A low dose of benzo(a)pyrene during prepuberty in male rats generated immediate oxidative stress in the testes and compromised steroidogenic enzymes/proteins.

The prepubertal period is crucial for sexual development and any alterations can interfere with the reproductive system in adulthood. The aim of this study was to evaluate how Benzo(a)pyrene (BaP) can affect the testes during the prepubertal period. Juvenile male Wistar rats were divided into a control (corn oil + DMSO) and a BaP-group (0.1 µg/kg/day), exposed to BaP for 31 days (gavage), and all parameters were evaluated on postnatal day (PND) 54. Leukocyte counts were decreased. Histological analyses of the testes revealed that height and seminiferous tubules diameters (STDs) were reduced, tubular dynamics were altered, and Leydig cell atrophy was evident in the BaP-group. The testosterone concentration was decreased while FSH levels increased within the BaP-exposed group. Steroidogenic enzymes in the testes were decreased, but steroidogenic acute regulatory protein was not altered. The expression of gstp1 and ckit enzymes was decreased. Reduced glutathione (GSH) and superoxide dismutase (SOD) were increased, whereas malondialdehyde (MDA) was decreased in the testes. In conclusion, BaP or its metabolites causes low systemic toxicity; however, it adversely influences testicular function by disrupting the hormonal axis, unbalancing testicular antioxidative, and blocking the action of the steroidogenic mechanisms.

Perinatal exposure to insecticide fipronil: effects on the reproductive system in male rats.

Fipronil is an insecticide widely used in agriculture, veterinary medicine and public health that has recently been listed as a potential endocrine disrupter. In the present study we evaluated the effects of perinatal exposure to fipronil during the period of sexual brain differentiation and its later repercussions on reproductive parameters in male rats. Pregnant rats were exposed (via gavage) to fipronil (0.03, 0.3 or 3mgkg-1) from Gestational Day 15 until Postnatal Day 7. Fipronil exposure did not compromise the onset of puberty. In adulthood, there was no effect on organ weight or sperm production. Furthermore, there were no adverse effects on the number of Sertoli cells per seminiferous tubule, testicular and epididymal histomorphometry or histopathology or expression patterns of androgen receptor in the testis. Similarly, no changes were observed in the sexual behaviour or hormone levels. However, in rats exposed to fipronil, changes in sperm motility were observed, with a decrease in motile spermatozoa and an increase in non-mobile spermatozoa, which can compromise sperm quality in these rats. Perinatal exposure to fipronil has long-term effects on sperm parameters, and the epididymis can be a target organ. Additional studies should be undertaken to identify the mechanisms by which fipronil affects sperm motility.

Apoptosis is triggered by melatonin in an in vivo model of ovarian carcinoma.

Apoptosis plays an important role in the treatment of cancer, and targeting apoptosis-related molecules in ovarian cancer (OC) is of great therapeutic value. Melatonin (Mel) is an indoleamine displaying several anti-cancer properties and has been reported to modulate apoptosis signaling in multiple tumor subtypes. We investigated OC and the role of Mel therapy on the pro-apoptotic (p53, BAX, caspase-3, and cleaved caspase-3) and anti-apoptotic (Bcl-2 and survivin) proteins in an ethanol (EtOH)-preferring rat model. To induce OC, the left ovary was injected directly with a single dose of 100 µg 7,12-dimethylbenz(a)anthracene dissolved in 10 µl of sesame oil under the bursa. Right ovaries were used as sham-surgery controls. After developing OC, half of the animals received i.p. injections of Mel (200 µg/100 g BW per day) for 60 days. Body weight gain, EtOH consumption, and energy intake were unaffected by the treatments. Interestingly, absolute and relative OC masses showed a significant reduction after Mel therapy, regardless of EtOH consumption. To accomplish OC-related apoptosis, we first observed that p53, BAX, caspase-3, and cleaved caspase-3 were downregulated in OC tissue while Bcl-2 and survivin were overexpressed. Notably, Mel therapy and EtOH intake promoted apoptosis along with the upregulation of p53, BAX, and cleaved caspase-3. Fragmentation of DNA observed by TUNEL-positive nuclei was also enhanced following Mel treatment. In addition, Bcl-2 was downregulated by the EtOH intake and lower survivin levels were observed after Mel therapy. Taken together, these results suggest that Mel induce apoptosis in OC cells of EtOH-preferring animals.

Melatonin attenuates the TLR4-mediated inflammatory response through MyD88- and TRIF-dependent signaling pathways in an in vivo model of ovarian cancer.

BACKGROUND: Toll-like receptors (TLRs) are effector molecules expressed on the surface of ovarian cancer (OC) cells, but the functions of the TLR2/TLR4 signaling pathways in these cells remain unclear. Melatonin (mel) acts as an anti-inflammatory factor and has been reported to modulate TLRs in some aggressive tumor cell types. Therefore, we investigated OC and the effect of long-term mel therapy on the signaling pathways mediated by TLR2 and TLR4 via myeloid differentiation factor 88 (MyD88) and toll-like receptor-associated activator of interferon (TRIF) in an ethanol-preferring rat model. METHODS: To induce OC, the left ovary of animals either consuming 10% (v/v) ethanol or not was injected directly under the bursa with a single dose of 100 µg of 7,12-dimethylbenz(a)anthracene (DMBA) dissolved in 10 µL of sesame oil. The right ovaries were used as sham-surgery controls. After developing OC, half of the animals received i.p. injections of mel (200 µg/100 g b.w./day) for 60 days. RESULTS: Although mel therapy was unable to reduce TLR2 levels, it was able to suppress the OC-associated increase in the levels of the following proteins: TLR4, MyD88, nuclear factor kappa B (NFkB p65), inhibitor of NFkB alpha (IkBα), IkB kinase alpha (IKK-α), TNF receptor-associated factor 6 (TRAF6), TRIF, interferon regulatory factor 3 (IRF3), interferon ß (IFN-ß), tumor necrosis factor alpha (TNF-α), and interleukin (IL)-6. In addition, mel significantly attenuated the expression of IkBα, NFkB p65, TRIF and IRF-3, which are involved in TLR4-mediated signaling in OC during ethanol intake. CONCLUSION: Collectively, our results suggest that mel attenuates the TLR4-induced MyD88- and TRIF-dependent signaling pathways in ethanol-preferring rats with OC.

Maternal protein restriction during pregnancy affects gene expression and immunolocalization of intestinal nutrient transporters in rats.

Intrauterine dietary restriction may cause changes in the functioning of offspring organs and systems later in life, an effect known as fetal programming. The present study evaluated mRNA abundance and immunolocalization of nutrient transporters as well as enterocytes proliferation in the proximal, median and distal segments of small intestine of rats born to protein-restricted dams. Pregnant rats were fed hypoproteic (6% protein) or control (17% protein) diets, and offspring rats were evaluated at 3 and 16 weeks of age. The presence of SGLT1 (sodium-glucose co-transporter 1), GLUT2 (glucose transporter 2), PEPT1 (peptide transporter 1) and the intestinal proliferation were evaluated by immunohistochemical techniques and the abundance of specific mRNA for SGLT1, GLUT2 and PEPT1 was assessed by the real-time PCR technique. Rats born to protein-restricted dams showed higher cell proliferation in all intestinal segments and higher gene expression of SGLT1 and PEPT1 in the duodenum. Moreover, in adult animals born to protein-restricted dams the immunoreactivity of SGLT1, GLUT2 and PEPT1 in the duodenum was more intense than in control rats. Taken together, the results indicate that changes in the small intestine observed in adulthood can be programmed during the gestation. In addition, they show that this response is caused by both up-regulation in transporter gene expression, a specific adaptation mechanism, and intestinal proliferation, an unspecific adaptation mechanism.

Chronic ethanol consumption alters all-trans-retinoic acid concentration and expression of their receptors on the prostate: a possible link between alcoholism and prostate damage.

BACKGROUND: Ethanol (EtOH) alters the all-trans-retinoic acid (ATRA) levels in some tissues. Retinol and ATRA are essential for cell proliferation, differentiation, and maintenance of prostate homeostasis. It has been suggested that disturbances in retinol/ATRA concentration as well as in the expression of retinoic acid receptors (RARs) contribute to benign prostate hyperplasia and prostate cancer. This study aimed to evaluate whether EtOH consumption is able to alter retinol and ATRA levels in the plasma and prostate tissue as well as the expression of RARs, cell proliferation, and apoptosis index. METHODS: All animals were divided into 4 groups (n = 10/group). UChA: rats fed 10% (v/v) EtOH ad libitum; UChACo: EtOH-naïve rats without access to EtOH; UChB: rats fed 10% (v/v) EtOH ad libitum; UChBCo: EtOH-naïve rats without access to EtOH. Animals were euthanized by decapitation after 60 days of EtOH consumption for high-performance liquid chromatography and light microscopy analysis. RESULTS: EtOH reduced plasma retinol concentration in both UChA and UChB groups, while the retinol concentration was not significantly different in prostate tissue. Conversely, plasma and prostate ATRA levels increased in UChB group compared with controls, beyond the up-regulation of RARß and -γ in dorsal prostate lobe. Additionally, no alteration was found in cell proliferation and apoptosis index involving dorsal and lateral prostate lobe. CONCLUSIONS: We conclude that EtOH alters the plasma retinol concentrations proportionally to the amount of EtOH consumed. Moreover, high EtOH consumption increases the concentration of ATRA in plasma/prostate tissue and especially induces the RARß and RARγ in the dorsal prostate lobe. EtOH consumption and increased ATRA levels were not associated with cell proliferation and apoptosis in the prostate.

Ultrastructure of the epithelium lining of cauda epididymidis in mongrel dogs / Ultraestrutura do epitélio de revestimento da cauda epididimária em cães sem raça definida

The epithelium lining of cauda epididymidis in mongrel dogs was examined by transmission electron microscopy. The epididymal epithelium is pseudostratified with stereocilia and is composed predominantly of principal and clear cells. Therefore, exist basal and apical cells. The principal and clear cells show features suggesting that they may be preferentially involved in absorptive and secretive functions. These results are compared with previously published data on the cauda epididymidis of other mammalian species, in order to understand the significance of the epididymis in sperm maturation.(AU)

O epitélio de revestimento da cauda epididimária em cães sem raça definida foi examinado através da microscopia eletrônica de transmissão. O epitélio epididimário é pseudoestratificado com estereocílios na borda luminal e é composto principalmente por células principais e claras. Além destes tipos, foi observado algumas células basais e apicais. As células principais e claras apresentaram características ultra-estruturais que sugerem que as mesmas estão envolvidas com funções absortivas e secretórias. Os resultados foram comparados com estudos prévios realizados na cauda do ducto epididimário de outros mamíferos, com o objetivo de melhor entender o papel do epidídimo na maturação espermática.(AU)

Variations in maternal care alter corticosterone and 17beta-estradiol levels, estrous cycle and folliculogenesis and stimulate the expression of estrogen receptors alpha and beta in the ovaries of UCh rats.

BACKGROUND: Variations in maternal care are associated with neonatal stress, hormonal disturbances and reproductive injuries during adulthood. However, the effects of these variations on sex hormones and steroid receptors during ovary development remain undetermined. This study aimed to investigate whether variations in maternal care are able to influence the hormonal profile, follicular dynamics and expression of AR, ER-alpha and ER-beta in the ovaries of UCh rat offspring. METHODS: Twenty-four adult UCh rats, aged 120 days, were randomly divided into two groups (UChA and UChB) and mated. Maternal care was assessed from birth (day 0) to the 10th postnatal day (PND). In adulthood, twenty adult female rats (UChA and UChB offspring; n = 10/group), aged 120 days, were euthanized by decapitation during the morning estrus. RESULTS: UChA females (providing high maternal care) more frequently displayed the behaviors of carrying pups, as well as licking/grooming and arched back nursing cares. Also, mothers providing high care had elevated corticosterone levels. Additionally, offspring receiving low maternal care showed the highest estrous cycle duration, increased corticosterone and 17beta-estradiol levels, overexpression of receptors ER-alpha and ER-beta, increased numbers of primordial, antral and mature follicles and accentuated granulosa cell proliferation. CONCLUSIONS: Our study suggests that low maternal care alters corticosterone and 17beta-estradiol levels, disrupting the estrous cycle and folliculogenesis and differentially regulating the expression of ER-alpha and ER-beta in the ovaries of adult rats.

Long-term exogenous melatonin treatment modulates overall feed efficiency and protects ovarian tissue against injuries caused by ethanol-induced oxidative stress in adult UChB rats.

BACKGROUND: Chronic ethanol intake leads to reproductive damage including reactive oxygen species formation, which accelerates the oxidative process. Melatonin is known to regulate the reproductive cycle, food/liquid intake, and it may also act as a potent antioxidant indoleamine. The aim of this study was to verify the effects of alcoholism and melatonin treatment on overall feed efficiency and to analyze its protective role against the oxidative stress in the ovarian tissue of UChB rats (submitted to 10% [v/v] voluntary ethanol consumption). METHODS: Forty adult female rats (n = 10/group) were finally selected for this study: UChB Co: drinking water only; and UChB EtOH: drinking ethanol at 2 to 6 ml/100 g/d + water, both receiving 0.9% NaCl + 95% ethanol 0.04 ml as vehicle. Concomitantly, UChB Co + M and UChB EtOH + M groups were infused with vehicle + melatonin (100 µg/100 g body weight/d) intraperitoneally over 60 days. All animals were euthanized by decapitation during the morning estrus (4 am). RESULTS: Body weight gain was reduced with ethanol plus melatonin after 40 days of treatment. In both melatonin-treated groups, it was observed a reduction in food-derived calories and liquid intake toward the end of treatment. The amount of consumed ethanol dropped during the treatment. Estrous cycle was longer in rats that received both ethanol and melatonin, with prolonged diestrus. Following to oxidative status, lipid hydroperoxide levels were higher in the ovaries of ethanol-preferring rats and decreased after melatonin treatment. Additionally, antioxidant activities of superoxide dismutase, glutathione peroxidase activity, and glutathione reductase activity were increased in melatonin-treated groups. CONCLUSIONS: We suggest that melatonin is able to affect feed efficiency and, conversely, it protects the ovaries against the oxidative stress arising from ethanol consumption.

Functional and morphological reproductive aspects in male rats exposed to di-n-butyl phthalate (DBP) in utero and during lactation.

The potential adverse reproductive effects, with emphasis on the epididymis, of in utero and lactational exposure to 100 mg/kg/d di-n-butyl phthalate (DBP) in adult male rat offspring were investigated. The fetal testis histopathology was also determined. The selected endpoints included reproductive organ weights, sperm motility and morphology, sperm epididymal transit time, sperm quantity in the testis and epididymis, hormonal status, fetal testis and epididymal histopathology and stereology, and androgen receptor (AR), aquaporin 9 (AQP9), and Ki-67 immunoreactivities. Pregnant females were divided into two groups: control (C) and treated (T). The treated females received DBP (100 mg/kg/d, by gavage) from gestation day (GD) 12 to postnatal day (PND) 21, while control dams received the vehicle. Some pregnant dams were killed by decapitation on GD20, and testes from male fetuses were collected for histopathogy. Male rats from other dams were killed at PND 90. Fetal testes from treated group showed Leydig-cell clusters, presence of multinucleated germinative cells, and increase of the interstitial component. Testosterone levels and reproductive organ weights were similar between the treated and control adult groups. DBP treatment did not markedly affect relative proportions of epithelial, stromal, or luminal compartments in the epididymis; sperm counts in the testis and epididymis; sperm transit time; or sperm morphology and motility in adult rats. The AR and AQP9 immunoreactivities and proliferation index were similar for the two groups. These results showed that fetal testes were affected by DBP as evidenced by testicular histopathologic alterations, but reproductive parameters and epididymal structure/function were not significantly altered in the adult animals exposed to 100 mg/kg DBP in utero and during lactation.

Estrous cycle, anatomy and histology of the uterine tube of the mongolian gerbil meriones unguiculatus

Fue clasificado el ciclo estral del gerbo de Mongolia y descritas las estructuras y relaciones de la tuba uterina en la cavidad abdomino-pélvica, así como la histología de su epitelio de revestimiento. Las tubas uterinas de 19 hembras adultas del gerbo de Mongolia fueron investigadas a través de técnicas de anatomía e histología. Fue observado el ciclo estral poliéstrico e irregular, con cinco fases: proestro, estro I, estro II, metaestro y diestro. El estro I se caracterizaba por presentar células queratinizadas, esparcidas y en menor número con respecto al estro II. La tuba uterina presentaba relaciones con la extremidad distal del cuerno uterino y con el ovario. La tuba presenta serosa de revestimiento externo (lámina visceral del peritoneo), túnica media muscular de fibras circulares lisas y túnica mucosa con epitelio de revestimiento simple, constituido de células cilíndricas ciliadas y secretoras. Anatómicamente las tubas uterinas, se dividen en cuatro regiones: intramural, istmo, ampolla e infundíbulo. El gerbo no constituye modelo ideal para estudios del ciclo estral debido a su irregularidad. La anatomía e histología de la tuba uterina son semejantes a la presentada por los roedores usados como animales de laboratorio

Scanning electron microscopic study of the tongue of chinchila

A través de la microscopía electrónica de barrido se observó la estructura tridimensional de las papilas linguales y el tejido conectivo de la lengua de chinchilla. Se utilizó la técnica de maceración celular con NaOH para remover la capa epitelial y visualizar la arquitectura del tejido conectivo. El dorso de la lengua está cubierto por epitelio escamoso estratificado querantizado y posee cuatro tipos de papilas: filiformes, fungiformes, foliadas y valadas. Las imágenes de microscopía de barrido mostraron superficies de las células epiteliales con micropuentes distintos de los bordes intercelulares y poros linguales. El tejido conectivo central de las papilas filiformes de las partes anterior e intermedia de la lengua, presentaban dos o tres protrusiones semejantes a vástagos, mientras que en la parte posterior se observó una amplia base con varias protrusiones apicales. La lámina propia de las papilas fungiformes era columnar y las papilas valadas presentaron una muesca central rodeada por numeroso tejido conectivo papilar, las papilas foliadas presentaban orificios elípticos rodeados por escaso tejido conectivo papilar

Light and scanning electron microscopic study of the vallate papillae of the opossum (didelphis albiventris)

Las características morfológicas del epitelio y tejido conjuntivo de las papilas valadas del oposum fueron observadas a través de los microscopios de luz y electrónico de barrido. Fue utilizado el método de maceración de las células con NaOH para visualizar la arquitectura del tejido conjuntivo. El dorso posterior de la lengua del oposum posee dos papilas valadas. Las secciones histológicas mostraron que la cubierta epitelial de estas papilas es del tipo escamoso, estratificado, queratinizado y asociadas con yemas gustativas y papilas pequeñas. Estas estructuras gustativas mostraron formas circulares u ovales. Imágenes al SEM mostraron la superficie de las células epiteliales con microcrestas, diferentes de los márgenes intercelulares y poros gustativos. El tejido conjuntivo denso está compuesto por unas redes de fibras colágenas y mostró papilas de diferentes formas. La arquitectura de lámina propia de las papilas valadas es de forma de un cono