Submitted by Natalie Mendes (nataliermendes@gmail.com) on 2015-07-28T00:17:52Z No. of bitstreams: 1 Disserta??o - C?ssio Santana.pdf: 10345998 bytes, checksum: 41cc3a308f7a72f1c4e10cc1ee2fe345 (MD5) / Made available in DSpace on 2015-07-28T00:17:52Z (GMT). No. of bitstreams: 1 Disserta??o - C?ssio Santana.pdf: 10345998 bytes, checksum: 41cc3a308f7a72f1c4e10cc1ee2fe345 (MD5) Previous issue date: 2014-02-05 / Funda??o de Amparo ? Pesquisa do Estado da Bahia - FAPEB / Chagas disease is a zoonosis caused by the hemoflagellate protozoan Trypanosoma cruzi, which affects millions of people in Latin America. Disease treatment is based on the use of two drugs, benznidazole and nifurtimox, which present low cure rates in the chronic phase of the disease as well as generating a number of adverse side effects. In this context, the development of new therapies for a better treatment of Chagas disease is necessary. In this study we investigated the anti-T.cruzi potential of physalins and betulinic acid, plant-based isolated steroids, in addition to synthetic derivatives from the latter, in in vitro assays. Our results demonstrate a high trypanocidal activity of physalins B and F and of the derivative BA5 against trypomastigote forms and on the processes of invasion and development of these on peritoneal macrophages. Electron microscopy revealed that physalin B or BA5 derivative treatment resulted in ultrastructural changes in the plasma membrane, Golgi apparatus, kinetoplast and endoplasmic reticulum of trypomastigotes forms. Additionally, these compounds contributed to the formation of atypical vacuoles in the appearance of myelin figures, which were labeled with MDC to confirm their identity as autophagic vacuoles. Flow cytometry analysis revealed that parasite death occurred mainly by necrosis. When combined with benznidazole, physalin B, physalin F or BA5 derivative, resulted in a higher anti-T. cruzi activity against amastigotes when compared to the compounds tested alone. These results indicate that steroids, such as physalins B and F and the derivative BA5, are potential candidates for an alternative treatment of Chagas disease. / A doen?a de Chagas ? uma zoonose causada pelo protozo?rio hemoflagelado Trypanosoma cruzi, que afeta milh?es de pessoas na Am?rica Latina. O tratamento dessa enfermidade se baseia na utiliza??o de dois f?rmacos, o benzonidazol e o nifurtimox, que possuem baixa taxa de cura na fase cr?nica da doen?a, al?m de gerarem uma s?rie de efeitos colaterais. Nesse contexto, o surgimento de novos medicamentos para uma quimioterapia mais adequada da doen?a de Chagas torna-se necess?rio. Neste estudo investigamos o potencial anti-T. cruzi de esteroides isolados de plantas, fisalinas e ?cido betul?nico, assim como de derivados sint?ticos deste ?ltimo, em ensaios in vitro. Nossos resultados demonstram uma elevada atividade tripanocida das fisalinas B e F e do derivado BA5 contra formas tripomastigotas e sobre os processos de invas?o e desenvolvimento destas em macr?fagos peritoneais. Atrav?s de ensaios de microscopia eletr?nica foi poss?vel observar que o tratamento com a fisalina B ou com o derivado BA5 causa altera??es ultraestruturais na membrana plasm?tica, complexo de Golgi, cinetoplasto e ret?culo endoplasm?tico das formas tripomastigotas, al?m da forma??o de vac?olos at?picos e o aparecimento de figuras miel?nicas, que foram marcadas com MDC para confirmar a sua identidade como vac?olos autof?gicos. An?lises por citometria de fluxo revelaram que a morte parasit?ria ocorre principalmente por necrose. A combina??o da fisalina B, da fisalina F ou do derivado BA5 com o benzonidazol resultou em uma maior atividade anti-T. cruzi frente a formas amastigotas quando comparados aos compostos testados de forma isolada. Estes resultados indicam que esteroides, tais como as fisalinas B e F e o derivado BA5, s?o potencias candidatos para o tratamento alternativo da doen?a de Chagas.

Made available in DSpace on 2017-07-10T14:17:20Z (GMT). No. of bitstreams: 1 Lana_Branai.pdf: 2297634 bytes, checksum: 8dbbaa1b059e5e38dcdd38ba4a303557 (MD5) Previous issue date: 2016-03-04 / Nowadays, the search for beauty, has caused health problems associated with the use of anabolic androgenic steroid (AAS) and even strenuous exercise, and the male reproductive system is the subject of studies to be sensitive to changes in the concentration of this type of hormone; these changes may also occur with increasing age, causing changes in androgen-dependent organs, like the epididymis. This study aimed to verify if treatment with AAS associated or not to exercise, in Sprague-Dawley rats alters the morphology of the epididymis in adult rats and its chronic effects in the elderly. The training was conducted by jumping into the water, weighing overloading, being considered as resistance exercise in water. The AAS administration occurred by intramuscular injection of nandrolone decanoate (10 mg / kg / week). Epididymal samples were subjected by histological routine of hematoxylin and eosin for morphological and morphometric analysis. It was analyze all parts of the epididymis (initial segment, caput, corpus and cauda) of 56 Sprague-Dawley rats, virgins, with 13 weeks old, divided into eight groups with seven animals each: GC - adults and sedentary; GCi - elderly and sedentary; GN - adults, sedentary treated with AAS; GNi - elderly, sedentary treated with AAS; GE - adults treated with exercise; GEi - elderly treated with exercise; GNE - adults, exercise and treatment with AAS; GNEi - elderly, exercise and treatment with AAS. The results show significant changes in duct diameters; the GE was lower when compared to other groups, and the groups that were used anabolic steroids, had a larger diameter than the other, and these changes occurred mainly in the initial segments. The epithelial height in the initial segment was also considered higher in the groups that administered AAS. The elderly groups tend to return to normal, increasing the parameters of epithelial height and diameter when these were decreased, and lowering them when they were enlarged when compared with the related adult group (with common variable), except at the tail of GNEi. As the results of this study, we can conclude that both treatment in adulthood, with exercise and the use of AAS, changes morphometric and morphological parameters of the epididymis, and its chronic effects can be diminished with age. / Atualmente, a procura pela beleza estética, tem causado problemas de saúde associados ao uso de esteroides androgênicos anabolizantes (EAAs) e até mesmo a exercícios físicos intensos. O sistema genital masculino é alvo de estudos por ser sensível a mudanças na concentração desse tipo de hormônio; essas alterações também podem ocorrer com o aumento da idade, influenciando órgãos androgênio-dependentes, como o epidídimo. Nesse sentido, objetivou-se com esse estudo, verificar se o tratamento com EAAs associado ou não ao exercício físico resistido, em ratos Sprague-Dawley, altera a morfologia do Epidídimo em ratos adultos e seus efeitos a longo prazo em idosos. Foram analisadas todas as porções dos epidídimos (segmento inicial, cabeça, corpo e cauda) de 56 ratos, virgens, da linhagem Sprague-Dawley (com 13 semanas de vida ao iniciarem o experimento), separados em oito grupos com sete animais cada: GC - adultos e sedentários; GCi - idosos e sedentários; GN - adultos, sedentários, tratados com EAA; GNi - idosos, sedentários, tratados com EAA; GE - adultos tratados com exercício; GEi - idosos tratados com exercício; GNE - adultos, exercício e tratamento com EAA; GNEi - idosos, exercício e tratamento com EAA. O treinamento realizado foi exercício resistido em meio aquático (através de saltos na água, com sobrecarga) com duração de oito semanas (três vezes na semana). A administração de EAAs ocorreu pela aplicação intramuscular de Decanoato de Nandrolona (10 mg/kg/semana) também durante oito semanas (duas vezes na semana). Amostras epididimárias passaram pela rotina histológica de hematoxilina e eosina para análise morfológica e morfométrica. Os resultados mostraram alterações significativas nos diâmetros de ductos, sendo que o GE foi menor quando comparado ao controle, e, nos grupos em que foram utilizados anabolizantes, tiveram diâmetro aumentado significativamente, e essas alterações ocorreram principalmente nos segmentos mais iniciais. A altura epitelial, no segmento inicial, também foi maior nos grupos em que foi utilizado anabolizante. Os grupos idosos tenderam a retornar a normalidade, aumentando os parâmetros de altura e diâmetro quando esses estavam diminuídos, e diminuindo-os quando estavam aumentados em comparação ao grupo adulto relacionado (com variável em comum), a não ser na cauda, do GNEi, em que houve aumento significativo. Achados morfológicos indicaram presença de debris celulares em lúmen (GN e GNEi) e infiltrados intersticiais (GN, GNE, GE e GCi). Conforme os resultados desse estudo, pôde-se concluir que tanto o tratamento na fase adulta com exercício, quanto à utilização de EAAs altera parâmetros morfométricos e morfológicos do epidídimo, e que seu efeito crônico pode ser diminuído com a idade.

Este trabalho teve por objetivo descrever os perfis hormonais do ciclo ovariano de cinco exemplares adultos de C. penicillata, mantidas no Parque Municipal Quinzinho de Barros em Sorocaba, SP. As amostras de fezes foram colhidas diariamente, sempre pela manhã, durante três meses e mantidas congeladas até o processamento laboratorial. Após a extração com solventes orgânicos, as mensurações foram efetuadas com o uso da técnica de radioimunoensaio (RIE). Para as mensurações dos metabólitos hormonais foram utilizados conjuntos comerciais validados para o uso em matriz fecal de C.penicilatta. Os resultados mostraram que duas fêmeas estavam ciclando e três estavam gestantes. Para as fêmeas que apresentaram ciclicidade ovariana o ciclo teve duração média de 23.5 ±9, 9 dias, sendo que as durações das fases lúteas e foliculares foram de 13,25 dias ± 9,46 dias e de 10,25 ±7,2 dias, respectivamente. Entre as outras três fêmeas, duas tiveram suas gestações confirmadas, parindo filhotes e uma teve suspeita de ter sofrido abortamento .Para as que tiveram suas gestações confirmadas, a média das concentrações dos metabólitos fecais de progesterona foi de 4527,19 ± 3667,8 ng/g para o terço medio enquanto a média do terço final foi de 2974±2471,9 ng/g. As médias obtidas para as concentrações de metabólitos de estrógenos nos terços medio e final foram respectivamente de 1401,41± 1034,4 ng/g e 1546,67± 1227,2 ng/g. Para a fêmea que teve suspeita de abortamento foram confeccionados gráficos dos valôres obtidos das concentrações de ambos os metabólitos hormonais para o período anterior e posterior a data presumida do evento e comparadas as suas médias . A média da concentração dos metabólitos fecais de progesterona antes do suposto abortamento foi de 1466,22± 784,36 ng/g e para o período posterior ao suposto evento foi de 813 ± 614,66 ng/g Para as médias das concentrações de metabólitos fecais de estrógenos, os resultados obtidos foram de 745,65± 747,39 ng/g antes e 212,42 ±331,84 ng/g depois do suposto evento. As analises das concentrações de metabóltios fecais dos hormonios esteroides, mostrou-se uma ferramenta efficiente e adequada para estudos sobre a ciclicidade ovariana e gestação do C. penicillata. / This study had as objective to describe the hormonal profiles of the ovarian cycle of five adult females of C.penicillata, from the Parque Municipal Quinzinho de Barros in Sorocaba, SP. The fecal samples were collected on a daily basis, always in the morning, during three months and then frozen until their processing. After extraction with organic solvents, the measurements were conducted with radioimmunoassay (RIA) .For the measurements of the hormonal metabolites comercial kits were used and validated for C.penicillata. The results showed two females with ovarian cyclicity and three females that were pregnant. For the females that presented ovarian cyclicity the duration of the ovarian cycle had an average of 23.5 ± 9.9 days , where the duration of the luteal and follicular phases were of 13.25 ±9.46 days and 10.25±7.2 days, respectively. Of the other three females, two had their pregnancys confirmed by the birth of their young and one was suspected to have suffered abortion. For the females that had their pregnancys confirmed , the mean of the fecal progesterone metabolites concentration was of 4527.19 ± 3667.8 ng/g for the second trimester, as where for the third trimester it was of 2974 ±2471.9 ng/g. The means for the estrogen fecal metabolites concentrations for the second and third trimester were of 1401.41 ± 1034.4 ng/g and 1546.67 ± 1227.2 ng/g. For the female that was suspected to have had an abortion graphs were used with values obtained from both fecal metabolites concentrations from before and after the presumed date of the event and the means were compared. The mean of progesterone fecal metabolites concentrations before the abortion was of 1466.22 ± 784.36 ng/g and for the period after the abortion it was of 813 ± 614.66 ng/g. For the estrogen fecal metabolites concentration mean, the results obtained were of 745.65 ± 747.39 ng/g for the before period and 212.42 ±331.84 for the after period. The analysis of the fecal metabolites steroids hormone concentration, showed to be an efficient tool for the studies of the ovarian cycle and gestation period in the C.penicillata.

No primeiro capitulo deste trabalho, é apresentada a classificação e a importância dos esteróides sexuais para manutenção da vida humana. Na seqüência, o próximo capítulo mostra aspectos gerais sobre eletroforese capilar, tais como modo de operação, terminologia utilizada e considerações sobre o fluxo eletrosmótico e mobilidade eletroforética. O terceiro capítulo exibe um estudo da interação solvente/micela de SDS/soluto, baseado na otimização da geometria da molécula, análise conformacional, com descritores moleculares e modelos de regressão, baseados no coeficiente de partição. Foram realizadas medidas experimentais dos tempos de retenção, de onze esteróides, a partir da MEKC, em eletrólitos modificados por solvente, conforme suas propriedades de seletividade. O efeito do solvente na modulação da retenção do soluto foi discutido em termos da LSER, a qual indicou a concentração total de solvente no meio como o principal fator de controle do tempo de retenção. A separação dos compostos selecionados, na melhor condição, foi testada em um extrato de uma amostra de urina obtida de um voluntário humano - sexo feminino - em fase de puberdade. A composição do eletrólito (20 mmol L-1 SDS, 20% EtOH e 20 mmol L-1 tetraborato de sódio a pH 9,4) proposta pode ser aplicada potencialmente para a determinação de estrógenos em estudos clínicos (0.80% C.V. para tempo de migração e 2.5% C.V. para área do pico, n = 5). Posteriormente, já no quarto capítulo, o uso do planejamento fatorial foi uma forma rápida de otimizar a composição do eletrólito para separar uma mistura-teste com onze esteróides. Uma triagem das variáveis indicou que as concentrações de ACN, SDS e &#946;-CD mais influenciavam a resolução e o tempo de análise. O estudo dos efeitos mostrou que a interação ACN/ &#946;-CD e a ACN mais contribuía para resolução dos pares críticos. O sistema micelar constituído por 20 mmol L-1 SDS, 10% ACN, 5 mmolL-1 &#946;-CD e 20 mmolL-1 TBS, pH 9.2, foi o meio no qual se obteve a melhor resposta em relação à resolução dos pares críticos e tempo de análise Este método foi usado avaliar a presença dos esteróides em extrato etanólico de excrementos de Pantera onca. Em outra etapa um método MEEKC foi desenvolvido e validado para a determinação de 17 &#946;-estradiol em adesivo transdérmico usando uma microemulsão contendo 0.5% (m/m) acetato de etila, 1.2% (m/m) butan-1-ol, 0.6% (m/m) SDS, 15% (v/v) ACN e 82.7% (m/m) TBS 12 mmol L-1 , pH 9.4. Foi obtida aceitável precisão (<1.2% RSD), linearidade, sensibilidade (LOD=0.89 &#181;g/mL; LOQ=2.68 &#181;g/mL) e recuperação (100.4 &#177;0.9 %). Por fim, o ultimo capítulo traz o desenvolvimento e validação de um método via MEKC para determinação etinilestradiol em comprimidos usando um eletrólito constituído por 20 mmol L-1 SDS, 22,5 % (v/v) ACN e 10 mmol L-1 TBS, pH 9,2. Apresentando valores de precisão (<1.0% RSD), linearidade, sensibilidade (LOD=0.84 &#181;g/mL; LOQ=2.55 &#181;g/mL) e recuperação (99.4&#177; 0.7 %) aceitáveis. E ainda, via MEEKC, para determinação simultânea de etinilestradiol e levonorgestrel usando uma microemulsão contendo: 0.5% (m/m) acetato de etila, 1.2% (m/m) butan-1-ol, 0.6% (m/m) de SDS, 15% (v/v) etanol e 82.7% (m/m) TBS 12 mmol L-1 , pH 9.2. Injeção: pelo outlet 3s/0.5 psi. Com alta precisão (<0.8% RSD), linearidade, sensibilidade (LOD=1.04 &#181;g/mL; LOQ=3.15 &#181;g/mL para etinilestradiol e LOD=1.35 &#181;g/mL; LOQ=4.10 &#181;g/mL para o levonorgestrel) e recuperação (98.6&#177; 0.8 % para etinilestradiol), os métodos mostraram-se sensíveis e precisos para serem utilizados no controle de qualidade de formulações farmacêuticas. / In the first chapter of this work, the classification and importance of the sexual steroids for maintenance of the life human is presented. The next chapter presents general aspects on capillary electrophoresis, such as operation, terminology and considerations on the electroosmotic flow and electroforetic mobility. The third chapter shows a study of interaction solvent/ SDS micelle /solute, based on the optimization of molecule geometry, conformational analysis, with molecular descriptors and regression models, based in the partition coefficient. The retention times were measured experimentally for eleven steroids, in MEKC electrolytes modified by solvents. The solvent effect in modulating the retention of solute was explaned in terms of LSER, which indicated the total organic solvent percentage in the electrolyte as the main factor controlling retention. The separation of selected compounds, in the best condition, was tested in urine extract sample from a human volunteer - feminine -1 sex - in puberty phase. The composition of the proposed electrolyte (20 mmol L-1 SDS, 20% (v/v) EtOH and 20 mmol L-1 sodium tetraborate, pH 9.4) can potentially be applied for determination of estrogens in clinical studies (0.80% C.V. for migration time and 2.5% C.V. for peak area, n = five consecutive injections). Later, in fourth chapter, the use of factorial design was introduced to optimize the composition of the electrolyte to separate a mixture-test with eleven steroids. The selection of variable indicated that the concentrations of ACN, SDS and &#946;-CD influenced the most resolution and analysis time. The study of the effect showed that interaction ACN/ &#946;-CD and ACN were important for resolution of the critical pairs. The micelle system constituted of 20 mmol L-1 SDS, 10% (v/v) ACN, 5 mmolL-1 &#946;-CD and 20 mmolL-1 TBS, pH 9.2, was composition to achieve resolution of the critical pairs and analysis time. This method was used to evaluate the presence of the steroids in fecal ethanolic extract of Pantera onca. In another work a MEEKC method was developed and validated for determination of 17 &#946;-estradiol in transdermical adhesive using a microemulsion containing 0.5% (w/w) ethyl acetate, 1.2% (w/w) butan-1-ol, 0.6% (w/w) sodium dodecyl sulfate, 15% (v/v) ACN and 82.7% (w/w) 12 mmol L-1 sodium tetraborate aqueous buffer at pH 9.4. Acceptable precision (<1.2% RSD), linearity, sensitivity (LOD=0.89 &#181;g/mL; LOQ=2.68 &#181;g/mL) and recovery (100.4&#177; 0.9 % at three concentration levels) were obtained. The last chaper, the development and validation of MEKC method for determination of ethynylestradiol in a commercial tablet formulation using a micellar medium containing, 25 mmol L-1 sodium dodecyl sulfate, 22,5% (v/v) ACN and 10 mmol L-1 sodium tetraborate aqueous buffer at pH 9.2 was presented. Acceptable precision (<1.0% RSD), linearity, sensitivity (LOD=0.84 &#181;g/mL; LOQ=2.55 &#181;g/mL) and recovery (99.8&#177; 1.8 % at three concentration levels) were obtained. A MEEKC method for the simultaneous determination of ethynylestradiol and levonorgestrel using microemulsion containing 0.5% (w/w) ethyl acetate, 1.2% (w/w) butan-1-ol, 0.6% (w/w) sodium dodecyl sulfate, 15% (v/v) ethanol and 82.7% (w/w) 12 mmol L-1 sodium III tetraborate aqueous buffer at pH 9.2 was developed. High precision (<0.8% RSD), linearity, sensitivity (LOD=1.04 &#181;g/mL; LOQ=3.15 &#181;g/mL to ethynylestradiol and LOD=1.35 &#181;g/mL; LOQ=4.10 &#181;g/mL to levonorgestrel) and recovery (98.6&#177; 0.8 % at three concentration levels of ethynylestradiol) were obtained.

Abstract not available

<p>A new group of anabolic androgenic steroid (AAS) users has developed during the last two decades. This group consists primarily of young men interested in improving their physical appearance. Within this group, AAS are sometimes used together with other illicit drugs, alcohol and nicotine. Brutal and violent crimes have been committed under the influence of AAS, possibly because of AAS psychiatric side effects, ranging from increased aggression and psychosis to depression. Unfortunately, the biochemical mechanisms behind these effects are poorly understood.</p><p>In this thesis we used an animal model to study biochemical and behavioural effects of chronic AAS treatment (15 mg/kg/day of nandrolone decanoate for 14 days). The effect on the endogenous opioid peptides and the expression of immediate-early gene protein Fos in various brain regions were studied using radioimmunoassay and immunohistochemistry, respectively. In addition, we studied AAS effect on voluntary alcohol consumption and defensive behaviours, including aggression. The results show that AAS enhance endogenous opioid activity and Fos expression in brain regions regulating reward, aggression and disinhibitory behaviours. An imbalance between two opioid systems with generally opposing effects, the enkephalins with euphoric and the dynorphins with dysphoric effects, was also found. This implies that AAS alter the ability to maintain a stable state of mind and the response to other drugs of abuse. The AAS pre-treated animals enhanced their alcohol intake, were more aggressive and showed lower fleeing and freezing reaction than the controls. In addition, AAS enhanced amphetamine-induced aggression when the amphetamine was given three weeks after the last AAS injection.</p><p>The behavioural and biochemical results found in this thesis, support the hypothesis that use of AAS might lead to the development of dependence and may induce changes in the brain leading to disinhibitory behaviours.</p>

<p>The neurosteroids constitute a group of powerful hormones synthesized and acting in the central nervous system. They participate in a number of important central processes, such as memory and learning, mood and neuroprotection. Their effects emerge from rapid interactions with membrane bound receptors, such as the N-methyl-D-aspartate (NMDA) receptor, the gamma-amino-butyric acid receptor and the sigma 1 receptor. The mechanisms of action are separate from classical genomic interactions. </p><p>The aims of this thesis were to identify and characterize the molecular mechanisms underlying the effects of nanomolar concentrations of neurosteroids at the NMDA receptor. </p><p>The results show that the neurosteroids pregnenolone sulfate (PS) and pregnanolone sulfate 3α5βS) differently modulate the NMDA receptor, changing the kinetics for the NMDA receptor antagonist ifenprodil, through unique and separate targets at the NR2B subunit. The effects that appear to be temperature independent were further confirmed in a calcium imagining functional assay. A second functional study demonstrated that PS and 3α5βS affect glutamate-stimulated neurite outgrowth in NG108-15 cells. </p><p>Misuse of anabolic androgenic steroids (AAS) has powerful effects on emotional states. Since neurosteroids regulate processes involved in mood it can be hypothesised that AAS can interact with the action of neurosteroids in the brain. However, chronic administration of the AAS nandrolone decanoate did not alter the allosteric effects of PS or 3α5βS at the NMDA receptor, but changed the affinity for PS, 3α5βS and dehydroepiandrosterone sulfate to the sigma 1 receptor. The results also showed that the neurosteroids displace ³H-ifenprodil from the sigma 1 and 2 receptors without directly sharing the binding site for ³H-ifenprodil at the sigma 1 receptor. The decreased affinity for the neurosteroids at the sigma 1 receptor may be involved in the depressive symptoms associated with AAS misuse.</p><p>The NMDA receptor system is deeply involved in neurodegeneration and the NMDA receptor antagonist ifenprodil exert neuroprotective actions. The findings that neurosteroids interact with ifenprodil at the NMDA receptor may be an opportunity to obtain synergistic effects in neuroprotective treatment.</p>

A new group of anabolic androgenic steroid (AAS) users has developed during the last two decades. This group consists primarily of young men interested in improving their physical appearance. Within this group, AAS are sometimes used together with other illicit drugs, alcohol and nicotine. Brutal and violent crimes have been committed under the influence of AAS, possibly because of AAS psychiatric side effects, ranging from increased aggression and psychosis to depression. Unfortunately, the biochemical mechanisms behind these effects are poorly understood. In this thesis we used an animal model to study biochemical and behavioural effects of chronic AAS treatment (15 mg/kg/day of nandrolone decanoate for 14 days). The effect on the endogenous opioid peptides and the expression of immediate-early gene protein Fos in various brain regions were studied using radioimmunoassay and immunohistochemistry, respectively. In addition, we studied AAS effect on voluntary alcohol consumption and defensive behaviours, including aggression. The results show that AAS enhance endogenous opioid activity and Fos expression in brain regions regulating reward, aggression and disinhibitory behaviours. An imbalance between two opioid systems with generally opposing effects, the enkephalins with euphoric and the dynorphins with dysphoric effects, was also found. This implies that AAS alter the ability to maintain a stable state of mind and the response to other drugs of abuse. The AAS pre-treated animals enhanced their alcohol intake, were more aggressive and showed lower fleeing and freezing reaction than the controls. In addition, AAS enhanced amphetamine-induced aggression when the amphetamine was given three weeks after the last AAS injection. The behavioural and biochemical results found in this thesis, support the hypothesis that use of AAS might lead to the development of dependence and may induce changes in the brain leading to disinhibitory behaviours.

The neurosteroids constitute a group of powerful hormones synthesized and acting in the central nervous system. They participate in a number of important central processes, such as memory and learning, mood and neuroprotection. Their effects emerge from rapid interactions with membrane bound receptors, such as the N-methyl-D-aspartate (NMDA) receptor, the gamma-amino-butyric acid receptor and the sigma 1 receptor. The mechanisms of action are separate from classical genomic interactions. The aims of this thesis were to identify and characterize the molecular mechanisms underlying the effects of nanomolar concentrations of neurosteroids at the NMDA receptor. The results show that the neurosteroids pregnenolone sulfate (PS) and pregnanolone sulfate 3α5βS) differently modulate the NMDA receptor, changing the kinetics for the NMDA receptor antagonist ifenprodil, through unique and separate targets at the NR2B subunit. The effects that appear to be temperature independent were further confirmed in a calcium imagining functional assay. A second functional study demonstrated that PS and 3α5βS affect glutamate-stimulated neurite outgrowth in NG108-15 cells. Misuse of anabolic androgenic steroids (AAS) has powerful effects on emotional states. Since neurosteroids regulate processes involved in mood it can be hypothesised that AAS can interact with the action of neurosteroids in the brain. However, chronic administration of the AAS nandrolone decanoate did not alter the allosteric effects of PS or 3α5βS at the NMDA receptor, but changed the affinity for PS, 3α5βS and dehydroepiandrosterone sulfate to the sigma 1 receptor. The results also showed that the neurosteroids displace 3H-ifenprodil from the sigma 1 and 2 receptors without directly sharing the binding site for 3H-ifenprodil at the sigma 1 receptor. The decreased affinity for the neurosteroids at the sigma 1 receptor may be involved in the depressive symptoms associated with AAS misuse. The NMDA receptor system is deeply involved in neurodegeneration and the NMDA receptor antagonist ifenprodil exert neuroprotective actions. The findings that neurosteroids interact with ifenprodil at the NMDA receptor may be an opportunity to obtain synergistic effects in neuroprotective treatment.

Aromatase is an enzyme that facilitates the conversion of androgens to estrogens and may play a role in mood and mental status. The main theme of this thesis is the imaging of brain aromatase by use of the PET technique. The PET tracer for aromatase, 11C-labeled vorozole (VOZ) was developed and evaluated by with in vitro and in vivo methods. In vitro experiments using rat brain showed that VOZ was distributed in the medial amygdala, bed nucleus of the stria terminalis and medial preoptic area, regions of the brain known to be rich in aromatase and the KD value was determined to be 0.60 nM. The in vivo PET study in rhesus monkey brain revealed that VOZ penetrated the blood-brain barrier and accumulated in the amygdala and hypothalamus. Taken together, VOZ is a good PET tracer for in vivo aromatase imaging with high affinity and high sensitivity. This technique was applied to an investigation of brain aromatase under the physiological conditions simulating anabolic-androgenic steroid abuse. A significant increase in VOZ binding by anabolic-androgenic steroids was observed in the bed nucleus of stria terminalis and medial preoptic area in the rat brain. In contrast, no significant change in binding was observed in the medial amygdala. These results indicate that the manner of regulation of aromatase expression might be different in the bed nucleus of stria terminalis and medial preoptic area compared with that in the medial amygdala. The aromatase expression was suggested to be regulated through androgen receptors, as indicated in a study with flutamide treatment. The increased aromatase expression was seen in neurons. The PET study with anabolic steroid-treated rhesus monkeys also showed increased VOZ binding in the hypothalamus but not in the amygdala. The alteration of density of aromatase binding in the hypothalamic area could explain some psychological features of anabolic-androgenic steroid abusers. Novel PET tracers for aromatase were developed and examined. The two newly synthesized 18F-labeled vorozole analogs, [18F]FVOZ and [18F]FVOO, displayed different characteristics. Both tracers showed similar binding pattern as VOZ; however, [18F]FVOO was metabolized very quickly, meaning that this tracer is not suitable as a PET tracer. On the other hand, [18F]FVOZ can be an appropriate PET tracer. The role of aromatase in the human brain has not been clarified yet. To approach this problem by in vivo methods, we have just started PET studies to explore aromatase expression in humans.