O Pseudohermafroditismo masculino disgenético (Anomalia da diferenciação sexual 46,XY ADS 46,XY) é definido como ambigüidade genital num paciente com testículos e/ou cariótipo 46,XY com uma das seguintes características: alteração histológica testicular, ausência ou hipoplasia das células de Leydig em tecido previamente estimulado com gonadotrofina coriônica humana(hCG), falta de resposta de testosterona ao estímulo com hCG sem acúmulo de precursores, ausência de células germinativas, presença de derivados müllerianos indicando inadequada produção do hormônio antiMülleriano (HAM) ou resistência de seus receptores. Esse estudo apresenta uma avaliação clínica, laboratorial, anátomopatológica, morfométrica e molecular de 10 pacientes com ADS 46,XY; dois pacientes apresentaram mutação no SF1 (fator esteroidogênico 1), duas mutações no domínio hingee uma terceira produziu um stop códon na posição 404; três pacientes com deleção da cópia do DAZ2. A morfometria testicular mostrou todos os diâmetros tubulares médios (DTM) moderado a gravemente diminuídos e os índices de fertilidade tubular leve a moderadamente diminuídos. Devido à dificuldade do diagnóstico diferencial e etiológico, o estudo morfométrico e molecular deve sempre acompanhar esses casos de ADS 46,XY. / The dysgenetic male pseudohermaphroditism 46,XY ; disorders of sex development (DSD 46,XY) is defined as sexual ambiguity in patients with testis and/or 46,XY karyotype and one of the characteristics: hystologic alteration of the testis; absence or hypoplasia of Leydig cells; a decreased testosterone response to human chorionic gonadotropin stimulation without accumulation of testosterone precursors; absent germ cells; presence of müllerian duct derivatives showing inappropriate production of antimüllerian hormone (AMH) or resistance to its receptors. This study shows the clinic, laboratory, histologic, morphometric and molecular evaluation of 10 patients with DSD 46,XY; two patients showed mutations in the SF1 gene (steroidogenic factor-1); two in the hinge domain and one stop codon at the position 404 of the protein; three patients exhibited deletion of DAZ2. The testis morphometry showed reduction: marked to severe of all mean tubular diameter (MTD) while the reduction of the tubular fertility index (TFI) were slight to marked. Due to difficulties establishing the differential diagnosis and the etiology, the morphometric and molecular evaluation must be always done in the patients with DSD 46,XY.

O Pseudohermafroditismo masculino disgenético (Anomalia da diferenciação sexual 46,XY ADS 46,XY) é definido como ambigüidade genital num paciente com testículos e/ou cariótipo 46,XY com uma das seguintes características: alteração histológica testicular, ausência ou hipoplasia das células de Leydig em tecido previamente estimulado com gonadotrofina coriônica humana(hCG), falta de resposta de testosterona ao estímulo com hCG sem acúmulo de precursores, ausência de células germinativas, presença de derivados müllerianos indicando inadequada produção do hormônio antiMülleriano (HAM) ou resistência de seus receptores. Esse estudo apresenta uma avaliação clínica, laboratorial, anátomopatológica, morfométrica e molecular de 10 pacientes com ADS 46,XY; dois pacientes apresentaram mutação no SF1 (fator esteroidogênico 1), duas mutações no domínio hingee uma terceira produziu um stop códon na posição 404; três pacientes com deleção da cópia do DAZ2. A morfometria testicular mostrou todos os diâmetros tubulares médios (DTM) moderado a gravemente diminuídos e os índices de fertilidade tubular leve a moderadamente diminuídos. Devido à dificuldade do diagnóstico diferencial e etiológico, o estudo morfométrico e molecular deve sempre acompanhar esses casos de ADS 46,XY. / The dysgenetic male pseudohermaphroditism 46,XY ; disorders of sex development (DSD 46,XY) is defined as sexual ambiguity in patients with testis and/or 46,XY karyotype and one of the characteristics: hystologic alteration of the testis; absence or hypoplasia of Leydig cells; a decreased testosterone response to human chorionic gonadotropin stimulation without accumulation of testosterone precursors; absent germ cells; presence of müllerian duct derivatives showing inappropriate production of antimüllerian hormone (AMH) or resistance to its receptors. This study shows the clinic, laboratory, histologic, morphometric and molecular evaluation of 10 patients with DSD 46,XY; two patients showed mutations in the SF1 gene (steroidogenic factor-1); two in the hinge domain and one stop codon at the position 404 of the protein; three patients exhibited deletion of DAZ2. The testis morphometry showed reduction: marked to severe of all mean tubular diameter (MTD) while the reduction of the tubular fertility index (TFI) were slight to marked. Due to difficulties establishing the differential diagnosis and the etiology, the morphometric and molecular evaluation must be always done in the patients with DSD 46,XY.

Made available in DSpace on 2015-03-26T13:02:53Z (GMT). No. of bitstreams: 1 texto completo.pdf: 993981 bytes, checksum: 6248f33efc521385bbe0151f2cb62419 (MD5) Previous issue date: 2009-02-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In comparison to mammals of the family Cervidae from other continents, the South American cervids are the most understudied. Moreover, approaches aiming to establish the reproductive biology of neotropical cervids are scarce. In this way, the objective of this study was to characterize morphologically and morphometrically the testis of the brown brocket deer (Mazama gouazoubira), providing information to improve the understanding of the reproductive biology of this species. For that, we have used seven adult male brown brocket deers, kept in captivity. Testicular fragments were obtained by testicular biopsy incision. The average body weight of brown brocket deer was 17.14kg, from which 0.40% were allocated in gonads and 0.33% in seminiferous tubules, which represented 85.86% of the testis parenchyma. The brown brocket deer presented high percentage of corporal mass allocated to testes and seminiferous tubules, exhibiting the greatest values described for most of studied mammalian species. The calculated volume of albuginea of right and left testis was 3.52mL, representing 5.33% of the testis mass. The volume of both mediastina was 1g, corresponding to 1.53% of testis mass. Therefore, the testicular parenchyma corresponds to 93.14% of the testis in brown brocket deers, making up a volume of 64.88mL. The average diameter of seminiferous tubules was 224.43µm and the average thickness of the seminiferous epithelium was 69.58µm. The brown brocket deer has around 1418m of seminiferous tubules in both testes, or an average of 21.47m of seminiferous tubules per gram of testis. The testicular parenchyma in the brown brocket deer was composed of 4.48% of Leydig cells, 4.41% of connective tissue, 2.89% of lymphatic vessels, and 2.36% of blood vessels. The Leydig cells occurred in groups of varied number of cells, with no particular pattern of distribution, and were observed around blood vessels, near to lymph vessels or associated with the lamina propria of seminiferous tubules. The average volume of Leydig cells was 677.52μm3 and their average nuclear diameter was 7.18µm. The average nuclear volume of Leydig cells was 194.33µm3. The nuclei of Leydig cells corresponded, in average, to 29.01% of total cell volume. The average total volume of Leydig cells in both testes was 2.90mL. The Leydigosomatic index was 0.0084% and the total number of Leydig cells per gram of testis was more than 60 millions. This number of Leydig cells per gram of testis is higher than that reported for most mammals studied. The organizational pattern of the testicular parenchyma of the brown brocket deers used in this study was similar to that described for most studied mammalian species, although with specific variations in the proportion and volume of some elements of the testicular parenchyma. Regarding the intertubular compartment, the organizational pattern of the elements of this region was in accordance with the standard type II, described by Fawcett, but presented variations in the connective tissue, which was slightly swollen. The qualitative and quantitative description of testicular histology of Brown brocket deer help to understand its spermatogenic process, and to establish parameters of the reproductive biology of this wild species. Furthermore, the preliminary data presented in this study could help subsequent research using other species of Brazilian cervids, especially those endangered, making possible the preservation of those species. / Em comparação com os mamíferos da família Cervidae de outros continentes, os cervídeos da América do Sul são os menos estudados. São escassas as pesquisas com a finalidade de estabelecer parâmetros para a biologia reprodutiva dos cervídeos neotropicais. Neste sentido, o objetivo deste trabalho foi caracterizar morfológica e morfometricamente o testículo do veado-catingueiro (Mazama gouazoubira), fornecendo informações que permitam compreender os aspectos básicos da biologia reprodutiva desta espécie. Foram utilizados sete veados-catingueiros adultos mantidos em cativeiro. Os fragmentos testiculares foram obtidos por meio de biópsia testicular incisional. O peso corporal médio dos veados-catingueiros foi de 17,14kg dos quais 0,40% estão alocados em gônada e 0,33% em túbulos seminíferos que representaram 85,86% do parênquima testicular. O veado-catingueiro apresentou um alto percentual de massa corporal alocada em testículo e túbulos seminíferos, enquadrando-se entre os maiores valores descritos para a maioria dos mamíferos estudados. Os volumes calculados para as albugíneas dos testículos direito e esquerdo foram de 3,52mL, representando 5,33% da massa testicular. O volume do mediastino em ambos os testículos foi de 1g, representando 1,53% da massa dos testículos. Portanto, o parênquima testicular ocupa, em veados-catingueiros adultos, 93,14% do testículo, perfazendo um volume de 64,88mL. O diâmetro médio dos túbulos seminíferos foi de 224,43µm e a espessura média do epitélio seminífero foi de 69,58µm. O veado-catingueiro apresenta em torno de 1418 metros de túbulos seminíferos em ambos os testículos, perfazendo uma média de 21,47 metros de túbulos seminíferos por grama de testículo. A organização do parênquima testicular de veados- catingueiros adultos é semelhante ao padrão descrito para os mamíferos, porém com variações específicas quanto à proporção e volumetria dos elementos do parênquima testicular. No veado-catingueiro, 4,48% do parênquima testicular é ocupado por células de Leydig, 4,41% por tecido conjuntivo, 2,89% por vasos linfáticos e 2,36% por vasos sanguíneos. As células de Leydig ocorrem em grupos de tamanhos variados não apresentando padrão de distribuição definido, podendo ser observadas ao redor dos vasos sanguíneos, próximas aos vasos linfáticos ou associadas com a lâmina própria dos túbulos seminíferos. O volume médio das células de Leydig foi de 677,52µm3 e o seu diâmetro nuclear médio foi de 7,18µm. O volume nuclear médio da célula de Leydig foi de 194,33μm3. O núcleo da célula de Leydig correspondeu, em média, a 29,01% do seu volume total. O volume médio total das células de Leydig em ambos os testículos foi de 2,90mL. O índice Leydigossomático foi de 0,0084% e o número total de células de Leydig por grama de testículo foi superior a 60 milhões. O número de células de Leydig por grama de testículo foi superior ao relatado para a maioria dos mamíferos já estudados. O intertúbulo de veado- catingueiro apresenta população celular semelhante ao descrito para mamíferos. O padrão de organização dos elementos do compartimento intertubular se enquadra no padrão tipo II descrito por Fawcett, mostrando tecido conjuntivo frouxo pouco edemaciado. A descrição e quantificação histológica testicular realizadas neste estudo auxiliam na compreensão dos padrões espermatogênicos desta espécie, estabelecendo parâmetros da sua biologia reprodutiva básica. Além disso, esses conhecimentos preliminares podem subsidiar trabalhos subseqüentes com outras espécies de cervídeos existentes no Brasil, especialmente as ameaçadas de extinção, possibilitando a obtenção de dados importantes para a conservação das mesmas.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-06-20T20:06:17Z No. of bitstreams: 1 leonardotoshiooshio.pdf: 6184732 bytes, checksum: 2ae5dded31a5fbae3336c3f4555afe20 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-07-13T15:26:54Z (GMT) No. of bitstreams: 1 leonardotoshiooshio.pdf: 6184732 bytes, checksum: 2ae5dded31a5fbae3336c3f4555afe20 (MD5) / Made available in DSpace on 2016-07-13T15:26:54Z (GMT). No. of bitstreams: 1 leonardotoshiooshio.pdf: 6184732 bytes, checksum: 2ae5dded31a5fbae3336c3f4555afe20 (MD5) Previous issue date: 2012-08-31 / O Extrato de Ginkgo biloba (EGb) é um dos fitoterápicos mais consumidos no mundo e tem sido utilizado no tratamento da disfunção erétil e como afrodisíaco. O presente trabalho teve como objetivo avaliar a toxicidade sistêmica do EGb e o efeito sobre o sistema reprodutor masculino de ratos Wistar. Oitenta animais de três meses de idade foram tratados com água destilada (Grupo Controle) e extrato aquoso de Ginkgo biloba nas seguintes doses: 3,5 (EGb 3,5); 7,0 (EGb 7,0) e 14,0 mg/kg (EGb 14,0) uma vez ao dia, por 56 dias consecutivos. Foram avaliados o peso corporal, estimativa de consumo diário de ração, indícios de sinais clínicos de toxicidade, peso de órgãos e glândulas acessórias do sistema reprodutor masculino e dados histométricos testiculares. Espermatozoides foram coletados da cauda do epidídimo e foram submetidos à contagem e avaliados quanto à vitalidade e morfologia. Foram realizados hemograma completo, dosagem bioquímica sérica de ureia, creatinina e alanina aminotransferase (ALT) e concentração de testosterona total sérica. Não foram observados nos animais sinais clínicos de toxicidade sistêmica e mortes. Apesar de ter ocorrido diferenças estatísticas significativas na estimativa de consumo de ração, hemoglobinometria, concentração de hemoglobina globular média e volume das células de Leydig, concluise que o EGb no presente trabalho, e com as doses utilizadas, não causou toxicidade sistêmica nem promoveu alteração na morfometria testicular e qualidade espermática de ratos Wistar. / Ginkgo biloba Extract (GBE) is one of the most consumed herbal medicines in the world and it has been used in the treatment of erectile dysfunction and as an aphrodisiac. The present study had as objective to evaluate the GBE systemic toxicity and its effect on male reproductive system of Wistar rats. Eighty animals of threemonth- old age were treated with distilled water (Control Group) and aqueous extract of Ginkgo biloba in the following doses: 3.5 (GBE 3.5); 7.0 (GBE 7.0) and 14.0 mg/kg (GBE 14.0) once per day, for 56 consecutive days. Body weight, daily food consumption estimation, toxicity clinical signs evidences, male reproductive system organs and accessory glands weights and testis histometric analysis data were evaluated. Spermatozoa were collected from the cauda epididymis and were subjected to counting and evaluations of vitality and morphology. Complete blood count test, serum biochemistry test of urea, creatinine and alanine aminotransferase (ALT) and total serum testosterone levels were realized. Clinical signs of systemic toxicity and deaths were not seen. In spite of it had had significant statistical differences on daily food consumption estimation, hemoglobinometry, mean corpuscular hemoglobin concentration and Leydig cell volume, it was concluded that GBE in the present study and with the doses used, did not cause systemic toxicity nor promoted alterations on testicular morphometry and spermatic quality of Wistar rats.

Sertoli cells represent the only somatic cell type within the seminiferous tubules with direct contact to germ cells. Sertoli cells significantly contribute to the development of the testicular niche in a male embryo. Their role during postnatal life is in the regulation and nutrition of germ cells and the formation of the blood-testis barrier to protect these cells. In our laboratory, we have been successful in establishing a cell line of X. tropicalis immature Sertoli cells (XtiSCs) derived from juvenile testes of X. tropicalis. The objective of this thesis was to induce the differentiation process of XtiSCs into mature Sertoli cells. In vitro experiments using several factors or primary culture from adult male X. tropicalis did not show any mature markers in differentiated XtiSCs. Another experiment using cell culture derived from pubertal mice was partially successful in the induction of the differentiation process. These results indicate that XtiSCs do have some differentiation potential into mature Sertoli cells. Part of this work was to test the ability of testicular cells isolated from juvenile males of X. tropicalis to form de novo organoids. In vitro experiments were successful when these cells were cultured in a three-layer matrigel.

Le testicule assure la production des spermatozoïdes et la sécrétion de la testostérone. Chaque fonction est assumée par un compartiment cellulaire distinct: l’épithélium séminifère et le tissu interstitiel. Le cholestérol, présent dans les deux compartiments, est un composé indispensable aux membranes cellulaires et un précurseur essentiel de la testostérone. Dans le compartiment interstitiel, environ 40 % du cholestérol utilisé pour la production hormonale est importé du sang à partir des lipoprotéines HDL et/ou LDL. Dans l’épithélium séminifère, la cellule de Sertoli assure le contrôle et le maintien de la spermatogenèse. Elle a la capacité de synthétiser du cholestérol à partir de l’acétate in vitro, néanmoins, il n’y a pas d’évidence qu’elle le fait in vivo. De plus il existe, au niveau des tubules séminifères, une barrière hémato-testiculaire qui empêche le libre passage de plusieurs composés sanguins, y compris le cholestérol. Nous avons testé l’hypothèse qu’il existe des moyens d’importation du cholestérol sanguin, mais aussi l’exportation du cholestérol intra-tissulaire, qui contourneraient cette barrière et qui contribueraient au maintien du taux intratubulaire du cholestérol compatible avec le bon déroulement de la spermatogenèse. Nous avons comparé les taux de variation de l’expression de l’ARNm et de la protéine des transporteurs sélectifs de cholestérol SR-BI, SR-BII, CD36 et ABCA1 aux taux de variation du cholestérol libre et estérifié au cours de la spermatogenèse chez les souris normales durant le développement postnatal. Afin de mieux apprécier le niveau d’implication de chacun de ces récepteurs, nous avons examiné comment la suppression du gène d’une enzyme comme la lypase hormono-sensible (HSL) ou de celui d’un transporteur de cholestérol comme SR-BI, CD36 ou NPC1 était compensée et comment cette suppression affectait le taux de cholestérol libre et estérifié dans chacun des deux compartiments cellulaires du testicule. Nous avons dans un premier temps mis au point une nouvelle technique d’isolation des testicules en fraction enrichie en tissu interstitiel (ITf) et en tubules séminifères (STf) qui a l’avantage de mieux préserver l’intégrité des formes phosphorylées et glycosylées des protéines comparée aux techniques préexistantes. Les résultats de nos analyses ont montré que l’expression de SR-BI et CD36 étaient maximales dans les ITf au moment où les souris ont complété leur maturité sexuelle et où le niveau de synthèse de la testostérone était maximal. Dans les tubules séminifères, l’expression maximale de SR-BI et le taux le plus élevé de cholestérol estérifié étaient mesurés de façon concomitante à 35 jours après la naissance, au moment où la première vague de l’activité spermatogénétique était complétée. L’expression de l’ABCA1 était maximale au moment où le taux de cholestérol était élevé et minimale au moment où le taux de cholestérol était le plus bas, alors que le niveau d’expression de CD36 était maximal chez l’adulte au moment où le taux de spermiation était le plus élevé. L’expression de SR-BII variait peu dans les deux compartiments cellulaires durant le développement. La suppression génétique de la HSL et de NPC1, qui cause une infertilité chez les souris mâles, était accompagnée d’une accumulation de cholestérol libre et estérifié dans les tubules séminifères. Par contre, la suppression génétique de SR-BI et CD36, qui ne causent pas d’infertilité chez les souris mâles était sans impact significatif sur le taux de cholestérol intratubulaire. Nous avons montré que l’invalidation génétique d’un transporteur sélectif ou d’une enzyme du métabolisme du cholestérol était accompagnée d’un ensemble de mécanismes de compensation visant à maintenir le taux de cholestérol libre aux niveaux semblables à ceux mesurés dans les fractions tissulaires de souris normales. Ensemble, nos résultats ont montré que l’expression des transporteurs sélectifs de cholestérol SR-BI, SR-BII, CD36 et ABCA1 variait en fonction de la spermatogenèse et du taux intratesticulaire du cholestérol suggérant leur contribution au maintien de l’homéostasie du cholestérol intratesticulaire. / The testis is made up of loops of convoluted seminiferous tubules surrounded by interstitial tissue composed of loose connective tissue containing Leydig cells that secrete testosterone into the bloodstream. The seminiferous tubules are lined with a stratified epithelium containing germ cells at various stages of development and the supporting Sertoli cells. Cholesterol is present in both compartments and is crucial for the development of germ cells, the fertility of spermatozoa as well as for testosterone production. In the interstitial compartment, approximately 40 % of the cholesterol used for the hormonal production is imported from blood lipoproteins HDL and LDL. In the seminiferous epithelium, Sertoli cells plays key role in the development and maintenance of spermatogenesis. Sertoli cells have the capacity to synthesize cholesterol from acetate in vitro, however, there is no evidence that they do so in vivo. In addition, there is a blood-testis barrier within the seminiferous tubules that prevents the free passage of several blood compounds including cholesterol. We tested the hypothesis that there are ways of blood cholesterol uptake, but also the intratubular cholesterol efflux that by-pass this barrier and contribute to the cholesterol homeostasis within the tubules. We compared expression patterns of the mRNA and proteins for selective cholesterol transporters SR-BI, SR-BII, CD36 and ABCA1 with those of free and esterified cholesterol during the spermatogenesis in normal mice during the postnatal development. To better appreciate the level of involvement of each receptor, we examined the effect of the deletion of the genes for an enzyme (HSL) or for cholesterol transporters (SR-BI, CD36 or NPC1) on the rate of free and esterified cholesterol in both compartments of the testis. At first, we worked out a new technique to separate the testes into interstitial tissue- (ITf) and seminiferous tubule-enriched fractions (STf) that has the advantage of allowing a more faithful detection of the phosphorylated and glycosylated forms of the proteins compared to existing techniques. Our results showed that the expression of SR-BI and CD36 was maximum in the ITf when mice completed their sexual maturity and reached the peak level of testosterone synthesis. In the seminiferous tubule-enriched fractions, the maximum level of SR-BI expression coincided with the highest level of esterified cholesterol during the development at 35 days, as the first wave of the spermatogenetic activity was completed. ABCA1 reached the highest expression level when cholesterol was high and reached the lowest when cholesterol was at its minimum, while the level of CD36 expression was maximal in the adult tubules as the rate of spermiation was the highest. The knockout of the HSL and NPC1, which renders the male mice infertile, was accompanied by the accumulation of free and esterified cholesterol in the seminiferous tubules. On the other hand, the knockout of SR-BI and CD36, linkes to infertility, did not affect the rate of intratubular cholesterol. Here we showed that genetic withdrawal of a cholesterol transporter or of an enzyme involved in cholesterol metabolism was compensated by other transporters or enzymes in order to maintain the level of free cholesterol similar to those measured in the tissue-enriched fractions of wild-type mice. Together, our results showed that the expression of the selective cholesterol transporters SR-BI, SR-BII, CD36 and ABCA1 varied according to the spermatogenesis and intratesticular cholesterol rate, thus suggesting their contribution to the preservation of the intratesticular cholesterol homeostasis.

Le testicule assure la production des spermatozoïdes et la sécrétion de la testostérone. Chaque fonction est assumée par un compartiment cellulaire distinct: l’épithélium séminifère et le tissu interstitiel. Le cholestérol, présent dans les deux compartiments, est un composé indispensable aux membranes cellulaires et un précurseur essentiel de la testostérone. Dans le compartiment interstitiel, environ 40 % du cholestérol utilisé pour la production hormonale est importé du sang à partir des lipoprotéines HDL et/ou LDL. Dans l’épithélium séminifère, la cellule de Sertoli assure le contrôle et le maintien de la spermatogenèse. Elle a la capacité de synthétiser du cholestérol à partir de l’acétate in vitro, néanmoins, il n’y a pas d’évidence qu’elle le fait in vivo. De plus il existe, au niveau des tubules séminifères, une barrière hémato-testiculaire qui empêche le libre passage de plusieurs composés sanguins, y compris le cholestérol. Nous avons testé l’hypothèse qu’il existe des moyens d’importation du cholestérol sanguin, mais aussi l’exportation du cholestérol intra-tissulaire, qui contourneraient cette barrière et qui contribueraient au maintien du taux intratubulaire du cholestérol compatible avec le bon déroulement de la spermatogenèse. Nous avons comparé les taux de variation de l’expression de l’ARNm et de la protéine des transporteurs sélectifs de cholestérol SR-BI, SR-BII, CD36 et ABCA1 aux taux de variation du cholestérol libre et estérifié au cours de la spermatogenèse chez les souris normales durant le développement postnatal. Afin de mieux apprécier le niveau d’implication de chacun de ces récepteurs, nous avons examiné comment la suppression du gène d’une enzyme comme la lypase hormono-sensible (HSL) ou de celui d’un transporteur de cholestérol comme SR-BI, CD36 ou NPC1 était compensée et comment cette suppression affectait le taux de cholestérol libre et estérifié dans chacun des deux compartiments cellulaires du testicule. Nous avons dans un premier temps mis au point une nouvelle technique d’isolation des testicules en fraction enrichie en tissu interstitiel (ITf) et en tubules séminifères (STf) qui a l’avantage de mieux préserver l’intégrité des formes phosphorylées et glycosylées des protéines comparée aux techniques préexistantes. Les résultats de nos analyses ont montré que l’expression de SR-BI et CD36 étaient maximales dans les ITf au moment où les souris ont complété leur maturité sexuelle et où le niveau de synthèse de la testostérone était maximal. Dans les tubules séminifères, l’expression maximale de SR-BI et le taux le plus élevé de cholestérol estérifié étaient mesurés de façon concomitante à 35 jours après la naissance, au moment où la première vague de l’activité spermatogénétique était complétée. L’expression de l’ABCA1 était maximale au moment où le taux de cholestérol était élevé et minimale au moment où le taux de cholestérol était le plus bas, alors que le niveau d’expression de CD36 était maximal chez l’adulte au moment où le taux de spermiation était le plus élevé. L’expression de SR-BII variait peu dans les deux compartiments cellulaires durant le développement. La suppression génétique de la HSL et de NPC1, qui cause une infertilité chez les souris mâles, était accompagnée d’une accumulation de cholestérol libre et estérifié dans les tubules séminifères. Par contre, la suppression génétique de SR-BI et CD36, qui ne causent pas d’infertilité chez les souris mâles était sans impact significatif sur le taux de cholestérol intratubulaire. Nous avons montré que l’invalidation génétique d’un transporteur sélectif ou d’une enzyme du métabolisme du cholestérol était accompagnée d’un ensemble de mécanismes de compensation visant à maintenir le taux de cholestérol libre aux niveaux semblables à ceux mesurés dans les fractions tissulaires de souris normales. Ensemble, nos résultats ont montré que l’expression des transporteurs sélectifs de cholestérol SR-BI, SR-BII, CD36 et ABCA1 variait en fonction de la spermatogenèse et du taux intratesticulaire du cholestérol suggérant leur contribution au maintien de l’homéostasie du cholestérol intratesticulaire. / The testis is made up of loops of convoluted seminiferous tubules surrounded by interstitial tissue composed of loose connective tissue containing Leydig cells that secrete testosterone into the bloodstream. The seminiferous tubules are lined with a stratified epithelium containing germ cells at various stages of development and the supporting Sertoli cells. Cholesterol is present in both compartments and is crucial for the development of germ cells, the fertility of spermatozoa as well as for testosterone production. In the interstitial compartment, approximately 40 % of the cholesterol used for the hormonal production is imported from blood lipoproteins HDL and LDL. In the seminiferous epithelium, Sertoli cells plays key role in the development and maintenance of spermatogenesis. Sertoli cells have the capacity to synthesize cholesterol from acetate in vitro, however, there is no evidence that they do so in vivo. In addition, there is a blood-testis barrier within the seminiferous tubules that prevents the free passage of several blood compounds including cholesterol. We tested the hypothesis that there are ways of blood cholesterol uptake, but also the intratubular cholesterol efflux that by-pass this barrier and contribute to the cholesterol homeostasis within the tubules. We compared expression patterns of the mRNA and proteins for selective cholesterol transporters SR-BI, SR-BII, CD36 and ABCA1 with those of free and esterified cholesterol during the spermatogenesis in normal mice during the postnatal development. To better appreciate the level of involvement of each receptor, we examined the effect of the deletion of the genes for an enzyme (HSL) or for cholesterol transporters (SR-BI, CD36 or NPC1) on the rate of free and esterified cholesterol in both compartments of the testis. At first, we worked out a new technique to separate the testes into interstitial tissue- (ITf) and seminiferous tubule-enriched fractions (STf) that has the advantage of allowing a more faithful detection of the phosphorylated and glycosylated forms of the proteins compared to existing techniques. Our results showed that the expression of SR-BI and CD36 was maximum in the ITf when mice completed their sexual maturity and reached the peak level of testosterone synthesis. In the seminiferous tubule-enriched fractions, the maximum level of SR-BI expression coincided with the highest level of esterified cholesterol during the development at 35 days, as the first wave of the spermatogenetic activity was completed. ABCA1 reached the highest expression level when cholesterol was high and reached the lowest when cholesterol was at its minimum, while the level of CD36 expression was maximal in the adult tubules as the rate of spermiation was the highest. The knockout of the HSL and NPC1, which renders the male mice infertile, was accompanied by the accumulation of free and esterified cholesterol in the seminiferous tubules. On the other hand, the knockout of SR-BI and CD36, linkes to infertility, did not affect the rate of intratubular cholesterol. Here we showed that genetic withdrawal of a cholesterol transporter or of an enzyme involved in cholesterol metabolism was compensated by other transporters or enzymes in order to maintain the level of free cholesterol similar to those measured in the tissue-enriched fractions of wild-type mice. Together, our results showed that the expression of the selective cholesterol transporters SR-BI, SR-BII, CD36 and ABCA1 varied according to the spermatogenesis and intratesticular cholesterol rate, thus suggesting their contribution to the preservation of the intratesticular cholesterol homeostasis.