Jiang, Jieying. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 170-186). / Abstract also in Chinese. / ACKNOWLEDGEMENT --- p.II / ABBREVIATIONS --- p.III / ABSTRACT OF THESIS ENTITLED: --- p.VI / 摘要 --- p.IX / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- Individual variations of blood sex steroid levels and their determinants --- p.1 / Chapter 1.1.1 --- Introduction to Sex steroids --- p.1 / Chapter 1.1.2 --- Androgens --- p.1 / Chapter 1.1.2.1 --- Types of androgens --- p.1 / Chapter 1.1.2.2 --- Androgens plasma concentration and relative biological potencies --- p.2 / Chapter 1.1.2.3 --- Androgen biosynthesis and metabolism --- p.3 / Chapter 1.1.2.4 --- Testosterone transportation in plasma --- p.6 / Chapter 1.1.2.5 --- Measurement of free testosterone --- p.7 / Chapter 1.1.2.6 --- The hypothalamus-pituitary-testicular axis and testosterone secretion --- p.8 / Chapter 1.1.2.7 --- Androgen action --- p.10 / Chapter 1.1.2.8 --- Androgen biological function and diseases in men --- p.11 / Chapter 1.1.3 --- Estrogen biological function and diseases in men --- p.12 / Chapter 1.1.4 --- Factors influencing circulating sex steroid levels --- p.13 / Chapter 1.1.4.1 --- Genetic determinants affecting sex steroid levels --- p.15 / Chapter 1.2 --- Genetic variants in sex steroid metabolic pathway and hepatocellular carcinoma (HCC) --- p.18 / Chapter 1.2.1 --- Epidemiology of HCC --- p.18 / Chapter 1.2.2 --- Etiological factors of HCC --- p.22 / Chapter 1.2.3 --- The male predominance in HCC --- p.24 / Chapter 1.2.4 --- Genetic predisposition to HCC --- p.26 / Chapter CHAPTER 2 --- PART A STUDY: GENETIC VARIATIONS IN SEX STEROID METABOLIC PATHWAY AND ASSOCIATION WITH SEX STEROID LEVELS --- p.28 / Chapter 2.1 --- Introduction --- p.28 / Chapter 2.1.1 --- Candidate genes association with sex steroid levels --- p.28 / Chapter 2.1.2 --- Genes involved in androgen metabolism --- p.29 / Chapter 2.1.2.1 --- SRD5A --- p.29 / Chapter 2.1.2.2 --- HSD3B1 --- p.30 / Chapter 2.1.2.3 --- HSD17B2 --- p.31 / Chapter 2.1.2.4 --- AKR1C3 and AKRlC4 --- p.31 / Chapter 2.1.2.5 --- AKR1D1 --- p.32 / Chapter 2.1.3 --- Genes involved in estrogen metabolism --- p.32 / Chapter 2.1.3.1 --- CYP19A1 --- p.32 / Chapter 2.1.3.2 --- Other genes involved in estrogen metabolism --- p.33 / Chapter 2.1.4 --- Association of sex steroid related genes and blood concentrations of sex steroid levels --- p.33 / Chapter 2.1.4.1 --- Genes involved in androgen metabolic pathway and association with sex steroid levels --- p.33 / Chapter 2.1.4.2 --- Genes involved in estrogen metabolic pathway and association with sex steroid levels --- p.36 / Chapter 2.1.5 --- Aims of the study (Part A) --- p.37 / Chapter 2.2 --- Materials and methods --- p.38 / Chapter 2.2.1 --- Study subjects and biological samples --- p.38 / Chapter 2.2.2 --- TagSNP selection --- p.39 / Chapter 2.2.3 --- Genotyping of tagging SNPs --- p.41 / Chapter 2.2.4 --- Genotyping methods comparison --- p.52 / Chapter 2.2.5 --- Statistics --- p.53 / Chapter 2.3 --- Results --- p.54 / Chapter 2.3.1 --- Characteristics of study population --- p.54 / Chapter 2.3.2 --- Replication study for the association of CYP19A1 --- p.55 / Chapter 2.3.2.1 --- Association of the SNP rs2470152 and rs2899470 with serum estrogen and testosterone levels --- p.55 / Chapter 2.3.2.2 --- Halotype analysis and haplotype association in the tertile groups --- p.61 / Chapter 2.3.2.3 --- Haplotype construction of 3 SNPs --- p.63 / Chapter 2.3.3 --- SRD5A1 --- p.65 / Chapter 2.3.3.1 --- Association of SRD5A1 and sex steroid levels --- p.65 / Chapter 2.3.3.2 --- Haplotype analysis and haplotype association in the tertile groups --- p.71 / Chapter 2.3.4 --- SRD5A2 --- p.72 / Chapter 2.3.4.1 --- Association of SRD5A2 and sex steroid levels --- p.72 / Chapter 2.3.4.2 --- Haplotype association analysis of SRD5A2 in tertile groups --- p.76 / Chapter 2.3.5 --- HSD3B1 --- p.77 / Chapter 2.3.5.1 --- Association of HSD3B1 and sex steroid levels --- p.77 / Chapter 2.3.6 --- HSD17B2 --- p.80 / Chapter 2.3.6.1 --- Association of HSD17B2 and sex steroid levels --- p.80 / Chapter 2.3.6.2 --- Halotype association analysis of HSD17B2 in the tertile groups --- p.87 / Chapter 2.3.7 --- AKR1C4 --- p.89 / Chapter 2.3.7.1 --- Association of AKR1C4 and sex steroid levels --- p.89 / Chapter 2.3.7.2 --- Halotype association analysis of AKR1C4 in the tertile groups --- p.93 / Chapter 2.3.8 --- AKR1D1 --- p.94 / Chapter 2.3.8.1 --- Association of AKR1D1 and sex steroid levels --- p.94 / Chapter 2.3.8.2 --- Haplotype association analysis of AKR1D1 in the tertile groups --- p.99 / Chapter 2.3.9 --- AKR1C3 --- p.100 / Chapter 2.3.9.1 --- Association of AKR1C3 and sex steroid levels --- p.100 / Chapter 2.3.9.2 --- Haplotype association analysis of AKR1C3 in the tertile groups --- p.104 / Chapter 2.3.10 --- Overall association of polymorphisms in sex steroid metabolism genes and metabolites levels in blood --- p.105 / Chapter 2.4 --- Discussion --- p.106 / Chapter 2.4.1 --- SRD5A and sex steroid levels --- p.106 / Chapter 2.4.2 --- HSD17B2 and sex steroid levels --- p.110 / Chapter 2.4.3 --- "AKR1D1, AKR1C4, AKR1C3 and catabolic intermediates of sex steroids" --- p.112 / Chapter 2.4.4 --- HSD3B1 and sex steroid levels --- p.114 / Chapter 2.4.4 --- CYP19A1 and sex steroid levels --- p.114 / Chapter CHAPTER 3 --- PART B STUDY: GENETIC VARIATIONS IN SEX STEROID METABOLIC PATHWAY AND ASSOCIATION WITH HCC --- p.119 / Chapter 3.1 --- Introduction --- p.119 / Chapter 3.1.1 --- Previous genetic association studies of HCC on sex steroid metabolic pathways --- p.119 / Chapter 3.1.2 --- Previous genetic association studies of HCC in other pathways --- p.120 / Chapter 3.1.3 --- "Association of sex steroid related genes and other cancers, like prostate cancer" --- p.121 / Chapter 3.1.4 --- Aims of the study (Part B) --- p.123 / Chapter 3.2 --- Materials and method --- p.125 / Chapter 3.2.1 --- "Study subjects, Genomic DNA extraction" --- p.125 / Chapter 3.2.2 --- Tissue specimen and cell lines --- p.125 / Chapter 3.2.3 --- TagSNP selection --- p.126 / Chapter 3.2.4 --- Genotyping of tagging SNPs --- p.126 / Chapter 3.2.5 --- Statistics --- p.127 / Chapter 3.2.6 --- Extraction of RNA and Reverse-Transcription-PCR --- p.128 / Chapter 3.3 --- Results --- p.130 / Chapter 3.3.1 --- SRD5A1 --- p.130 / Chapter 3.3.1.1 --- SRD5A1 polymorphisms and risk of HCC --- p.130 / Chapter 3.3.2 --- SRD5A2 --- p.134 / Chapter 3.3.2.1 --- SRD5A2 polymorphisms and risk of HCC --- p.134 / Chapter 3.3.2.2 --- Haplotype analysis --- p.136 / Chapter 3.3.3 --- HSD3B1 --- p.137 / Chapter 3.3.3.1 --- HSD3B1 polymorphisms and risk of HCC --- p.137 / Chapter 3.3.3.2 --- Haplotype analysis --- p.139 / Chapter 3.3.4 --- HSD17B2 --- p.140 / Chapter 3.3.4.1 --- HSD17B2 polymorphisms and risk of HCC --- p.140 / Chapter 3.3.4.2 --- Haplotype analysis --- p.143 / Chapter 3.3.5 --- CYP19A1 --- p.144 / Chapter 3.3.5.1 --- CYP19A1 polymorphisms and risk of HCC --- p.144 / Chapter 3.3.5.2 --- Haplotype analysis --- p.146 / Chapter 3.3.6 --- AKR1C4 --- p.147 / Chapter 3.3.6.1 --- AKR1C4 polymorphisms and risk of HCC --- p.147 / Chapter 3.3.6.2 --- Haplotype analysis --- p.148 / Chapter 3.3.7 --- AKR1D1 --- p.149 / Chapter 3.3.7.1 --- AKR1D1 polymorphisms and risk of HCC --- p.149 / Chapter 3.3.7.2 --- Haplotype analysis --- p.150 / Chapter 3.3.8 --- AKR1C3 --- p.151 / Chapter 3.3.8.1 --- AKR1C3 polymorphisms and risk of HCC --- p.151 / Chapter 3.3.8.2 --- Haplotype analysis --- p.152 / Chapter 3.3.9 --- mRNA expression study of the 5 α -reductase isoforms --- p.153 / Chapter 3.3.9.1 --- Expression of SRD5A1 and SRD5A2 mRNAin HCC patients --- p.153 / Chapter 3.3.9.2 --- Expression of SRD5A1 and SRD5A2 mRNAin prostate and HCC cell lines --- p.154 / Chapter 3.3.10 --- Overall association of polymorphisms in sex steroid metabolism genes and risk of HCC --- p.154 / Chapter 3.3.11 --- GMDR analysis --- p.156 / Chapter 3.4 --- Discussion --- p.159 / Chapter 3.4.1 --- 5 α-reductase and risk of HCC --- p.159 / Chapter 3.4.1.1 --- SRD5A2 --- p.160 / Chapter 3.4.1.2 --- SRD5A1 --- p.161 / Chapter 3.4.2 --- Other genes and association with HCC --- p.162 / Chapter 3.4.2.1 --- HSD17B2 and risk of HCC --- p.162 / Chapter 3.4.2.2 --- "HSD3B1, AKR1C3, AKR1C4, AKR1D1 and risk of HCC" --- p.163 / Chapter 3.4.2.3 --- CYP19A1 and risk of HCC --- p.164 / Chapter 3.4.3 --- Gene-Gene interactions associated with HCC --- p.165 / Chapter CHAPTER 4 --- CONCLUSIONS AND PROSPECT FOR FUTURE WORK --- p.166 / Chapter 4.1 --- Conclusion --- p.166 / Chapter 4.2 --- Future works and prospect --- p.169 / REFERENCES --- p.170

Thesis (M.Sc.)--Memorial University of Newfoundland, Faculty of Medicine, 1999. / Bibliography: leaves 98-114.

Eteriniai aliejai plačiai naudojami aromaterapijoje, kosmetologijoje, farmacijoje bei parfumerijoje. Nors plačiai kalbama apie eterinių aliejų įtaką žmogui ir jų panaudojimą, tačiau moksliniais tyrimais patvirtintų duomenų apie jų poveikį nėra daug. Šio magistrinio darbo tikslas - ištirti levandų eterinių aliejų poveikį kognityvinėms funkcijoms ir širdies ritmui. Eksperimentai buvo atliekami su 19-25 metų amžiaus vyrais ir moterimis. Moterys buvo tiriamos folikulinės, ovuliacinės, geltonkūnio ir vėlyvosios geltonkūnio mėnesinių ciklo fazių metu, o vyrai – vieno eksperimento metu kvėpavo levandų eteriniu aliejumi, kito – vandeniu. Kiekvieno eksperimento metu prieš ir po kvėpavimo levandų eteriniu aliejumi buvo atliekami kognityviniai (trumpalaikės regimosios atminties, dėmesio ir reakcijos laiko) testai bei nenutrūkstamai registruojama elektrokardiograma. Naudojant Eysenck‘o testą buvo įvertintas tiriamųjų intraversijos - ekstraversijos ir neurotiškumo - emocinio stabilumo asmenybės bruožų išreikštumas. Gauta, kad: 1. Neskirstant tiriamųjų į grupes negautas reikšmingas kvėpavimo levandų eteriniu aliejumi poveikis reakcijos laikui, trumpalaikei regimajai atminčiai, dėmesio parametrams – protino produktyvumo koeficientui, regimosios informacijos apimčiai, informacijos apdorojimo greičiui bei širdies ritmui. 2. Dėmesio tikslumo koeficientas po kvėpavimo eteriniu aliejumi statistiškai patikimai geresnis nei prieš kvėpavimą, kai tiriamieji neskirstomi į grupes. Vyrams šis... [toliau žr. visą tekstą] / Essential oils are mostly used in aromatherapy, cosmetics, pharmacology and in perfumes industry. Though there are wide discussions about influence of essential oils on the human organism, there are not many scientific studies on the influence of these oils and mechanisms of their action. The main purpose of Master thesis is to investigate influence of lavender essential oil on cognitive functions and heart rate. The experiments were conducted with 19 -25 years old males and females. Women were examined in the follicular, ovulation, luteal and late luteal phases of menstrual cycle. Men were examined twice – with essential oil and water (as control). During every experiment before and after inhalation of the lavender essential oil cognitive tests (short-term memory, attention and reaction time) were performed and electrocardiogram was continuously recorded. The personality traits were identified using Eysenck test and subjects were categorized as introvert-extravert and neurotic-emotionally stabile. The main findings are as follows: 1. There was no statistically significant effect of lavender essential oil on reaction time, short term memory, parameters of attention - coefficient of mental productivity, capacity of visual information, velocity of information processing and heart rate when subjects were not subdivided into groups. 2. Coefficient of accuracy increased statistically significantly after breathing with lavender essential oil when subjects were not subdivided into... [to full text]

Disease-specific compounds (biomarkers) are analyzed in clinical laboratories to assist with diagnosing diseases. This thesis describes development and validation of liquid chromatography tandem mass spectrometry (LC-MS/MS) based tests for diagnosing a diverse group of endocrine and metabolic diseases. The analytical methods used on-line and off-line sample extraction and analytical derivatization as means of enhancing the analytical sensitivity, specificity and clinical utility. All developed methods were extensively validated and reference intervals for the biomarker concentrations were established in blood samples of healthy adults and children. Advantages of the LC-MS/MS as an analytical technique include possibility of simultaneous measurement of multiple analytes and ability of confirming their identity. In this thesis we proposed and evaluated approaches for the assessment of the specificity of analysis in the methods that use tandem mass spectrometry detection. To enhance throughput of the LC-MS/MS tests for the biomarkers that have endogenous or exogenous isomers an approach was developed for quantitation of isomers from unresolved chromatographic peaks. Using methods developed in this thesis we performed a study of the steroidogenesis in ovarian follicles of healthy women and women with polycystic ovary syndrome (PCOS). Obtained data on the steroid concentrations and associations between the steroid metabolites in the pathway would be helpful for better understanding of the ovarian pathophysiology. Potential biomarkers of PCOS were identified in the thesis; further studies will be necessary to confirm their clinical utility.

INTRODUÇÃO: A insuficiência cardíaca (IC) é uma síndrome sistêmica, cuja uma das possíveis evoluções se caracteriza pela perda de massa magra e intolerância aos esforços, quadro conhecido como caquexia cardíaca (CC). Estudos realizados usando homens e ratos demonstram que na associação da IC com hipogonadismo há um pior quadro clínico e desenvolvimento de CC, levando a um mal prognóstico e aumento da mortalidade. Para o sexo feminino, tanto no período pré ou pós-menopausa, não é conhecida a associação de possível deficiência de hormônios sexuais, tampouco seu impacto no prognóstico, mortalidade e desenvolvimento de CC em pacientes com IC. Os objetivos deste estudo foram: 1) Avaliar o efeito da IC sobre o possível desenvolvimento de CC em ratas. 2) Avaliar o efeito da IC sobre a produção de hormônios sexuais: Testosterona total, estradiol, FSH. MÉTODOS: Ratas da linhagem Sprague Dawley, com 60 dias de vida, foram divididas de acordo com os procedimentos cirúrgicos: Ratas intactas (INT) ou com ooforectomia (OVX), ratas com cirurgia fictícia (SHAM) do infarto do miocárdio (IM) ou cirurgia IM. A combinação destes procedimentos originou quatro grupos experimentais: INT+SHAM, INT+IM, OVX+SHAM e OVX+IM. Trinta dias após a OVX, amostras de sangue foram coletadas, para a dosagem hormonal e os animais foram submetidos à cirurgia de indução ao IM ou SHAM. Após oitos semanas, as ratas passaram pela avaliação ecocardiográfica. A partir desta, estabeleceu-se um corte de Fração de Ejeção (FE) <= 50% para definir o desenvolvimento de disfunção cardíaca a partir da realização do IM, constituindo dessa forma, os grupos INT+IM e OVX+IM. Com quatro semanas adicionais (totalizando 12 semanas após a indução do IM), houve a consolidação do quadro crônico de IC; então as ratas foram submetidas à avaliação hemodinâmica, da capacidade funcional e a nova coleta de sangue para dosagem hormonal. Após a eutanásia, os tecidos foram coletados para as análises morfológicas e histológicas. RESULTADOS: As ratas dos grupos OVX (OVX+SHAM e OVX+IM) não apresentaram ciclos ovarianos, demonstraram hipertrofia dos úteros e aumento do peso corporal final quando comparadas aos grupos INT (INT+SHAM e INT+IM), além de alterações na morfologia das glândulas adrenais - caracterizando o quadro de privação de hormônios ovarianos. As ratas dos grupos IM (INT+IM e OVX+IM) não tiveram alterações hemodinâmicas, contudo demonstraram reduzida capacidade funcional e piora nas variáveis ecocardiográficas (FE, FS, DSVE, TCIV) quando comparadas aos grupos SHAM (INT+SHAM e OVX+SHAM); as avaliações histológicas apontam valores de área infartada entorno de 40% e hipertrofia de septo nos grupos IM. Os animais não caracterizaram quadro de CC - caracterizada por diminuição do peso corporal, diminuição da densidade capilar na musculatura e atrofia das fibras musculares (m. sóleo) - após12 semanas de disfunção cardíaca / Introduction: Heart failure (HF) is a systemic disease, which one of the possible progress is characterized by lean mass loss and intolerance to efforts, this framework is known as cardiac cachexia (CC). Studies in men and rats have shown that when HF is associated with hypogonadism it has a worse clinical condition and CC evolution, leading to a poor prognosis and increased mortality. For females, both in the pre menopause period than in the post menopause it is not known how the association of sex hormones deficiency with HF can impact the prognosis and mortality of female patients, as well as the development of CC. The objectives of this study were: 1) Evaluate the effect of HF on the possible CC development in female rats. 2) Evaluate the effect of HF on the production of sex hormones: Total testosterone, estradiol, FSH. METHODS: Female rats (Sprague Dawley strain, 60 days old) were divided according to the surgical procedures: intact rats (INT) or ovariectomy (OVX) rats with sham surgery (SHAM) of myocardial infarction (MI) or MI surgery. The combination of these procedures led to four groups: INT + SHAM, INT + MI, OVX + SHAM and OVX + MI. 30 days after OVX, blood samples were collected for hormone dosage and the animals have been underwent to surgery to the MI induction or SHAM. After eight weeks, the rats have gone through echocardiographic evaluation. From this procedure, it was established a cutting Ejection Fraction (EF) <= 50% to define the development of cardiac dysfunction from the realization of MI, constituting INT + IM and IM + OVX groups. With four additional weeks (totaling 12 weeks after MI induction), there was the consolidation of HF\'s chronic condition; female rats were subjected to evaluation of functional and hemodynamic capacity and a new blood collection for hormonal dosage. After euthanasia, tissues were collected for morphological and histological analyzes. RESULTS: The rats of the OVX groups (OVX + SHAM and OVX + MI) showed no ovarian cycles, demonstrated uterus\' hypertrophy and an increase in final body weight when compared to INT groups (INT + SHAM and INT + MI), changes in morphology of the adrenal glands - evidencing the situation of ovarian hormones deprivation. The rats of the MI group (INT + MI and OVX + MI) had no hemodynamic changes, but showed reduced functional capacity and deterioration of echocardiographic variables (EF, FS, LVSD, IVCT) when compared to SHAM groups (INT + SHAM and OVX + SHAM ); the histological evaluations indicate infarcted area values around 40% and septal hypertrophy at MI groups. The animals did not characterize CC - characterized by decreased body weight, decreased capillary density in the muscle and muscle fiber atrophy (m. soleus) - even after 12 weeks of cardiac dysfunction

Les mâles sexuellement expérimentés présentent des modifications à long terme de l'arborisation dendritique, de modifications épigénétiques ainsi qu'une augmentation des niveaux d'expression de protéines associées à la neurotransmission glutamatergique et à la microglie dans l'aire pré-optique médiane (mPOA). En revanche, les concentrations plasmatiques et hypothalamiques en hormones stéroïdes ainsi que les propriétés du système nitrergique, connues pour être modulés par l'expérience sexuelle chez le rat, ne sont pas modifiées. Dans un second temps, l'implication de la voie de signalisation ERK1/2 dans la réponse comportementale associée à l'expérience sexuelle a été étudiée. Nous avons montré que cette voie de signalisation, activée dans la mPOA lors de l'accouplement, est potentialisée par l'expérience sexuelle. Nous avons ensuite démontré que son activation est possible par une action rapide (30 minutes) des stéroïdes. Enfin, nous avons montré que l'inhibition de la voie ERK1/2 avant un premier accouplement n'altère pas la mise en place de l'expérience sexuelle mais diminue de façon réversible la motivation sexuelle des mâles. Ainsi, l'expérience sexuelle est à l'origine de modifications structurales et biochimiques à long terme de la mPOA. Ces modifications, différentes de celles connues chez le rat, sont associées à une potentialisation de la voie de signalisation ERK1/2 activée de façon transitoires durant l'accouplement. Ces résultats mettent en évidence la nécessité d'élaborer un nouveau modèle, différent de celui établi chez le rat, permettant d'expliquer l'amélioration comportementale associée à l'expérience sexuelle chez la souris mâle. / Sexually experimented males exhibit long term modifications of the dendritic arborization, epigenetic modifications and increased levels of microglia and glutamate associated protein within the hypothalamic medial preoptic area (mPOA). However, hypothalamic and plasmatic concentration of steroid hormones and the nitrergic system are not impacted, contrary to data obtained in rat.The involvement of the ERK1/2 signaling pathway in the induction of sexual experience has also been studied. We showed that ERK1/2 pathway was activated within the mPOA during mating. This activation was increased in sexually experienced males. Furthermore, we showed ex vivo on hypothalamic slices that sex steroids were capable of rapidly (30 min) activate this pathway. Finally, the inhibition of ERK1/2 phosphorylation before the first mating did not disrupt the induction of sexual experience but decreased sexual motivation in a reversible manner.Taken together, these results indicate that long lasting and transitory plasticity mechanisms leading to sexual experience are different between rat and mouse. This indicate the necessity to elaborate a new molecular model associated with the behavioral improvement induced by sexual experience in male mouse.

Dehydroepiandrosterone, a C-19 steroid, is found endogenously with the highest circulating serum levels. It is converted to important steroids such as the sex hormones oestrogen and testosterone. DHEA has come under the spotlight as a purported “fountain of youth” due to its well-characterised age-related decline. The supplementation of DHEA in both the elderly and those with a pathophysiological deficiency has been shown to be of benefit, particularly with regard to wellbeing and depression. The role of DHEA in the periphery has not been elucidated beyond its role as a precursor hormone in sex steroid biosynthesis, though it has been established as a neuroactive neurosteroid, capable of exerting neuroprotective effects in the brain. Since the importance of free radicals in aging and neurodegeneration is well established, investigations were conducted on the ability of DHEA to inhibit free radical generation or scavenge existing free radicals. DHEA was able to significantly inhibit quinolinic acid-induced lipid peroxidation, a measure of membrane damage, over a range of concentrations, although the reduction did not appear to be dose-dependent. This was observed in both in vitro and in vivo studies. Thus, the ability of a compound to reduce the degree of lipid peroxidation may indicate its value as a neuroprotectant. However, DHEA did not significantly reduce cyanide induced generation of the superoxide free radical, suggesting that DHEA is not an effective free radical scavenger of the superoxide anion and that the reduction in lipid peroxidation does not occur through a scavenging mechanism. Apoptosis is a physiological process which is necessary for development and homeostasis. However, this form of programmed cell death can be initiated through various mechanisms and too much apoptotic cell death results in deleterious effects in the body. DHEA was shown not to induce apoptosis. Even the lowest concentration of DHEA investigated in this thesis shows a remarkable decrease in the degree of apoptosis caused by intrahippocampal chemical insult by the neurotoxin quinolinic acid. Cresyl violet was used to visualise tissue for histological examination which revealed that DHEA is able to preserve the normal healthy morphology of hippocampal cells which have been exposed to quinolinic acid. Cells maintained their integrity and showed little evidence of swelling associated with necrosis. Organ culture studies were performed by assessing the impact of DHEA on several pineal metabolites. The study revealed that DHEA exerted an effect on the metabolism of indoleamines in the pineal gland. Melatonin, the chief pineal hormone, did not appear to be affected while the concentrations of N-acetylserotonin, serotonin and methoxytryptamine showed significant alterations. Thus, the neuroprotective mechanism of DHEA does not appear to be mediated by an increase in the presence of melatonin. The biological importance of metal ions in neurodegeneration is also well established and thus the potential interaction between DHEA and metal ions was considered as a mechanism of action. Spectroscopic and electrochemical analyses were performed to determine whether DHEA is able to interact with metal ions as a ligand. These reveal that DHEA does not form a strong bond with the metals investigated, namely copper (II) and iron (III), but that a weak interaction is evident. These investigations were conducted in a rodent model, which has neither large amounts of endogenous DHEA, nor the enzymatic infrastructure present in humans. Thus, the theory that DHEA exerts its effects through downstream metabolic products is unlikely. However, these investigations reveal that there is merit in the statement that DHEA itself is a neuroprotective molecule, and confirm that the further investigation of DHEA is an advisable strategy in the war against neurodegeneration and aging.

L’intégrité fonctionnelle de la barrière hémato-encéphalique (BHE) est altérée dans de nombreuses pathologies neurologiques et métaboliques. Les vaisseaux cérébraux sont des tissus cibles des hormones stéroïdes sexuelles mais la contribution respective de ces effecteurs endocriniens et de leurs récepteurs dans l’intégrité de la BHE reste encore à être précisée. Les effets des hormones gonadiques sur l’unité neurovasculaire chez la souris ont été étudiés, en se concentrant sur l’aire préoptique médiane de l’hypothalamus, une région cérébrale hormono-sensible. L’augmentation de la perméabilité de la BHE chez des souris mâles et femelles gonadectomisés. Elle est associée chez le mâle à une désorganisation des jonctions serrées et une diminution de l’expression des protéines les constituant, à une activation des cellules gliales, et à une augmentation de l’expression de molécules inflammatoires, la supplémentation en testostérone permettant la restoration. Les récepteurs des androgènes et des estrogènes peuvent ainsi être impliqués dans la régulation hormono-dépendante du transport paracellulaire. La lignée de souris transgéniques sélectivement invalidées pour le récepteur neural des androgènes, a permis de mettre en évidence l’effet délétère de l’absence de ce récepteur sur l’intégrité de la BHE et des jonctions serrées. Pour compléter, un modèle ex vivo de tranches d’hypothalamus a permis d’appréhender les effets à court terme de la testostérone sur la BHE. Ces données soulèvent des questions sur les effets délétères potentiels des perturbateurs endo-criniens sur l'intégrité BBB et l'apparition de maladies neurologiques et métaboliques associées. / Functional integrity of the blood-brain barrier (BBB) is compromised in many neurological and metabolic pathologies. Cerebral blood vessels are target tissue for sex steroid hormones but the relative contribution of these endocrine effectors and their receptors in the BBB integrity are still unclear. Effects of gonadal hormones on the mouse neurovascular unit were studied, focusing on the hypothalamic medial preoptic area, a highly sensitive brain area to gonadal steroid hormones. BBB permeability increased in both gonactectomized male and female, is associated with tight junction disorganization and lower expression of tight junction proteins, glial activation, and up-regulation of inflammatory molecules in male. Testosterone supplementation restores the BBB impermeability, tight junction integrity, and almost completely abrogated the inflammatory features. Androgen and estrogen receptor may be involved in testosterone-induced regulation of the formation and maintenance of tight junction in males. Studying the involvement of these receptors using a trans-genic mice line selectively lacking neural AR in the CNS, highlighted the negative effect of this dele-tion on the BBB and TJ integrity. To complete, ex vivo slices of male mouse hypothalamus allowed to assess short-term molecular mechanisms of testosterone on the BBB structure and function.These data raise questions about the potential deleterious effects of endocrine disruptors on the BBB integrity and the occurrence of neurological and metabolic diseases.

A matriz extracelular (MEC) dos tecidos uterinos é altamente remodelada na gestação de camundongos. Os objetivos deste estudo foram avaliar a influência dos hormônios ovarianos estrógeno (E2) e progesterona (P4) sobre a estrutura dos tecidos uterinos de camundongo e a deposição dos proteoglicanos decorim, biglicam, fibromodulim, lumicam, perlecam e versicam nestes tecidos. Para isto, utilizamos um modelo de castração e reposição hormonal, e o ciclo estral como parâmetro fisiológico. Verificamos que, como na gestação, durante o ciclo estral ocorre intensa remodelação na estrutura e na MEC dos tecidos uterinos. Verificamos ainda que a resposta aos hormônios ovarianos é: compartimento-específica; hormônio-específica e molécula-específica. Notável foi a modulação do versicam pelos hormônios ovarianos. P4 induz a deposição de versicam no estroma, enquanto o miométrio responde apenas a E2. A modulação dos proteoglicanos pelos hormônios ovarianos mostra a relevância destas moléculas para a composição de um ambiente uterino propício para o desenvolvimento do embrião. / The extracellular matrix (ECM) of the mouse uterine tissues is highly remodeled during pregnancy. The aim of this study was to demonstrate the influence of estrogen (E2) and progesterone (P4) on the uterine structure and on the deposition of the proteoglycans decorin, biglycan, fibromodulin, lumican, perlecan and versican in these tissues. For that purpose, we used a model of castration e hormone replacement as main strategy, and the estrous cycle as physiological parameter. We verified that, as in pregnancy, during the estrous cycle an intense remodeling occurs on the structure and the ECM of the uterine tissues. We also showed that the response to the ovarian hormones is: compartment-; hormone- and molecule- specific. Noteworthy was the modulation of versican by the hormones: P4 induces the deposition of versican in the stroma, whereas the myometrium responds only to E2. The modulation of proteoglycans by the ovarian hormones indicates the relevance of these molecules for the composition of a proper microenvironment for embryo development.

Currently there is a spate of interest in the presence of pharmacologically active substances in the environment. These substances are excreted in active or metabolized form and with wastewater pass the wastewater treatment plant. Current treatment technologies do not always eliminate all pharmaceuticals effectively and therefore they enter the environment. One of these active groups is the group of steroid hormones. Steroid hormones belong to the group of endocrine disruptors and they are considered to be dangerous for the ecosystems. Due to the hydrophobic character of steroid hormones they undergo partial or total sorption from wastewater to sludge. Sewage sludge is the by product of wastewater treatment and contains heavy metals, organic contaminants and pathogenic bacteria. A part of produced sewage sludge is used as a fertilizer in the Czech Republic. This issue follows the regulation 347/2016 – conditions of agricultural use of sewage sludge. Waste policy of EU will alter the conditions of sludge disposal, so it is necessary to obtain data about the concentration levels, fate and behaviour of those pollutants. This thesis was focused on five natural female hormones and four synthetic, which are used as a part of contraceptive pills and substitutional hormonal therapy. Determination of hormones was performed in four steps including ultrasonic assisted extraction, clean up by solid phase extraction, derivatization and final analysis by gas chromatography with mass spectrometry on triple quadrupole in MS/MS mode.