áreas avaliadas. No entanto, após a RL, os animais PF apresentaram hipoosmolalidade plasmática e aumento da expressão de CB1R na LT, sendo este último efeito aparentemente mediado por um aumento da expressão deste receptor no SFO. Em animais normoidratados, a administração central de ACEA produziu um aumento significativo na ingestão alimentar, sendo esta resposta ausente nos animais submetidos a SS, apesar do aumento da expressão de CB1R no hipotálamo verificada neste grupo. Entretanto, o pré-tratamento com ACEA foi capaz de potencializar a ingestão de água induzida pela SS, não produzindo efeitos significativos sobre este parâmetro no grupo PF. Este estudo demonstrou ainda que a SS não alterou as concentrações plasmáticas de angiotensina II (ANGII), porém promoveu aumento signficativo nas concentrações plasmáticas de corticosterona, vasopressina (AVP) e ocitocina (OT), além de diminuir a secreção de peptídeo natriurético atrial (ANP). Em animais submetidos a SS, o prétratamento com ACEA potencializou a secreção de corticosterona e preveniu o aumento da secreção de AVP e OT. Por outro lado, não foram observados efeitos da administração de ACEA sobre a secreção de ANP e ANGII induzida pela SS. Após a RL, o grupo SS apresentou normalização das concentrações plasmáticas hormonais, não sendo observados quaisquer efeitos da administração de ACEA nestas condições experimentais. No grupo PF, por sua vez, após a RL foi observada diminuição na secreção de OT e aumento nas concentrações plasmáticas de ANGII, efeitos estes não alterados pelo pré-tratamento com ACEA. Em conjunto, nossos dados sugerem que o CB1R participa ativamente das respostas homeostáticas comportamentais e neuroendócrinas desencadeadas pela SS, sendo estas respostas especificamente relacionadas ao controle da homeostase hidrossalina e não secundárias à hipofagia induzida pela hiperosmolalidade. Desta forma, conclui-se que a participação do CB1R na homeostase hidroeletrolítica ocorre em paralelo e independentemente da modulação exercida por este receptor sobre a homeostase energética. / The endocannabinoid system (eCB) has been recognized as an important modulator of energy homeostasis and recent studies suggest that this system may play a possible integrator role on hydromineral homeostasis. Recent studies from our laboratory demonstrated the involvement of the type 1 cannabinoid receptor (CB1R) in the control of neurohypophyseal secretion in response to hypertonic extracellular volume expansion. Therefore, the present study aimed to clarify the involvement of the ECB system, particularly of CB1Rs, in neuronal, neuroendocrine and behavioral responses induced by 4 days of salt load (SS). Since the animals submitted to SS exhibit a well known state of hyperosmolality-induced hypophagia, we attempted to evaluate the integrated control of energy homeostasis and hydroelectrolytic balance through the introduction of a paired diet group (pair fed, PF). In order to achieve these goals, this study employed as a pharmacological tool the CB1R selective agonist, arachidonoyl-2\'-chloroethylamide (ACEA-0.1g/5L), administered intracerebroventricularly (icv). Initially, our work showed that SS increased the expression of CB1R in both supraoptic (SON) and paraventricular (PVN) nuclei of the hypothalamus, as well as in the structures of the lamina terminalis [subfornical organ (SFO), organum vasculosum of the lamina terminalis (OVLT) and median preoptic nucleus (MnPO)]. These observations were reinforced by the microscopic analysis of these brain regions by immunofluorescence, which showed increased immunostaining for CB1R in the PVN, SON and SFO in animals submitted to SS. These results also showed that most of the presynaptic CB1R-positive terminals are located predominantly in the ventral part of the SON, which is characterized by the presence of vasopressinergic neurons. The data also showed that all SS-induced responses were reversed after reintroduction of fluids (RF, water and 0,3M NaCl). On the other hand, no changes in the expression of CB1R in any of the evaluated areas were observed in the PF group. However, after RF, PF animals showed hypoosmolality and increased expression of CB1R in the LT, being the latter effect apparently mediated by increased expression of this receptor in SFO. In euhydrated animals, the central administration of ACEA produced a significant increase in food intake, being this response absent in animals submitted to SS, despite the increased expression of CB1R in the hypothalamus observed in this group. However, pretreatment with ACEA was able to potentiate SS-induced water intake, producing no significant effect on this parameter in the PF group. This study also demonstrated that SS did not alter plasma concentrations of angiotensin II (ANG II), but significantly increased plasma concentrations of corticosterone, vasopressin (AVP) and oxytocin (OT), and decreased the secretion of atrial natriuretic peptide (ANP). In animals submitted to SS, pretreatment with ACEA enhanced the secretion of corticosterone and prevented the increased secretion of AVP and OT. Moreover, no effect of ACEA was observed on the SS-induced ANG II and ANP secretion. After RF, the SS group showed normalization of hormonal plasma concentrations, and no effects of ACEA administration were verified under these experimental conditions. After RF, the PF group exhibited a decrease in OT secretion and increased plasma concentrations of ANG II, effects that were not altered by pretreatment with ACEA. Taken together, our data suggest that CB1Rs actively participate in behavioral and neuroendocrine homeostatic responses triggered by SS, and that these responses were specifically related to the control of hydromineral homeostasis and not secondary to the hyperosmolality-induced hypophagia. Therefore, we conclude that the involvement of CB1R in electrolyte homeostasis occurs in parallel and independently of the modulation exerted by this receptor on energy homeostasis.

La neurohormone ocytocine (OT) est de plus en plus étudiée pour son potentiel thérapeutique dans les troubles du comportement social, comme l'autisme, qui sont associés à une dérégulation de plusieurs systèmes de neurotransmission, notamment l'OT et la sérotonine (5-HT). Dans ce cadre, une étape importante afin de développer des médicaments basés sur des mécanismes biologiques est de caractériser les interactions entre l'OT et les autres neurotransmetteurs. La littérature sur les rongeurs montre que la relation entre OT et 5-HT est fortement impliquée dans plusieurs aspects du comportement social. Par ailleurs, nous avons récemment montré chez le sujet sain que le fonctionnement du récepteur 5-HT 1A (5-HT1AR) est modifié suite à l'administration d'OT.neuroJ'ai donc réalisé une première expérience chez des patients autistes en utilisant le scanner TEP avec le radiotraceur [18F]MPPF (spécifique du 5-HT1AR). Aucune différence n'est apparue, à l'état basal, entre 18 patients autistes et 24 sujets contrôles. Par ailleurs, l'OT n'a pas modifié le système 5-HT1AR. Enfin, alors qu'une corrélation entre la densité de 5-HT1AR et le volume de matière grise du striatum a été observé dans le groupe contrôle, cette relation était absente dans le groupe de patients. Ces résultats suggèrent une altération subtile du 5-HT1AR, ne pouvant être détectée qu'au niveau fonctionnel.Parce que le scanner TEP ne permet pas de dire si les changements observés sont dus à une libération de sérotonine ou à une modification directe du récepteur, j'ai réalisé une deuxième expérience chez 3 macaques rhésus, avec le [18F]MPPF et le [11C]DASB (marquant le transporteur de la 5-HT). Par rapport au placebo, l'OT injectée dans le ventricule latéral a significativement augmenté la liaison du [18F]MPPF dans l'amygdale et l'insula tandis que la liaison du [11C]DASB diminuait dans ces mêmes régions. Ainsi, nous pouvons dire que l'OT a provoqué la libération de 5-HT ainsi qu'une modification du 5-HT1AR dans ces régions importantes pour les comportements socio-émotionnels. Une étude par autoradiographie a confirmé cette interprétation.Ces expériences montrent qu'il existe une action régulatrice de l'OT sur la 5-HT chez le primate, mais que ce mécanisme est dérégulé chez les patients avec autisme. Cela ouvre donc la voie à l'investigation de traitements combinés exerçant un effet sur ces deux neurotransmetteurs / The neurohormone oxytocin (OT) is increasingly studied for its therapeutic potential in social disorders, like autism, which are associated with the deregulation of several neurotransmission systems, including OT and serotonin (5-HT). Hence investigating OT’s interactions with other neurotransmitters is a relevant step towards mechanism-based treatments. Studies in rodents demonstrated that the interaction between OT and 5-HT, is critical for several aspects of social behaviour. Moreover, using PET-scan in humans we have recently found that 5-HT 1A receptor (5-HT1AR) function is modified after intra-nasal oxytocin intake. Thus I performed a first experiment in which intra-nasal OT was administered to patients with autism undergoing a [18F]MPPF (a 5-HT1AR radiotracer) PET scanner, in order to study their basal serotonergic system and to look if the oxytocin modulates the 5-HT1AR system. I found no differences of baseline 5-HT1AR concentration between 18 autistic subjects and 24 controls. Critically, in patients, OT did not induce changes on the 5-HT1AR system. Moreover, in controls, there was a correlation between 5-HT1AR and grey matter volume in the striatum, that was not observed in patients. These results suggest a subtle disruption of patients’ serotonergic system, that can only be seen at the functional level. Because PET scan does not tell us if the observed modification is due to a change in 5-HT1AR or 5-HT concentration, I performed a second PET scan experiment on 3 macaque monkeys, using [18F]MPPF and [11C]DASB, that marks the serotonin transporter. Compared to placebo, OT injections in the lateral ventricle significantly reduced [11C]DASB binding potential in right amygdala, insula and hippocampus whereas [18F]MPPF binding potential increased in right amygdala and insula. Thus we reproduced results obtained in healthy humans and extended it by suggesting that OT provokes the release of 5-HT in key limbic regions involved in socio-emotional processing. These results were confirmed with autoradiography.Taken together, these experiments indicate that OT modulates 5-HT release in primates, but this mechanism is disrupted in patients with autism. This opens ways to investigate combined OT/5-HT treatments, especially since FDA approved drugs targeting the two systems are already available for use in patients with autism

Interagir avec autrui est crucial pour notre survie. Différentes études ont mis en évidence le rôle de l'ocytocine (OT) dans la sociabilité et l'affiliation. La première partie de notre travail montre qu'il y a un lien entre la concentration d'ocytocine plasmatique et l'ocytocine centrale et que les deux sont corrélées au niveau d'extraversion des individus. L'OT plasmatique corrèle aussi au volume de l'amygdale et de l'hippocampe, deux régions cérébrales importantes pour le comportement social. Nous montrons également que l'administration d'OT entraine une modification (augmentation) de la perception subjective de la sociabilité. L'ensemble de ces résultats suggère que l'OT constitue un biomarqueur de la personnalité sociale et pourrait servir au diagnostic de pathologies sociales comme l'Autisme. Nous avons étudié le fonctionnement central de l'OT et particulièrement son interaction avec la sérotonine (5-HT), impliquée elle aussi dans la régulation du comportement social. Avec la Tomographie par Emission de Positon (TEP) et grâce à un radioligand ([18-F]MPPF) spécifique des récepteurs 5-HT1A de la 5-HT nous montrons que l'administration d'OT entraine, chez le sujet sain une augmentation du potentiel de liaison (BP) du MPPF traduisant une modification de l'activité de la 5 HT au niveau du raphe, de l'amygdale/hippocampe, de l'insula et du cortex orbitofrontal, régions clés pour le traitement du comportement social. Les patients Asperger démontrent une diminution du MPPF BP par rapport aux contrôles au niveau de ces mêmes régions, différence qui s'annule par la prise d'OT. Ces résultats confirment le potentiel thérapeutique de l'OT et ouvrent de nouvelles pistes de recherche visant à intégrer la relation entre les neurotransmetteurs dans les futurs traitements. L'ensemble de ce travail place l'ocytocine au coeur de la physiologie du comportement social et suggère son utilisation tant au niveau du diagnostic que de la prise en charge de l'Autisme / Interacting with others is crucial for human fitness. In the past decade, there has been a growing interest for oxytocin (OXT) and its implication in social behavior. In the first section of this work we show that peripheral and central concentrations of OXT are correlated. Peripheral and central OXT are also correlated with subjects’ extraversion and with the volume of amygdala and hippocampus, two brain regions important for the regulation of social behavior. Interestingly, we show that OXT intake increases the subjective perception of subjects’ sociability. These findings suggest that OXT can be considered a biomarker of social behavior, thus opening the possibility of using this hormone in the screening process of psychiatric disorder like Autism. In a second section, we focused on the central action of OXT and in particular its interaction with another neurotransmitter also essential for social behavior: the serotonin (5-HT). We assessed OXT effect on the central serotoninergic activity in healthy subjects using the Positon Emission Tomography (PET) thanks to a radiotracer ([18-F]MPPF) specific for the 5-HT1A receptors and known to be localised in brain regions important for social processing. Our results show that oxytocin administration increases MPPF binding potential (BP) in raphe nuclei, right amygdala, hippocampus and orbitofrontal cortex. Interestingly, Asperger patients showed a decrease in MPPF BP in these regions compared to controls. This difference disappeared after oxytocin. These results strengthen the role of oxytocin in social behavior and underline the therapeutic potential of this neuromodulator for psychiatric disorders implicating both serotonin and oxytocin dysfunctions

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The 1980's heralded the discovery and identification of extra-pituitary sources of the neurohypophysial hormone oxytocin in non-neural tissues of several animal species. The presence, location and biosynthesis of significant amounts of oxytocin in the ovarian corpus luteum was followed by the immunocytochemical demonstration of an oxytocin-like peptide in the testicular interstitial cells. Leydig cells, which comprise up to 80% of the testicular intertubular cell population, are known to synthesize testosterone in situ. Indirect evidence indicated that an oxytocin-like peptide was also present in Leydig cells. The question arose whether this peptide was synthesized de novo by Leydig cells or was taken up and stored by the cells following biosynthesis at some other intra- and/or extra-gonadal source(s). Since luteinizing hormone (LH) and ascorbate are known to augment the production of oxytocin in ovarian granulosa cells, varying concentrations of these two stimulants were used to monitor the biosynthesis of oxytocin from isolated Leydig cells in culture. / Ph. D.

réalisé avec la codirection de Marek Jankowski / Introduction: L’ocytocine (OT) était connue pour ses effets lors de la parturition et de la lactation. Depuis quelques années, d’autres rôles de l’OT ont été proposés. Ainsi, la découverte de l’OT et de son récepteur (OTR) dans le cœur a suggéré le rôle fonctionnel de cette hormone dans cet organe. Aujourd’hui, il existe une controverse concernant l’implication de l’OT dans la régulation de la pression artérielle (PA). Des études additionnelles sont donc requises pour préciser le rôle de l’OT dans le contrôle de la PA. C’est dans ce cadre que se situe la présente étude. Méthodes: Deux types d’expériences ont été faites: Une pour l’étude des paramètres métaboliques et l’autre pour les paramètres cardiovasculaires. Pour la première, l’OT (0.04 mg/kg) a été testée pour son effet métabolique. Les rats SD sont injectés avec l’OT et immédiatement placés dans des cages métaboliques individuelles et adaptées pour recueillir les urines. Les urines recueillies sur 3 heures nous ont permis de mesurer la diurèse, la natriurèse et la kaliurèse chez les rats. Pour le 2ème type, des rats spontanément hypertendus (SHR) et des Sprague-Dawley (SD) ont subi une chirurgie pour l’implantation de la sonde de télémétrie. Après 10 jours de récupération, nous avons commencé l’expérience qui s’est déroulée en 2 séries: la série des injections intraveineuses (i.v.) (0.04, 0.08, 0.1, 0.2 et 0.4 mg/kg en une seule injection) et la série des injections sous-cutanées (s.c.) (0.5 et 1 mg/kg/jour pendant 5 jours d’injection). La pression artérielle (PA), la fréquence cardiaque (FC) et de l’activité des rats ont été mesurées continuellement pendant toute l’expérience. Résultats: En i.v. la plus petite dose d’OT (0.04 mg/kg/0.3 ml) utilisée pour les effets rénaux a amené une diurèse significative, montre une tendance de natriurèse et de diminution de kaliurèse. Cette dose et celle d’OT (0.08 mg⁄kg⁄0.3 ml) sont sans effets sur la PA mais diminuent la FC des SHR et des SD (seulement les nuits). Pour les doses élevées en i.v. (0.1, 0.2 et 0.4 mg/kg d’OT), à l’exception de l’effet vasopresseur transitoire observé avec OT 0.4 mg/kg chez SD, l’OT 0.1 et 0.2 mg/kg ont diminué la PA. Les doses (0.2 et 0.4 mg/kg) d’OT ont diminué la PA chez les SHR. Elles ont augmenté la FC en journée aussi bien chez les SD que chez les SHR pendant que 0.1 mg/kg l’a diminuée. Pendant les nuits, c’est seulement la dose de 0.4 mg/kg qui a un effet sur la FC qu’elle diminue aussi bien chez les SD que les SHR. Les doses de 0.5 et 1 mg/kg injectées en s.c. ont diminué significativement la PA chez les SHR. Mais, chez les SD c’est l’OT à la dose de 1 mg/kg qui a amené une baisse de PA. À l’exception de OT 0.5 mg/kg/jour qui a augmenté la FC et l’activité chez les SHR en journée et ce au cours des injections, l’OT en s.c. a également entraîné une diminution de la FC et de l’activité. Conclusion: Ces résultats démontrent que l’OT intervient dans la régulation de la PA et la FC et les effets de l’OT dépendent de la souche de rats, de la dose, de la voie d’administration et du moment d’enregistrement des paramètres cardiovasculaires (jour ou nuit). Parlant de dépendance des résultats en fonction des voies d’administration, force est de signaler qu’avec les injections s.c. l’effet hypotenseur de l’OT est puissant et sans équivoque. Cela serait dû au fait que la duré de vie de l’OT est très courte (5 à 10 minutes) quand elle entre dans le sang. Ainsi, contrairement à la voie i.v., l’efficacité de l’OT en s.c. résulterait de sa libération lente dans le sang et donc toute la quantité administrée en s.c. ne se dégrade pas d’un seul coup. / Introduction: Oxytocin (OT) is known for its effects during parturition and lactation. In recent years, new roles of OT have been brought to light. Thus, the discovery of OT and its receptors (OTR) in the heart suggest a functional role in the body. Nowadays, the involvement of OT in blood pressure (BP) regulation is still controversial. Additional studies are therefore required to accurately determine the role of OT in the control of BP. Methods: Two types of experiments were carried out: Diuretic effect: conscious male, Sprague-Dawley rats were administered OT intravenously (0.04 mg/kg) and immediately placed in metabolic and individual cage; urine was collected and measured every hour for 3 hours. Urine measurement allowed diuresis, natriuresis and kaliuresis to be determined Telemetry: telemetry implants and catheters were inserted into the abdominal aorta of spontaneously hypertensive (SHR) and Sprague-Dawley (SD) rats. After 10 days (of necessary recovery), heart rate (HR), BP and animal locomotor activities were measured continuously. The same experiment was done on two batches of rats. Different doses of OT: 0.04; 0.08; 0.1, 0.2 or 0.4 mg/kg were injected once by intravenous (i.v) route. After each injection, we waited for the normalization of BP and HR before the next dose. Further more, 5 consecutive injections of OT were made (0.5 and 1 mg/kg) subcutaneously (s.c.). Results: The dose of 0.04 mg/kg of OT administrated for renal effects led to significant diuresis, a tendancy in natriuresis and kaliuresis decreased with no effect on BP. That dose as well as 0.08 mg/kg decreased HR in SHR and SD rats (only in the night). Whereas the highest doses in i.v. (0.1, 0.2 et 0.4 mg/kg d’OT), except a transient vasopressor effect observed with the OT 0.4 mg/kg in SD rats, OT 0.1 and 0.2 mg/kg decreased BP. OT 0.2 and 0.4 mg/kg decreased BP in SHR but increased HR during the days in both strains. The dose of 0.4 mg/kg led to a decrease of HR in SHR and in SD rats. The s.c. injections (0.5 and 1 mg/kg) of OT led to a significant decrease in BP in SHR, whereas in SD rats the lowering was only significant with a dose OT 1 mg/kg. HR significantly decreased in both strain with 1 mg/kg, whereas with 0.5 mg/kg, HR increased in SHR only and during the day. Conclusion: These results demonstrate that oxytocin acts on blood pressure and heart rate depending on strain, dose and route of administration. It’s important to point out that with s.c. injections the hypotensive effect of OT is powerful and unequivocal. This is probably because OT administered s.c. is slowly released into the bloodstream. Therefore the entire amount administered s.c. does not degrade at once and leads to the effectiveness of s.c. results.

A Ansiedade de Performance Musical (APM) é considerada uma condição caracterizada por apreensão persistente e intensa diante da apresentação musical pública, desproporcional ao nível de aptidão, treino e preparo do músico. Os sintomas ocorrem em uma escala de gravidade contínua que em seu extremo afeta a aptidão musical devido a sintomas ao nível físico, comportamental e cognitivo, além de déficits no processamento cognitivo e cognição social, em especial na capacidade de reconhecimento de expressões faciais de emoção (REFE). Assim, intervenções que possam corrigir esses vieses com eficácia são necessárias. Nesse sentido, os objetivos dos estudos que compõem esta tese são: a) avaliar o REFE em músicos com diferentes níveis de APM; b) realizar uma revisão sistemática da literatura de forma a trazer evidências sobre os efeitos das substâncias ansiolíticas no REFE em indivíduos saudáveis; e c) conduzir um ensaio clínico, cross over, randomizado, duplo cego e controlado por placebo para testar o efeito da OCT em músicos com alto/baixo nível de APM no REFE, nos indicadores de humor/ansiedade e na cognição negativa. Método: Para se atender ao objetivo realizou-se um estudoobservacional, transversal, com 150 músicos de ambos os sexos, de diferentes estilos musicais, os quais realizaram uma tarefa de REFE, após serem classificados quanto aos níveis de APM.Para atender-se o segundo objetivo conduziu-se uma revisão sistemática da literatura seguindo-se as diretrizes do PRISMA e do Cochrane Handbook for SystematicReviewsofInterventions. Por fim, para alcançar o terceiro objetivo, 43 músicos do sexo masculino, de diferentes estilos musicais participaram de um ensaio clínico, randomizado, cross over, controlado por placebo, no qual testou-se a eficácia de 24UI de OCT intranasal. Resultados:Os resultados evidenciaram que os músicos com altos níveis de APM apresentam um prejuízo global no REFE, expresso, sobretudo pela dificuldade no reconhecimento adequado da emoção alegria, a qual está associada aos sinais de aprovação social. A revisão da literatura evidenciou que poucas substâncias foram testadas até momento, e que as alterações no REFE foram específicas e dependentes do mecanismo de ação da substância no sistema nervoso central, dose e forma de administração. O ensaio clínico apontou uma melhora no reconhecimento da emoção alegria,somente em músicos com altos níveis de APM, após o uso agudo da OCT. Conclusão:O REFE mostrou-se alterado de forma específica em músicos com altos níveis de APM, os quais podem ser corrigidos através do uso da OCT intranasal, a qual desponta como uma substância promissora para o uso clínico / Musical Performance Anxiety (MPA) is considered a condition characterized by persistent and intense apprehension in circumstances involving public musical presentation, disproportionate to the musician\'s aptitude level, training and preparation. The symptoms occur on a continuous severity scale that affects, at its extreme, the musical aptitude due to symptoms at the physical, behavioral and cognitive levels, as well as interfering with cognitive processing and social cognition, especially in the facial emotion recognition (FER) ability. Thus, interventions that can effectively correct these deviances are necessary. Therefore, the aims of the studies that compose this thesis are: a) to analyze the (FER) in musicians with different levels of MPA; b) to carry out a systematic review of the literature in order to present evidence about the effects of anxiolytic substances on FER in healthy individuals; c) to conduct a randomized, double-blind, placebo-controlled, cross-over clinical trial to test the OT effect on musicians with high/low MPA level in FER, mood/anxiety indicators and negative cognition. Methods: To achieve the first aim of this study, a cross-sectional, observational study was conducted with 150 musicians of both sexes, of different musical styles, who performed a FER task, after being classified according to the MPA levels. As for the second aim, a systematic literature review was carried out in accordance with the PRISMA guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. Finally, for the third aim, 43 male musicians of different musical styles have participated in a randomized, placebo-controlled, cross-over clinical trial in which the 24UI of intranasal OT efficiency was tested. Results: The results showed that musicians with high levels of MPA present a global impairment in FER, expressed mainly by the difficulty in the appropriate recognition of the emotion of joy, which is associated with signs of social approval. The review of the literature showed that few substances have been tested so far, and that the changes in FER were specific and dependent on the substance mechanism of action in the central nervous system, dose and form of administration. The clinical trial presented an improvement in the recognition of the emotion of joy, only in musicians with high levels of MPA, after the OT acute use. Conclusion: The FER was specifically altered in musicians with high levels of MPA, which can be corrected with the use of intranasal OT, which appears as a promising substance for clinical use