RESUMO
The aim was to study the ultrastructure of testicular parenchyma and define the morphological ultrastructure of spermatozoa of agoutis kept in captivity. Segments of testes from eight agouti males at prepubescence, prepuberty, pubescence and sexual maturity were fixed in glutaraldehyde. Laboratory procedures were performed for transmission electron microscopy. Spermatogonial cells of Type A - pale, Type A - dark, intermediate and Type B were found. Spermatocytes in the pachytene phase were abundant among primary spermatocytes. From the prepubertal phase, Sertoli cells exhibited invaginations in the nuclear membrane and lipid inclusions in the cytoplasm due to their phagocytic function. Leydig cells displayed higher metabolic activity during puberty as evidenced by the presence of lipid droplets. Spermatozoa were fully formed morphologically at prepuberty. The centriolar complex had partially degenerated and featured a centriolar space as in rodents. Sperm heads were tapered, without prominence of the acrosome or evidence of the perforatorium, differing from cavies, rats and mice. This is the first study to describe the ultrastructure of agouti spermatozoa. This research may assist as a basis for future work related to fertility and other biotechnologies applied to reproductive biology in agoutis.
Assuntos
Maturidade Sexual/fisiologia , Cabeça do Espermatozoide/ultraestrutura , Espermatogênese/fisiologia , Espermatozoides/ultraestrutura , Testículo/ultraestrutura , Animais , Dasyproctidae , Células Intersticiais do Testículo/ultraestrutura , Masculino , Células de Sertoli/ultraestrutura , Espermátides/ultraestrutura , Espermatócitos/ultraestrutura , Espermatogônias/ultraestruturaRESUMO
Spermatogenesis is disrupted in Graomys griseoflavus×Graomys centralis male hybrids. This study was aimed to determine whether morphological alterations in Leydig cells from hybrids accompany the arrest of spermatogenesis and cell death of germ cells and whether apoptotic pathways are also involved in the response of these interstitial cells. We used three groups of 1-, 2- and 3-month-old male animals: (1) G. centralis, (2) G. griseoflavus and (3) hybrids obtained by crossing G. griseoflavus females with G. centralis males. Testicular ultrastructure was analyzed by transmission electron microscopy. TUNEL was studied using an in situ cell death detection kit and the expression of apoptotic molecules by immunohistochemistry. The data confirmed arrest of spermatogenesis and intense apoptotic processes of germ cells in hybrids. These animals also showed ultrastructural alterations in the Leydig cells. Fas, FasL and calbindin D28k overexpression without an increase in DNA fragmentation was detected in the Leydig cells from hybrids. In conclusion, the sterility of Graomys hybrids occurs with ultrastructural changes in germ and Leydig cells. The enhancement of Fas and FasL is not associated with cell death in the Leydig cells. Probably the apoptosis in these interstitial cells is inhibited by the high expression of the antiapoptotic molecule calbindin D28k.
Assuntos
Apoptose , Células Intersticiais do Testículo/fisiologia , Roedores/anatomia & histologia , Animais , Calbindinas/metabolismo , Proteína Ligante Fas/metabolismo , Feminino , Hibridização Genética , Células Intersticiais do Testículo/ultraestrutura , Masculino , Túbulos Seminíferos/citologia , Túbulos Seminíferos/metabolismo , Espermatogênese , Receptor fas/metabolismoRESUMO
This was a pioneer study of the spermatogenic process from the onset of puberty in Spix's yellow-toothed cavies (SYC, Galea spixii) bred in captivity. The study aimed to characterize fine structure of spermatogenesis. Twelve testes from pubertal and post-pubertal SYC males were studied using transmission electron microscopy. Spermatogenesis can be divided into three phases: proliferation, meiosis, and spermiogenesis. In proliferation phase, three types of spermatogonia were identified and characterized as A(dark), A(pale), and B. In the second phase, spermatocytes (2n) undergo meiotic divisions that generate spermatids (n); the process begins in spermatocytes in the preleptotene stage when they increase their nuclear size, differentiating into spermatocytes in the leptotene stage when cell division is initiated. In addition, we found chromatin condensation, and formation of a structure composed of proteins that formed a central shaft and two lateral bars associated with pairing of homologous chromosomes. During spermiogenesis, the following main events occurred: condensation of nuclear chromatin, formation of acrosome with perfuratorium, elimination of residual cytoplasm, and development of the flagellum. The sperm head is different from that of other rodents. The endoplasmic reticulum and the Golgi complex are the two main organelles demonstrated during this process. These organelles collaborate through synthesis of proteins and hormones for the development of germ cells during spermatogenesis in SYC.
Assuntos
Espermátides/ultraestrutura , Espermatócitos/ultraestrutura , Espermatogênese/fisiologia , Espermatogônias/ultraestrutura , Espermatozoides/ultraestrutura , Animais , Cobaias , Células Intersticiais do Testículo/ultraestrutura , Masculino , Células de Sertoli/ultraestrutura , Testículo/ultraestruturaRESUMO
The aim of this study was to examine the effect of maternal exposure to Panax ginseng extract (GE) on the prenatal dexamethasone (DEXA)-induced increase in testosterone production by isolated Leydig cells in adult rats. Pregnant rats were treated with (i) GE (200 mg/kg) or vehicle on days 10-21; (ii) DEXA (100 µg/kg) or vehicle on days 14-21; or (iii) a combination of GE plus DEXA at the same doses and with the same regimen. Testosterone production was induced either by the activator of protein kinase A (dbcAMP) or substrates of steroidogenesis [22(R)-hydroxycholesterol (22(R)-OH-C)] and pregnenolone. The capacity of rat Leydig cells exposed to DEXA to synthesize testosterone induced by dbcAMP, 22(R)-OH-C or pregnenolone was increased in comparison with the control group. Combined exposure to DEXA + GE prevented the effect of DEXA on the responsiveness of Leydig cells to all inductors of testosterone synthesis, whereas GE alone did not modify the response to inductors. No modifications in testosterone production were observed under basal conditions. StAR immunoexpression in Leydig cells was not modified by prenatal exposure to DEXA, GE or DEXA + GE. P450scc and glucocorticoid receptor immunoexpression was higher in offspring exposed to DEXA in comparison with the control group. This increased expression was prevented by combined treatment with DEXA + GE. The present findings demonstrate that GE is capable of reversing the effect of DEXA on testosterone synthesis by rat Leydig cells.
Assuntos
Dexametasona/farmacologia , Células Intersticiais do Testículo/metabolismo , Panax/química , Extratos Vegetais/farmacologia , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Testosterona/biossíntese , Fatores Etários , Animais , Peso Corporal/efeitos dos fármacos , Enzima de Clivagem da Cadeia Lateral do Colesterol/metabolismo , Interações Medicamentosas , Feminino , Glucocorticoides/farmacologia , Células Intersticiais do Testículo/ultraestrutura , Masculino , Microscopia Eletrônica de Transmissão , Tamanho do Órgão/efeitos dos fármacos , Fosfoproteínas/metabolismo , Gravidez , Ratos , Ratos Wistar , Testículo/citologia , Testículo/efeitos dos fármacos , Testículo/metabolismo , Testosterona/sangueRESUMO
Environmental factors can influence the reproductive rates in bats, and since morphometric information of bats testis is scarce, we aimed to compare the organization and quantification of the intertubular components in the testes of the bat Molossus molossus, collected in different seasons. Testicular histological sections were evaluated using light and electron microscopy. The intertubular compartment occupied an average 10% of the testes, being predominately constituted of Leydig cells (LC). The percentages of the testes occupied by the intertubular compartment and by LC were significantly higher in summer, while the other intertubular components did not vary significantly among the seasons. As suspected under light microscopy, the ultrastructural analysis confirmed the existence of multinucleated LC during winter. The increase in the nuclear percentage of LC in winter seems to have caused the decrease of the cytoplasmatic measurements in that season, as well as in the volume of LC. The highest cytoplasmatic values and volume of LC registered in the spring, summer, and fall can be related to greater activity of this cell in these seasons. The higher investment in intertubular tissue and in LC observed in summer, compared to winter; suggest an increase in the steroidogenic capacity of this bat during summer. The analyses correlating testicular morphometry and abiotic environmental factors in this study confirm the influence of climatic factors on the reproduction of M. molossus.
Assuntos
Quirópteros/anatomia & histologia , Túbulos Seminíferos/ultraestrutura , Animais , Quirópteros/fisiologia , Células Intersticiais do Testículo/ultraestrutura , Masculino , Microscopia Eletrônica , Tamanho do Órgão , Reprodução , Estações do Ano , Túbulos Seminíferos/crescimento & desenvolvimento , Testículo/crescimento & desenvolvimento , Testículo/ultraestruturaRESUMO
Testicles of 30 mongrel cats were analyzed histologically and morphometrically, divided into three groups: G1 (1-2 years old), G2 (over 2 and up to 4 years old) and G3 (over 4 and up to 6 years old). After orchiectomy and histopathology, the morphometric parameters studied were: thickness of the tunica albuginea (72 µm) and seminiferous epithelium (77.19 µm), perimeter (53.81; 90.57 µm), (54.80; 101.07 µm); area (174.23; 494.55 µm(2)), (176.68; 629.70 µm(2)); maximum diameter (14.94; 28.02 µm), (14.76; 31.66 µm); minimum diameter (13.25; 21.92 µm), (13.30; 24.52 µm); and shape factor (index for regularity of the format) (1.36; 1.36), (1.39; 1.35) of the nucleus and cytoplasm of spermatogonia and Leydig cells, respectively. The results can be used for comparative studies and contribute knowledge concerning the height of the seminiferous epithelium, thickness of the tunica albuginea and size of spermatogonia and Leydig cells.
Assuntos
Gatos/anatomia & histologia , Testículo/anatomia & histologia , Fatores Etários , Animais , Técnicas Histológicas/veterinária , Células Intersticiais do Testículo/citologia , Células Intersticiais do Testículo/ultraestrutura , Masculino , Orquiectomia/veterinária , Espermatogônias/citologia , Espermatogônias/ultraestrutura , Testículo/citologiaRESUMO
Spermatogenesis, the remarkable process of morphological and biochemical transformation and cell division of diploid stem cells into haploid elongated spermatozoa, is one of the most complex cell differentiations found in animals. This differentiation process has attracted extensive studies, not only because the process involves many radical changes in the cell shape and biochemistry, but also because the phases and steps of differentiation have provided a better basis for analyzing the seminiferous epithelium cycle. Thus, this study aimed to characterize ultrastructurally the spermatogenesis process in the bat Platyrrhinus lineatus in order to provide a basis for determining the stages of spermatogenesis and to facilitate comparisons of the process between bat species and other vertebrates. Based on ultrastructural characteristics three main types of spermatogonia could be accurately identified: A(d), A(p) and B; the differentiation of spermatids was clearly divided into 12 steps (steps 1-3: Golgi phase, steps 4-5: cap phase, steps 6-9: acrosomal phase and steps 10-12: maturation phase). The ultrastructure of spermatozoa, Leydig cells and Sertoli cells was characterized; and some processes including nucleolar disorganization and the formation of synaptonemal complexes, acrosome and chromatoid body were discussed. Based on our results we may conclude that the spermatogenic process of P. lineatus follows the pattern of mammals with some specificity, as the process of formation of the acrosome and the presence of the perfuratorium. By other side, the simpler ultrastructure of its spermatozoon shows a pattern more closely related to the sperm cells of humans and other primates.
Assuntos
Quirópteros , Espermátides/ultraestrutura , Espermatogênese , Espermatogônias/ultraestrutura , Acrossomo/ultraestrutura , Animais , Células Intersticiais do Testículo/ultraestrutura , Masculino , Células de Sertoli/ultraestrutura , Complexo Sinaptonêmico/ultraestruturaRESUMO
Although seminiferous tubule maturation in horses begins in the central area of the testis, this process is thought to occur randomly throughout the testis in most mammals. Studies in our laboratory revealed that the establishment of spermatogenesis may not be a synchronous event in the testicular parenchyma of pigs. The objectives of the present study were to evaluate the pattern of seminiferous cord/tubule maturation and the morphological and functional characteristics of testicular somatic cells during postnatal development in three regions of the pig testis: a) near the tunica albuginea (TA); b) in the transitional area between the seminiferous tubules and mediastinum (TR); and c) in the intermediate area (ID) between the TA and TR. Based on the diameter of seminiferous cords/tubules, nucleus size of Sertoli cells and fluid secretion, mainly at 90 and 120 d of age, seminiferous tubule maturation was more advanced in the ID and TR. The mitotic activity of Sertoli cells was higher (P<0.05) in the TR than the ID and TA at 7 and 120 d. Except for the mitotic index of the Leydig cells, which was lower (P<0.05) in the ID at 7, 30, and 180 d than in the TA and TR, other Leydig cell ebd points, e.g., individual cell size, nuclear volume, and cytoplasmic volume, were consistently higher (P<0.05) in the ID, suggesting that steroidogenesis was more active in this region during the period investigated. Overall, we inferred that Leydig cells in the ID may play a pivotal role in postnatal testis development in pigs and this type of cell is likely related to asynchronous testicular parenchyma development, with the transitional area providing the primary zone for growth of seminiferous tubules.
Assuntos
Divisão Celular , Túbulos Seminíferos/crescimento & desenvolvimento , Suínos/crescimento & desenvolvimento , Testículo/citologia , Testículo/crescimento & desenvolvimento , Animais , Núcleo Celular/ultraestrutura , Citoplasma/ultraestrutura , Células Intersticiais do Testículo/fisiologia , Células Intersticiais do Testículo/ultraestrutura , Masculino , Mitose , Células de Sertoli/fisiologia , Células de Sertoli/ultraestrutura , Maturidade Sexual , EspermatogêneseRESUMO
BACKGROUND: The present study was designed to examine the effect of chronic treatment with rosiglitazone - thiazolidinedione used in the treatment of type 2 diabetes mellitus for its insulin sensitizing effects - on the Leydig cell steroidogenic capacity and expression of the steroidogenic acute regulatory protein (StAR) and cholesterol side-chain cleavage enzyme (P450scc) in normal adult rats. METHODS: Twelve adult male Wistar rats were treated with rosiglitazone (5 mg/kg) administered by gavage for 15 days. Twelve control animals were treated with the vehicle. The ability of rosiglitazone to directly affect the production of testosterone by Leydig cells ex vivo was evaluated using isolated Leydig cells from rosiglitazone-treated rats. Testosterone production was induced either by activators of the cAMP/PKA pathway (hCG and dbcAMP) or substrates of steroidogenesis [22(R)-hydroxy-cholesterol (22(R)-OH-C), which is a substrate for the P450scc enzyme, and pregnenolone, which is the product of the P450scc-catalyzed step]. Testosterone in plasma and in incubation medium was measured by radioimmunoassay. The StAR and P450scc expression was detected by immunocytochemistry. RESULTS: The levels of total circulating testosterone were not altered by rosiglitazone treatment. A decrease in basal or induced testosterone production occurred in the Leydig cells of rosiglitazone-treated rats. The ultrastructural and immunocytochemical analysis of Leydig cells from rosiglitazone-treated rats revealed cells with characteristics of increased activity as well as increased StAR and P450scc expression, which are key proteins in androgen biosynthesis. However, a number of rosiglitazone-treated cells exhibited significant mitochondrial damage. CONCLUSION: The results revealed that the Leydig cells from rosiglitazone-treated rats showed significant reduction in testosterone production under basal, hCG/dbcAMP- or 22 (R)-OH-C/pregnenolone-induced conditions, although increased labeling of StAR and P450scc was detected in these cells by immunocytochemistry. The ultrastructural study suggested that the lower levels of testosterone produced by these cells could be due to mitochondrial damage induced by rosiglitazone.
Assuntos
Células Intersticiais do Testículo/efeitos dos fármacos , Esteroides/biossíntese , Tiazolidinedionas/farmacologia , Animais , Peso Corporal/efeitos dos fármacos , Células Cultivadas , Enzima de Clivagem da Cadeia Lateral do Colesterol/metabolismo , Avaliação Pré-Clínica de Medicamentos , Hipoglicemiantes/efeitos adversos , Hipoglicemiantes/farmacologia , Células Intersticiais do Testículo/metabolismo , Células Intersticiais do Testículo/ultraestrutura , Masculino , Tamanho do Órgão/efeitos dos fármacos , Fosfoproteínas/metabolismo , Ratos , Ratos Wistar , Rosiglitazona , Glândulas Seminais/citologia , Glândulas Seminais/efeitos dos fármacos , Testículo/citologia , Testículo/efeitos dos fármacos , Testosterona/sangue , Tiazolidinedionas/efeitos adversos , Fatores de TempoRESUMO
The severe environments where Phymaturus lizards inhabit in the Andes highlands and in Patagonia, Argentina, impose restrictions on their reproduction, offering a framework for the development of life history strategies to overcome hard weather conditions. Among them, prolonged female cycles, asynchrony between sexes in receptivity, and sperm storage in males, were described. Asynchrony in the reproductive timing between males and females is a consequence of different energy requirements for gametogenesis, and often imply the existence of cellular mechanisms to enhance fertilization, such as the asynchronic steroid synthesis between testicular compartments, allowing gametogenesis independently of mating. In the present study ultrastructural and hormone assays were combined for the first time in liolaemids. Specifically, morphological features of steroid activity in Leydig and Sertoli cells, and serum testosterone concentrations have been studied in the lizard Phymaturus antofagastensis. Leydig and Sertoli cells presented morphological features characteristic of steroid synthesis during the spermatogenesis, and evident asynchronic steroid production between testicular compartments. Active Sertoli cells and inactive Leydig cells were observed in spring and autumn, while in mid-summer their steroid activity was synchronic in coincidence with maximal abundance of spermatozoa in epididymis. Serum testosterone concentration was at its maximum in mid-summer (126-230 ng ml(-1)), and minimum in late spring (4-24 ng ml(-1)) and early autumn (2-17 ng ml(-1)). In view of these results, P. antofagastensis males show an original approach to adjust their reproductive activity to physiological and environmental constraints at high latitudes and altitudes in the Andean highlands of Argentina.
Assuntos
Células Intersticiais do Testículo/ultraestrutura , Lagartos/metabolismo , Lagartos/fisiologia , Células de Sertoli/ultraestrutura , Espermatogênese/fisiologia , Testosterona/sangue , Animais , Masculino , Microscopia Eletrônica de TransmissãoRESUMO
In spite of widespread application of flutamide in the endocrine therapies of young and adult patients, the side effects of this antiandrogen on spermatogenesis and germ-cell morphology remain unclear. This study evaluates the short-term androgen blockage effect induced by the administration of flutamide to the testes of pubertal (30-day old) and adult (65- and 135-day old) guinea pigs, with an emphasis on ultrastructural alterations of main cell types. The testes removed after 10 days of treatment with either a non-steroidal antiandrogen, flutamide (10 mg/kg of body weight) or a pharmacological vehicle alone were processed for histological, quantitative and ultrastructural analysis. In pubertal animals, flutamide androgenic blockage induces spermatogonial differentiation and accelerates testes maturation, causing degeneration and detachment of primary spermatocytes and round spermatids, which are subsequently found in great quantities in the epididymis caput. In post-pubertal and adult guinea pigs, in addition to causing germ-cell degeneration, especially in primary spermatocytes, and leading to the premature detachment of spherical spermatids, the antiandrogen treatment increased the relative volume of Leydig cells. In addition, ultrastructural evaluation indicated that irrespective of age antiandrogen treatment causes an increase in frequency of organelles involved with steroid hormone synthesis in the Leydig cells and a dramatic accumulation of myelin figures in their cytoplasm and, to a larger degree, in Sertoli cells. In conclusion, the transient exposition of the guinea pigs to flutamide, at all postnatal ages causes some degenerative lesions including severe premature detachment of spermatids and accumulation of myelin bodies in Leydig and Sertoli cells, compromising, at least temporarily, the spermatogenesis.
Assuntos
Antagonistas de Androgênios/administração & dosagem , Flutamida/administração & dosagem , Cobaias/anatomia & histologia , Espermátides/efeitos dos fármacos , Testículo/efeitos dos fármacos , Animais , Células Intersticiais do Testículo/efeitos dos fármacos , Células Intersticiais do Testículo/ultraestrutura , Masculino , Microscopia Eletrônica de Transmissão , Bainha de Mielina , Organelas/ultraestrutura , Túbulos Seminíferos/anatomia & histologia , Túbulos Seminíferos/efeitos dos fármacos , Células de Sertoli/efeitos dos fármacos , Células de Sertoli/ultraestrutura , Maturidade Sexual , Espermátides/fisiologia , Espermátides/ultraestrutura , Espermatogênese/efeitos dos fármacos , Testículo/crescimento & desenvolvimento , Testículo/ultraestruturaRESUMO
The phosphodiesterase type 5 (PDE5) inhibitor, Sildenafil, is a novel, oral treatment approach for pulmonary hypertension. As Leydig cells present PDE5, this study was conducted to investigate the effects of the chronic treatment with Sildenafil (25 mg/kg) on male Swiss Webster mice steroidogenesis. After a 4-week long experimental design, Leydig cells were analysed by morphological and immunocytochemical procedures. Serum testosterone was assayed by radioimmunoassay. Leydig cells presented noteworthy ultrastructural alterations, such as a vesicular smooth endoplasmic reticulum, large vacuoles scattered through the cytoplasm, enlarged mitochondria with discontinue cristaes and whorle membranes with vesicles at the periphery, which are typical characteristics of an activated steroid-secreting cell. Important immunocytochemical labelling for steroidogenic acute regulatory protein, cytochrome P450 side-chain cleavage enzyme and testosterone were detected in isolated Leydig cells. In addition, Sildenafil-treated mice showed significant increased levels of total testosterone. The results obtained in the present study are consistent with the hypothesis that the accumulation of cyclic guanosine monophosphate by PDE5 inhibition could be involved in the androgen biosynthesis stimulation. Important clinical implications of hormonal disorders should be taken into account for patients with pulmonary hypertension.
Assuntos
Células Intersticiais do Testículo/metabolismo , Inibidores da Fosfodiesterase 5 , Piperazinas/farmacologia , Sulfonas/farmacologia , Testosterona/biossíntese , Vasodilatadores/farmacologia , Animais , Células Cultivadas , Enzima de Clivagem da Cadeia Lateral do Colesterol/análise , Imuno-Histoquímica , Células Intersticiais do Testículo/efeitos dos fármacos , Células Intersticiais do Testículo/ultraestrutura , Masculino , Camundongos , Camundongos Endogâmicos , Microscopia Eletrônica de Transmissão , Fosfoproteínas/análise , Purinas/farmacologia , Citrato de Sildenafila , Estimulação Química , Testosterona/análise , Testosterona/sangueRESUMO
Diethylcarbamazine (DEC) has been proven to be highly effective against lymphatic filariasis, although its effect on vertebrate cells remains uncertain. Mice Leydig cells after treatment with 200mg/kg of DEC for 12 days showed numerous lipid droplets, degenerated mitochondria, residual bodies and several giant whorl-like smooth endoplasmic reticulum, some of them encircling large lipids droplets. Treatment with lower dosages showed similar alterations on Leydig cells and the morphological effects decreased directly proportional to the drug concentration. Serum testosterone levels were significantly lower only in 200 mg/kg DEC-treated group when compared to the controls. However, no significant changes were observed in the pregnancy rates and offspring number of DEC-treated male-mated female mice in any doses studied. The results obtained in the present study are consistent with the hypothesis that DEC has some effects on mice Leydig cells, although they were not sufficient enough to interfere with the rodent fertility.
Assuntos
Dietilcarbamazina , Filaricidas , Células Intersticiais do Testículo , Testículo/citologia , Testículo/efeitos dos fármacos , Testosterona/metabolismo , Animais , Dietilcarbamazina/administração & dosagem , Dietilcarbamazina/farmacologia , Relação Dose-Resposta a Droga , Feminino , Fertilidade , Filaricidas/administração & dosagem , Filaricidas/farmacologia , Células Intersticiais do Testículo/efeitos dos fármacos , Células Intersticiais do Testículo/metabolismo , Células Intersticiais do Testículo/ultraestrutura , Lipídeos/análise , Masculino , Camundongos , Microscopia Eletrônica de Transmissão , Gravidez , Testículo/ultraestruturaRESUMO
O ducto epididimário (DE) de codorna doméstica mostrou, ao longo do ano, variabilidade pequena, porém muito expressiva no outono, o qual corresponde à fase quiescente do ciclo testicular anual. A morfologia do DE na primavera foi, em termos, similar à verificada no verão e inverno. Nestas fases notaram-se aumento significante do calibre tubular do DE; estocagem intraluminal de espermatozóides e ocorrência de mitocôndrias, lamelas do RE, vesículas variáveis quanto à forma, dimensões e conteúdos e presença de alguns lisossomos localizados, principalmente, no citoplasma apical das células principais (P), no epitélio epididimário. Estas características ultra-estruturais das células P parecem ser indicativas da ocorrência de processos ativos de endocitose e de secreção micromerócrina. A quiescência outonal foi caracterizada pelo aspecto anfractuoso do DE; ausência de espermatozóides e pouco material intraluminal, observados à microscopia de luz. Características ultra-estruturais degenerativas foram verificadas ao nível do citoplasma supranuclear das células P epididimárias no outono.
Small but expressive variability was noted on the epididymidis duct (ED) of domestic quail along the year, with more evidence in autumn of the quiescent phase of the annual testis cycle in this species. Spring features of ED had a general similar pattern in summer and winter. They were characterized by enlargement of epididymis tubule, storage of spermatozoa into the luminal compartment and presence of mitochondria, ER lamellae, several variable vesicles, and lysosomes localized mainly on the apical cytoplasm of principal cells (P) of the epididymal epithelium. These P cells features indicated a process of endocytosis and perhaps protein secretion. Autumn quiescence was marked by a convolute pattern of the epididymis tubule, lacking of spermatozoa and small amount of exfoliate heterogeneous material inside the luminal compartment at light microscopy. Ultrastructural degenerative features mainly apical cytoplasmic debris were seen in the supranuclear cytoplasm of lining P cells.
Assuntos
Animais , Células Intersticiais do Testículo/ultraestrutura , Microscopia de Polarização/métodos , Codorniz , Rede do Testículo/anatomia & histologiaRESUMO
O ducto epididimário (DE) de codorna doméstica mostrou, ao longo do ano, variabilidade pequena, porém muito expressiva no outono, o qual corresponde à fase quiescente do ciclo testicular anual. A morfologia do DE na primavera foi, em termos, similar à verificada no verão e inverno. Nestas fases notaram-se aumento significante do calibre tubular do DE; estocagem intraluminal de espermatozóides e ocorrência de mitocôndrias, lamelas do RE, vesículas variáveis quanto à forma, dimensões e conteúdos e presença de alguns lisossomos localizados, principalmente, no citoplasma apical das células principais (P), no epitélio epididimário. Estas características ultra-estruturais das células P parecem ser indicativas da ocorrência de processos ativos de endocitose e de secreção micromerócrina. A quiescência outonal foi caracterizada pelo aspecto anfractuoso do DE; ausência de espermatozóides e pouco material intraluminal, observados à microscopia de luz. Características ultra-estruturais degenerativas foram verificadas ao nível do citoplasma supranuclear das células P epididimárias no outono.(AU)
Small but expressive variability was noted on the epididymidis duct (ED) of domestic quail along the year, with more evidence in autumn of the quiescent phase of the annual testis cycle in this species. Spring features of ED had a general similar pattern in summer and winter. They were characterized by enlargement of epididymis tubule, storage of spermatozoa into the luminal compartment and presence of mitochondria, ER lamellae, several variable vesicles, and lysosomes localized mainly on the apical cytoplasm of principal cells (P) of the epididymal epithelium. These P cells features indicated a process of endocytosis and perhaps protein secretion. Autumn quiescence was marked by a convolute pattern of the epididymis tubule, lacking of spermatozoa and small amount of exfoliate heterogeneous material inside the luminal compartment at light microscopy. Ultrastructural degenerative features mainly apical cytoplasmic debris were seen in the supranuclear cytoplasm of lining P cells.(AU)
Assuntos
Animais , Rede do Testículo/anatomia & histologia , Células Intersticiais do Testículo/ultraestrutura , Microscopia de Polarização/métodos , CodornizRESUMO
Ectothermic vertebrates have a well-developed system of melanin-containing cells, which localize in several organs and tissues and compose an extracutaneous pigmentary system. This research aimed at characterizing histological and ultrastructural patterns of pigmented cells in the testes of the anura Eupemphix nattereri (Steindachner, 1963), including the stereological and quantitative evaluation of this cell type in the gonads. Ten adult males were collected in Nova Itapirema, São Paulo, Brazil, and submitted to morphological studies with light and transmission electron microscopy. The testis presents a great number of large cells with many brown granules and long cytoplasmic processes. The pigmented cells found in the testis are structurally similar to melanocytes, characterized by large amounts of melanosomes. The cells may be in intimate contact with the same cell type, with myoid cells surrounded by a large amount of collagen fibers, Leydig cells, and next to fibroblasts. The distribution and amount of extracutaneous melanocytes is variable when other organs and membranes are analyzed, allowing the establishment of species-specific patterns for the extracutaneous pigmentary system.
Assuntos
Anuros/anatomia & histologia , Melanócitos/ultraestrutura , Testículo/anatomia & histologia , Animais , Brasil , Tamanho Celular , Colágeno/ultraestrutura , Citoesqueleto/ultraestrutura , Fibroblastos/ultraestrutura , Células Intersticiais do Testículo/ultraestrutura , Masculino , Melanossomas/ultraestrutura , Microscopia Eletrônica de Transmissão , Tamanho do Órgão , Túbulos Seminíferos/anatomia & histologia , Testículo/citologiaRESUMO
In classical textbooks of parasitology, the mature proglottids of taeniids are depicted as structures in which the individual testis are connected to the vas deferens through the vas efferens system, usually depicted as a network of channels. From our morphological analyses of proglottids in the cestode Taenia crassiceps, we have been unable to identify this channel network. It is unclear how the spermatids are transported from the testes to the vas deferens, as is unresolved the location of the cells responsible for the production of testosterone (Leydig cells) or the possible equivalent of Sertoli cells, necessary for the differentiation process of these cells. In this experimental work, we have examined the ultrastructure of tissues in the vicinity of the vas deferens in mature proglottids obtained from the intestines of hamsters infected with cysticerci from the peritoneum of infected mice. Worm tissues were fixed, processed, and sectioned for transmission electron microscopy. Significant areas of the testis epithelia emitted cytoplasmic projections surrounded by extracellular matrix, where they appear as septated pockets enclosing free axonemes and spermatids. Vas efferens walls are made up of nucleated cells with cytoplasm annealing to each other through cell membrane junctions. Lodged between the junctions are membrane-bound pouches with dense granules found as aggregates or aligned in a semicircular array. The efferens wall exhibits numerous spermatids emerging into the lumen, an observation that suggests the epithelial wall may have the maturing functions of Sertoli cells of vertebrates. Large cells adjacent to the vas efferens contained prominent rough endoplasmic reticulum and large mitochondria, characteristics described for Leydig cells of vertebrates. Our observations suggest that taeniid spermatids are either transported from the testes to the vas system by epithelial pockets or that the epithelial pockets may be cross-sections of a highly coiled vas efferens system.
Assuntos
Transporte Biológico , Espermátides/fisiologia , Espermátides/ultraestrutura , Taenia/ultraestrutura , Testículo/ultraestrutura , Animais , Feminino , Células Intersticiais do Testículo/citologia , Células Intersticiais do Testículo/ultraestrutura , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Eletrônica de Transmissão , Taenia/fisiologia , Teníase/parasitologia , Testículo/citologia , Testículo/fisiologia , Ducto Deferente/fisiologia , Ducto Deferente/ultraestruturaRESUMO
The freshwater fish Serrasalmus spilopleura (piranha) has a continuous type of reproduction; gametes are constantly produced and released during the reproductive cycle. The testes do not undergo seasonal morphological changes but exhibit two constant regions throughout the year: the medullar region (involved with spermatogenesis) and the cortical region (involved with spermiation and sperm storage). We have evaluated the ultrastructure of the Leydig cells and the activity of 3beta-HSD (an essential enzyme related to steroid hormone biosynthesis) and acid phosphatase (AcPase; lysosomal marker enzyme) in these two regions. The activity of 3beta-HSD is stronger in the medullar region, and the Leydig cells in this region have a variety of cytological features that reflect differences in hormone synthesis and/or that could be linked to steroidogenic cells under various degrees of hormonal activity. In the cortical region, 3beta-HSD activity is weak and the Leydig cells exhibit signs of degeneration, as confirmed by their ultrastructure and intense AcPase activity. These degenerative signs are indicative of cytoplasmic remodelling to degrade steroidogenic enzymes, such as 3beta-HSD, that could lead to senescence or even to autophagic cell degeneration. S. spilopleura thus constitutes an interesting model for increasing our understanding of steroidogenesis control in freshwater teleost fish.
Assuntos
Peixes/fisiologia , Células Intersticiais do Testículo/enzimologia , Células Intersticiais do Testículo/ultraestrutura , Espermatogênese , 3-Hidroxiesteroide Desidrogenases/metabolismo , Fosfatase Ácida/metabolismo , Animais , Água Doce , Lisossomos/enzimologia , Masculino , Microscopia Eletrônica de TransmissãoRESUMO
The testosterone levels with nasal gland volume and Leydig cell morphometry in sexually mature capybaras were compared using 10 adult capybaras, aging 28 months. Body and testicular weight were 50kg and 28g, respectively. The gonadosomatic index was 0.11±0.02 percent, while nasal gland volume was 34.12±13.04ml. Serum testosterone concentration was 25.07±14.73ng/ml. Leydig cell volume density and leydigosomatic index were, respectively, 28.8±8.3 percent and 0.030±0.007 percent. Total and individual Leydig cell volumes were 6.88±1.92ml and 2,228.14±272.59x10-12ml, respectively. Leydig cell numbers per testis and per gram of testis were, respectively, 3,079.4±719.9x10(6) and 115.09±31.78x10(6) cells. These results show that increase in serum testosterone concentration is correlated to a proportional increase of nasal gland and Leydig cell volume in capybaras.
Estimaram-se as correlações entre os níveis de testosterona e o volume da glândula nasal e a morfometria das células de Leydig no parênquima testicular de capivaras sexualmente maduras. Utilizaram-se 10 capivaras com aproximadamente 28 meses de idade e com peso médio corporal de 50kg e testicular de 28g. O índice gonadossomático e o volume médio da glândula nasal foram 0,11±0,02 por cento e 34,12±13,04ml, respectivamente, e a concentração sérica de testosterona 25,07±14,73ng/ml. A proporção volumétrica de células de Leydig e o índice leydigossomático foram 28,8± 8,3 por cento e 0,030±0,007 por cento, respectivamente. Os volumes total e individual de células de Leydig foram 6,88±1,92ml e 2228,14±272,59´10-12ml, respectivamente. O número de células de Leydig por testículo e por grama de testículo foram, respectivamente, 3079,4±719,9´10(6) e 115,09±31,78´10(6). Concluiu-se que o aumento dos níveis séricos de testosterona foi acompanhado por aumento proporcional do volume da glândula nasal de capivaras e que a concentração desse hormônio é tanto mais alta quanto maior for o volume da célula de Leydig.
Assuntos
Animais , Células Intersticiais do Testículo/ultraestrutura , Roedores , Testosterona/efeitos adversosRESUMO
The testosterone levels with nasal gland volume and Leydig cell morphometry in sexually mature capybaras were compared using 10 adult capybaras, aging 28 months. Body and testicular weight were 50kg and 28g, respectively. The gonadosomatic index was 0.11±0.02%, while nasal gland volume was 34.12±13.04ml. Serum testosterone concentration was 25.07±14.73ng/ml. Leydig cell volume density and leydigosomatic index were, respectively, 28.8±8.3% and 0.030±0.007%. Total and individual Leydig cell volumes were 6.88±1.92ml and 2,228.14±272.59x10-12ml, respectively. Leydig cell numbers per testis and per gram of testis were, respectively, 3,079.4±719.9x106 and 115.09±31.78x106 cells. These results show that increase in serum testosterone concentration is correlated to a proportional increase of nasal gland and Leydig cell volume in capybaras.(AU)
Estimaram-se as correlações entre os níveis de testosterona e o volume da glândula nasal e a morfometria das células de Leydig no parênquima testicular de capivaras sexualmente maduras. Utilizaram-se 10 capivaras com aproximadamente 28 meses de idade e com peso médio corporal de 50kg e testicular de 28g. O índice gonadossomático e o volume médio da glândula nasal foram 0,11±0,02% e 34,12±13,04ml, respectivamente, e a concentração sérica de testosterona 25,07±14,73ng/ml. A proporção volumétrica de células de Leydig e o índice leydigossomático foram 28,8± 8,3% e 0,030±0,007%, respectivamente. Os volumes total e individual de células de Leydig foram 6,88±1,92ml e 2228,14±272,59´10-12ml, respectivamente. O número de células de Leydig por testículo e por grama de testículo foram, respectivamente, 3079,4±719,9´106 e 115,09±31,78´106. Concluiu-se que o aumento dos níveis séricos de testosterona foi acompanhado por aumento proporcional do volume da glândula nasal de capivaras e que a concentração desse hormônio é tanto mais alta quanto maior for o volume da célula de Leydig.(AU)