Mitochondrial alterations and apoptosis in smooth muscle from aged rats.

We studied changes in mitochondrial morphology and function in the smooth muscle of rat colon. Under confocal microscopy, tissues loaded with potentiometric dye displayed rapid and spontaneous depolarization. Cyclosporin A (CsA), inhibitor of the permeability transition pore (PTP), caused an increase in mitochondrial membrane potential (DeltaPsim) in tissues from adult young animals. In aged rats these changes were not observed. This suggests that physiological activation of PTP in aged rats is reduced. Electron microscopy showed alterations of the mitochondrial ultrastructure in tissues from aged rats involving a decreased definition of the cristae and fragmentation of the mitochondrial membranes. We also detected an increase in apoptotic cells in the smooth muscle from aged animals. Our results show that the aging process changes PTP activity, the ability to maintain DeltaPsim and mitochondrial morphology. It is suggested that these can be associated with mitochondrial damage and cell death.

Habitual exercise program protects murine intestinal, skeletal, and cardiac muscles against aging.

Aging and aerobic exercise are two conditions known to interfere with health and quality of life, most likely by inducing oxidative stress to the organism. We studied the effects of aging on the morphological and functional properties of skeletal, cardiac, and intestinal muscles and their corresponding oxidative status in C57BL/6 mice and investigated whether a lifelong moderate exercise program would exert a protective effect against some deleterious effects of aging. As expected, aged animals presented a significant reduction of physical performance, accompanied by a decrease of gastrocnemius cross-sectional area and cardiac hypertrophy. However, most interesting was that aging dramatically interfered with the intestinal structure, causing a significant thickening of the ileum muscular layer. Senescent intestinal myocytes displayed many mitochondria with disorganized cristae and the presence of cytosolic lamellar corpuscles. Lipid peroxidation of ileum and gastrocnemius muscle, but not of the heart, increased in aged mice, thus suggesting enhanced oxidative stress. With exception of the intestinal muscle responsiveness, animals submitted to a daily session of 60 min, 5 days/wk, at 13 up to 21 m/min of moderate running in treadmill during animal life span exhibited a reversion of all the observed aging effects on intestinal, skeletal, and heart muscles. The introduction of this lifelong exercise protocol prevented the enhancement of lipid peroxidation and sarcopenia and also preserved cellular and ultracellular structures of the ileum. This is the first time that the protective effect of a lifelong regular aerobic physical activity against the deleterious effects of aging on intestinal muscle was demonstrated.

Enhancement of lindane-induced liver oxidative stress and hepatotoxicity by thyroid hormone is reduced by gadolinium chloride.

The role of Kupffer cells in the hepatocellular injury and oxidative stress induced by lindane (20 mg/kg; 24h) in hyperthyroid rats (daily doses of 0.1 mg L-3,3',5-triiodothyronine (T3)/kg for three consecutive days) was assessed by the simultaneous administration of gadolinium chloride (GdCl3; 2 doses of 10mg/kg on alternate days). Hyperthyroid animals treated with lindane exhibit enhanced liver microsomal superoxide radical (O2.-) production and NADPH cytochrome c reductase activity, with lower levels of cytochrome P450, superoxide dismutase (SOD) and catalase activity, and glutathione (GSH) content over control values. These changes are paralleled by a substantial increase in the lipid peroxidation potential of the liver and in the O2.- generation/ SOD activity ratio, thus evidencing a higher oxidative stress status that correlates with the development of liver injury characterized by neutrophil infiltration and necrosis. Kupffer cell inactivation by GdCl3 suppresses liver injury in lindane/T3-treated rats with normalization of altered oxidative stress-related parameters, excepting the reduction in the content of GSH and in catalase activity. It is concluded that lindane hepatotoxicity in hyperthyroid state, that comprises an enhancement in the oxidative stress status of the liver, is largely dependent on Kupffer cell function, which may involve generation of mediators leading to pro-oxidant and inflammatory processes.

Ultrastructural and immunohistochemical analysis of proteoglycans in mouse pubic symphysis.

Proteoglycans were accurately localized in mouse pubic symphyseal tissues using the cuprolinic blue method. Specific glycosaminoglycans degradative enzymes, together with chondroitin sulfate and decorin antibodies, allowed the identification of glycosaminoglycans. Chondroitin sulfate proteoglycans were the main proteoglycans observed in hyaline cartilage, fibrocartilage, and dense connective tissue. Ultrastructurally, they were seen as electron-dense granules and filaments. The granules, rich in chondroitin sulfate chains, were exclusively found in hyaline cartilage, whereas filaments were present in cartilage, fibrocartilage, and dense connective tissue. The latter were classified by size and susceptibility to enzyme digestion into F1, F2 and F3 filaments: F1 filaments were small, thin, and collagen fibril-associated; F2 filaments were thick, heavily stained, and localized around individual collagen fibrils and between bundles of collagen fibrils; and F3 filaments were scattered throughout elastic fiber surfaces. Considering their localization, susceptibility to chondroitinase AC and immunohistochemical detection, the symphysial F1 filaments were found to be preferentially decorin substituted with chondroitin sulfate side chains. The F2 filaments were also susceptible to chondroitinase AC treatment, whereas F3 filaments could be digested by heparitinase. The data thus obtained on the localization and identification of pubic symphyseal proteoglycans in virgin mice may be useful in the study of structural modifications that occur throughout pregnancy.

Estrous cycle of athymic nude rats

En el presente trabajo intentamos establecer las fases y duración del ciclo estral de ratas congénitamente atímicas (rnu/rnu), homocigotas para el gen recesivo nude y de sus littermates autímicas (rnu/+), heterocigotas para el mismo gen, ambas de la línea Rowet, ya que las ratas rnu/rnu presentan menor capacidad de reproducción que las rnu/+. El análisis del frotis vaginal, reveló tanto para las ratas rnu/rnu, como para las rnu/+, un ciclo estral con cino dias de duración. siendo dos días consecutivos de diestro. Tampoco observamos diferencias citológicas entre las fases del ciclo estral en ambos tipos de ratas. Verificamos en la fase de estro un predominio de células acidófilas disponiéndose, generalmente, en grumos groseros. En el metaestro pudimos notar células acidófilas, células basófilas y leucocitos. Sin embargo, el diestro fue caracterizado por la presencia de mucus, innumerables leucocitos y escasas células acidófilas y cianófilas, nucleadas en su mayoría, a veces disponiéndose en grumos. Se sabe que las oscilaciones estructurales del epitelio vaginal, observadas en la colpocitopatología, son regidas por hormonas. Como datos preliminares, sobre los niveles séricos de esteroides de ratas rnu/+ y rnu/rnu, mostraron alteraciones en estas últimas, parece razonable suponer que mecanismos fisiológicos y hormonales desconocidos e inherentes a estos organismos atímicos, puedan mantener normal el ciclo estral de estos animales nude

Morphological aspects of the ovary of athymic nude rats in the proestrus and metestrus phases of the estrous cycle

En el presente trabajo analizamos, a nivel de microscopía de luz, la morfología del ovario de ratas congenitamente atímicas (rnu/rnu) homocigotas para gen nude y la de sus littermates eutímicas (rnu+), heterocigotas para el mismo gen, de la línea Rowett, en las fases de proestro y de metaestro del ciclo estral. Pudimos observar que la morfología del ovario de ratas atímicas, en las dos fases estudiadas, es semejante a la presentada por las eutímicas y compatible con la morfología del ovario de ratas de otras líneas descritas en la literatura

Aspectos morfológicos do epitélio uterino de ratas nude atímicas nas fases de proestro e de metaestro do ciclo estral / Morphological characteristics of the uterine epithelium of athimic nude rats, in the proestrus and metestrus phases of estrous cycle

O presente experimento compara a nível de microscopia de luz a morfologia do epitélio uterino de ratas congenitamente atímicas (rnu/rnu) com a de suas "littermtes" eutímicas (rnu/ +), da linhagen Rowett, nas fases de proestro e de metaestro do ciclo estral. Pudemos observar que a morfologia do epitélio uterino das ratas homozigotas (rnu/rnu) foi semelhante à das heterozigotas (rnu/ +), em ambas as fases estudadas e compatível com a morfologia uterina descrita na literatura referente a ratas comuns. No metaestro verificamos epitélio do tipo cilíndrico simples e áreas deste epitélio em desarranjo com algumas das células apresentando vacuolizaçäo citoplasmática e núcleo picnótico. No proestro, o epitélio cilíndrico simples apresentou-se constituído por células contendo núcleo alongado deslocado para a porçäo basal

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

Aspectos ultra-estruturais do epitélio da tuba uterina humana durante o ciclo menstrual / Ultrastructural aspects of the human uterine tube epithelium during menstrual cycle

Objetivo do estudo: Os autores analisam, através de microscopia eletrônica de transmissäo, o epitélio da tuba uterina humana, durante o ciclo menstrual. Tipo de estudo: Prospectiva, experimental. Local: Escola Paulista de Medicina. Pacientes: Estudaram-se quatro pacientes eumenorréicas, multíparas, duas na fase proliferativa e duas na fase secretora do ciclo. Intervençöes: Foram submetidas à salpingectomia bilateral, por apresentarem alto risco reprodutivo. Medidas e resultados: Avaliaram, quanto à ultra-estrutura, o epitélio das regiöes do istmo, da ampola e do infundíbulo. Verificaram que, na fase proliferativa, a superfície epitelial mostra-se uniforme em toda a sua extensäo; na fase secretora, apresenta-se irregular no istmo e na ampola. Identificaram dois tipos de células: ciliadas e näo ciliadas ou secretoras. As células secretoras apresentam durante o ciclo modificaçöes ultra-estruturais mais pronunciadas do que as ciliadas. Na fase lútea, as células secretoras possuem retículo endoplasmático e aparelho de Golgi bem desenvolvidos e dilatados, bem como numerosas vesículas eletrolúcidas. Verificaram, também, que na segunda fase do ciclo a célula ...