Tissue alterations in the Guinea pig lateral prostate following antiandrogen flutamide therapy

The flutamide antiandrogenic effects on the Guinea pig male prostate morphology in puberal, post-puberal and adult ages were evaluated in the present study. Daily-treated group animals received flutamide subcutaneous injection at a dose of 10 mg/Kg body weight for 10 days. The control group animals received a pharmacological vehicle under the same conditions. The lateral prostate was removed, fixed and processed for light and transmission electron microscopy. The results revealed an increase of the acinus diameter in the treated puberal animals and straitness in the stromal compartment around the acini. The epithelial cells exhibited cubic phenotype. In the post-puberal and adult animals, a decrease of the acinus diameter was observed, as well as an increase of the smooth muscle layer and presence of the folds at epithelium. The ultrastructural evaluation of the secretory cells in the treated group demonstrated endomembrane enlargement, mainly in the rough endoplasmic reticulum and Golgi apparatus. In addition, a decrease of the microvilli and alterations in the distribution patterns and density of the stromal fibrillar components were observed. In conclusion, the flutamide treatment exerts tissue effects on the lateral prostate, promoting stroma/epithelium alterations.

Apoptogenic effect of the lipophilic o-naphthoquinone CG 10-248 on rat hepatocytes: light and electron microscopy studies

CG 10-248 (3,4-dihydro-2,2-dimethyl-9-chloro-2H-naphtho[1,2b]pyran-5,6-dione; CG-NQ), a beta-lapachone analogue, modified the ultrastructure of rat hepatocytes, as demonstrated by light and electron microscopy. After 4 h incubation with 100 microM CG-NQ, the following effects were observed: (a) nuclear chromatin condensation; (b) chromatin fragmentation; (c) displacement of mitochondria, concentrated around the nucleus; (d) disruption or expansion of mitochondrial outer or inner membranes, respectively; (e) displacement and alteration of endoplasmic reticulum (rough and smooth); (f) decrease of microvilli; (g) blebbing of plasma membrane and production of apoptotic bodies formed by folding of plasma membrane fragments around mitochondria or peroxysomes; and (h) production of hydrogen peroxide. Expression of such effects varied according to hepatocyte samples and taken together strongly support an apoptotic action of CG-NQ dependent on reactive oxygen species.

Quantitative ultrastructural changes induced by sucrose administration in the pancreatic B cells of normal hamsters

We have previously reported that young male Syrian hamsters receiving a sucrose-rich diet presented increased B-cell replication rate and size. The aim of the present study was to analyze, under the same experimental conditions, the ultrastructural changes in B cells. For this purpose, young male Syrian hamsters were fed with a commercial diet and 10 sucrose in their drinking water (S group) while the control group (C) received the same diet and tap water, for 5 weeks. Samples of the pancreas removed after that period were processed for the immunohistochemical identification of B cells as well as for measuring several ultrastructural parameters. S hamsters showed higher serum insulin levels, while similar serum glucose values were obtained in animals from both groups. The B cells from S group exhibited lesser number of dense secretory granules at expenses of an increase of the pale ones, increased number of both exocytosis profiles and fusion-granule images, as well as enlargement of the intercellular space and mitochondrial area. Marked expansions of this space, limited by junctional complexes, were observed between adjacent B cells. These results would indicate that sucrose administration to normal hamsters not only increases the pancreatic B-cell mass but also induces measurable subcellular changes in the individual B-cell characteristic of an enhanced secretory activity. The present model would represent a useful tool for testing strategies in preventing the damage or promoting the recovery of the pancreatic B cells.

Scanning electron microscopy of acinar cells of rat submandibular salivary glands

1. The submandibular salivary gland of rats was observed by high-resolution scanning electron microscopy employing the aldehyde-osmium-DMSO-osmium method. 2. The intracellular membranous components and sponge-like structures of basement membrane containing the fine collagen fibrils of acinar cells were clearly identified in three dimensional images. The granular endoplasmic reticulum and Golgi apparatus showed the luminal surface. The mitochondria were small, ranging in diameter from 0.3 to 0.5 µm, and revealed their cristae. The secretory granules ranged in diameter from 0.3 to 1.4 µm. ribosome granules were attached to the surfaces of cisterns, and measured 20 to 25 nm in diameter. 3. The contact areas between the acinar cells revealed numerous cytoplasmic protrusions. In the striated duct cells, the mitochondria were arranged vertically and surrounded by nasal infoldings of the plasma membranes. At high magnification, the mitochondrial cristae were visualized in their three-dimensional characteristics

Ultrastructural characteristics of the endometrial stroma of athymic nude rats in the proestrus and metestrus phases of the estrous cycle

En el presente estudio se observa la ultraestructura del estroma endometrial de ratas congenitamente atímicas (rnu/rnu), homozigotas para el gen nude recesivo y de sus camadas eutímicas (+/rnu), heterozigotas para el mismo gen, ambas de la línea Rowet, con el propósito de detectar posibles alteraciones en las ratas rnu/rnu. Estudios morfológicos del aparato reproductor de éstas, usando microscopio de luz, no muestran diferencias de las ratas +/rnu. Estudios ultraestructurales referentes a este asunto no fueron encontrados en la literatura consultada. La ultraestructura del estroma endometrial de rnu/rnu y +/rnu mostraron fibroblastos con una GER más dilatada en el proestro que el metaestro y una menor frecuencia de eosinófilos y macrófagos en las ratas rnu/rnu que en las +/rnu en proestro. La frecuencia de monocitos fue mas alta en el proestro mientras que la de los neutrófilos fue mas baja en el proestro y metaestro, en ambos grupos de ratas. Los resultados ultraestructurales sugieren que la menor frecuencia de eosinófilos y macrófagos encontrados en la ratas rnu/rnu en fase de proestro pueden estar relacionados con atmia congénita y/o alteraciones en los niveles de hormonas esteroidales encontradas en esas ratas

Ultrastructure of the ovary of Dermatobia hominis (Diptera: cuterebridae). II. Origin of the tunica propria in ovarioles

Ovaries up to the 8th day pupae of Dermatobia hominis were studied by transmission electron microscopy. Ovarioles were recognized in ovaries of 4-day old pre-pupae, surrounded by a thin tunica propria of acellular fibrilar material similar in structure to the internal portion of the external tunica of the ovary. There is continuity of the tunica propria and the ovarian tunica, indicating that the former structure originates from the tunica externa. In 5 to 7-day pupae the interstitial somatic cells from the apical region of the ovary, close to the ovarioles, show delicate filamentous material inside of their rough endoplasmic reticulum cisternae; similar material is seem among these cells. Our observations suggest that interstitial somatic cells do not originate the tunica propria but contribute to its final composition

Structural and cytochemical localization of the endoplasmic reticulum in the electrocyte of electrophorus electricus

Vesículas com vários diâmetros variando entre 0.06 e 0.6 micronm e localizadas em torno do núcleo, bem como na proçäo mais periférica, foram observadas no electrócito do peixe elétrico Electrophorus electricus. Tais vesículas foram consideradas como componentes de retículo endoplasmático do eletrócito uma vez que observaçöes citoquímicas demonstraram a presença de glicose-6-fosfatase na membrana dessas vesículas. Esta idéia é reforçada por resultados obtidos com o uso da técnica do pirantiminiato de potássio e análise espectroscópica de elétrons, que mostrou a presença da Ca++ na membrana das vesiculas