Estudo histoquímico e imunohistoquímico comparado de testículos retidos e escrotais em cão
Data
2019-02-12
Título da revista
ISSN da revista
Título do Volume
Editora
Resumo
Criptorquidismo define-se como uma falha na descida de um (unilateral) ou ambos (bilateral) os testículos e suas estruturas adjacentes. É uma alteração urogenital presente à nascença (congénito) ou surge com o crescimento do animal (adquirida). Podem resultar na redução da fertilidade assim como no risco aumentado de surgirem neoplasias ou torções testiculares. Com este estudo pretendemos avaliar o padrão de expressão pela técnica de imunohistoquímica das proteínas do citoesqueleto Vimentina e alfa-actina de músculo liso (SMA) e da Fosfatase alcalina (PLAT) em testículos retidos (n = 16) e escrotais (n = 9) em canídeos. As amostras foram recolhidas após a orquiectomia, fixadas em formalina 10% tamponada e embebidas em parafina. Foram cortadas secções com 2 micra e coradas com hematoxilina-eosina (H&E) para avaliação da morfologia testicular. Foi feito um prévio estudo histoquímico, com o propósito de evidenciar as fibras de colagénio e de reticulina assim como confirmar a estratificação do epitélio germinativo dos tubos seminíferos. Nos testículos retidos, as células de Sertoli dispõem-se numa única camada de células, de posição basal e as células germinativas estão frequentemente ausentes. Observou-se que a expressão da alfa-actina (SMA) peri tubular era mais fraca nos testículos retidos quando comparada aos testículos contra-laterais escrotais. O padrão de marcação para a Vimentina mostrou-se diferente de acordo com os estágios do ciclo espermatogênico. Um padrão fraco de coloração peri-nuclear observou-se nos estágios V e VII, enquanto em todos os outros estágios se identificou um padrão moderadamente positivo e perda de expressão foi observada nas células de Leydig. A expressão de PLAT é diminuta nos testículos retidos, e um padrão de expressão peri nuclear nas células peri tubulares mióides é observado. Algumas células germinativas dentro de túbulos seminíferos apresentaram marcação positiva. No nosso estudo, e tendo em conta a localização dos testículos, observamos que o índice de espermatogonias é menor nos testículos abdominais do que nos testículos escrotais. A localização do testículo fora da bolsa testicular afecta a morfologia do órgão, quer na lâmina própria, quer na espermatogénese, havendo também uma diminuição do tecido intersticial. Como resultado, há perda da espermatogénese que culmina na redução da fertilidade.
Cryptorchidism is as a failure of descent of one (unilateral) or both (bilateral) testes and its associated structures. Is a urogenital abnormality that may be present at birth (congenital form) or developed later (acquired form), usually cause impaired spermatogenesis resulting in reduce fertility and related to increased rates of testicular neoplasia and torsion. With this study we aim to analysis the immunohistochemistry expression pattern for the cytoskeletal proteins vimentin (Vim) and alfa-smooth muscle actin (SMA) and alkaline phosphatase (PLAT) in dog testes retained (n=10) and scrotal (n=9). Samples were collected after orchiectomy, fixed in 10% buffered formalin and embedded in paraffin wax. Section with 2 micra were stained with heamatoxylin-eosin to morphology analysis. A previous histochemical study was done with the purpose of evidencing the collagen and reticulin fibers, and to confirm the stratification of the germinal cells of the seminiferous tubes. In retain testes Sertoli cells are arranged in a single basal layer and germ cells were most frequently absent. A weaker peritubular alfa-SMA labbeling was observed in retained testes when compared to the contralateral normal testes. Vimentin positivity pattern showed to be different according to stages of spermatogenic cycle. Peri-nuclear staining with a weak pattern, was observed at stages V and VII, while in all other stages was noticed an moderate pattern. A loss of the expression to this marker was perceived on Leydig cells. PLAT expression is decreased in retain testes, and a perinuclear patter of expression by peritubular myoid cells was observed. Some isolated germ cells within seminiferous tubules were observed positive. In our study, we observed that the spermatogonia proliferation index is lower in the abdominal testes than in the scrotal ones. The cryptorchidism affected the morphology and function (spermatogenesis) of the testes. As result of the interstitial tissue decrease was observed a loss of spermatogonia’s and consequent reduction of fertility.
Cryptorchidism is as a failure of descent of one (unilateral) or both (bilateral) testes and its associated structures. Is a urogenital abnormality that may be present at birth (congenital form) or developed later (acquired form), usually cause impaired spermatogenesis resulting in reduce fertility and related to increased rates of testicular neoplasia and torsion. With this study we aim to analysis the immunohistochemistry expression pattern for the cytoskeletal proteins vimentin (Vim) and alfa-smooth muscle actin (SMA) and alkaline phosphatase (PLAT) in dog testes retained (n=10) and scrotal (n=9). Samples were collected after orchiectomy, fixed in 10% buffered formalin and embedded in paraffin wax. Section with 2 micra were stained with heamatoxylin-eosin to morphology analysis. A previous histochemical study was done with the purpose of evidencing the collagen and reticulin fibers, and to confirm the stratification of the germinal cells of the seminiferous tubes. In retain testes Sertoli cells are arranged in a single basal layer and germ cells were most frequently absent. A weaker peritubular alfa-SMA labbeling was observed in retained testes when compared to the contralateral normal testes. Vimentin positivity pattern showed to be different according to stages of spermatogenic cycle. Peri-nuclear staining with a weak pattern, was observed at stages V and VII, while in all other stages was noticed an moderate pattern. A loss of the expression to this marker was perceived on Leydig cells. PLAT expression is decreased in retain testes, and a perinuclear patter of expression by peritubular myoid cells was observed. Some isolated germ cells within seminiferous tubules were observed positive. In our study, we observed that the spermatogonia proliferation index is lower in the abdominal testes than in the scrotal ones. The cryptorchidism affected the morphology and function (spermatogenesis) of the testes. As result of the interstitial tissue decrease was observed a loss of spermatogonia’s and consequent reduction of fertility.
Descrição
Dissertação de Mestrado Integrado em Medicina Veterinária