Nandrolone decanoate and resistance exercise affect prostate morphology and hormone receptor interface in adult rats with implications for the aging process.

BACKGROUND: Nandrolone decanoate (ND) is an anabolic-androgenic steroid, and its indiscriminate use leads to subclinical alterations in the hypothalamic-pituitary-gonadal axis and androgen-dependent organs. OBJECTIVES: To evaluate the effects of ND, either alone or in combination with resistance exercise (RE), on the levels of sex hormones, converting enzymes, and steroid receptors and the morphology of the ventral prostate (VP) in adult and aged rats. METHODS: Forty Sprague-Dawley adult and aged rats were divided into four groups each, sedentary and trained with and without ND. The groups received treatments over 8 weeks. Adult animals were sacrificed immediately following treatment completion, while the aged groups were left untreated until 300 days of age. RESULTS: Adult and aged animals showed reductions in testosterone levels following the different treatments, and 17ß-estradiol levels were decreased in the ND-treated groups. The level of 5α-reductase type 2 (5αR2) and aromatase was increased significantly in the prostates of adult animals that performed RE. However, aromatase levels were decreased in the prostates of aged animals that performed RE and were treated with ND, while 5αR2 levels were reduced in aged animals that performed RE without ND treatment. When sex receptors levels were examined, the aged and trained animals presented low androgen receptor (AR) levels. Estrogen receptors (ERs) levels were increased in the prostates of adult animals that received ND. ERß levels were reduced after treatments in aged animals. The heights of the prostatic epithelium were reduced in all adult treated animals, coinciding with increases in PCNA and PAR4 levels. DISCUSSION: ND and RE alter the levels of hormone, converting enzymes, and sex steroid receptors and the morphology of the VP. These effects were observed in both adult and aged rats. CONCLUSION: ND, either with or without RE, during post-puberty stage is able to interfere with the morphophysiology of the prostate.

Nandrolone decanoate and resistance exercise training favor the occurrence of lesions and activate the inflammatory response in the ventral prostate.

Age is a key factor in the development of prostatic lesions. An increase in reactive oxygen species levels occurs during aging. Furthermore, the indiscriminate use of anabolic androgenic steroids and physical exercise alter the availability of hormones and may promote the appearance of lesions. This study examined whether the use of nandrolone decanoate (ND), associated or not with resistance exercise training, affects the pathways related to the inflammatory response in the ventral prostate of adult and aged rats. Sprague-Dawley rats were distributed into eight experimental groups: sedentary with ND, sedentary without ND, exercise with ND, and exercise without ND. The animals performed resistance exercise training and received ND two times/week (5 mg/kg, i.m.) for 8 weeks. Adult rats were killed immediately following treatment completion, and aged rats remained untreated until reaching 300 days of age. The adult animals that received ND and performed resistance exercise training showed a higher occurrence of lesions with TLR4 activation. Marked IL-6 expression occurred in the group that performed resistance exercise training. The group exposed to ND showed overexpression of TLR2, TLR4, NOX1, Nrf2, TNF-α, and P38MAPK. The animals that received ND and performed training showed increase levels of NFκB, IRF3, IL-6, TNF-α, and NOX1. TLR2 and TLR4 showed no upregulation in the aged animals. The groups exercise + ND showed lesions in the adult stage and after aging, followed by molecular alterations. We concluded that nandrolone decanoate and resistance exercise training can promote the onset of prostatic tumors in the adult stage, and during aging, activating pathways involved in the inflammatory response.

Morphological and morphometric study of the muscle fibers and neuromuscular junctions of the extensor digitorum longus in aged rats submitted to maternal protein restriction / Estudio morfológico y morfométrico de las fibras musculares y de las intersecciones neuromusculares del músculo extensor largo de los dedos de ratas de edad avanzada sometidas a la restricción proteica materna

Protein restriction implies the functional involvement of several systems and organs, including the skeletal muscle, because it is a protein reservoir in the body. This study sought to analyze the morphological and morphometric features of the muscle fibers and neuromuscular junctions (NMJs) of the extensor digitorum longus (EDL) muscle in rats at 365 days of age, submitted to maternal protein restriction during the gestation and lactation periods. Wistar rats were divided into two groups: a Control Group - mothers fed a normal-protein diet (17 % protein) during pregnancy and lactation; and a Restricted Group - mothers fed a low-protein diet (6 % protein) during pregnancy and lactation. The pups were kept with the mother throughout the lactation period (21 days), after which the offspring received a normal protein diet until 365 days of age. Histological (HE) and histoenzymological (NADH-TR) studies were conducted on the muscle fibers. The muscle was subjected to Nonspecific Esterase reaction to stain the Neuromuscular Junctions. Regarding the animals from the restricted group: the histologic analysis of the muscle fibers showed the presence of centralized nuclei and a diminished area; the histoenzymological study showed the different types of muscle fibers were randomly distributed in the EDL muscle and the area of the Type IIa muscle fiber was smaller; the ultrastructural study revealed disorganization of the Z line, and the presence of lipid droplets and vacuoles containing myelin figures in subsarcolemmal and intramiofibrilar regions; while the analysis of the NMJs exhibited no significant differences between the groups. Protein restriction in the pregnancy and lactation period may have affected the development of skeletal muscle, producing a permanent muscle-fiber deficit in the EDL muscle of the offspring.

La restricción proteica implica compromiso funcional de diversos sistemas y órganos, entre ellos, el músculo estriado esquelético, por ser una reserva de proteína del organismo. De esa forma, el presente trabajo procuró analizar las características morfológicas y morfométricas de las fibras musculares y de las intersecciones neuromusculares (JNMs) del músculo extensor largo de los dedos (EDL) en ratas de 365 días de edad, sometidas a restricción proteica materna durante los periodos de gestación y lactancia. Las ratas Wistar fueron separadas en dos grupos: El grupo Control - madres alimentadas durante la gestación y lactancia con ración normoproteica (17 % de proteína) y Grupo con restricción ­ madres alimentadas durante la gestación y lactancia con ración hipoproteica (6 % de proteína). Las crías permanecieron con la madre durante todo el periodo de lactancia (21 días) y después de este periodo la prole recibió ración normoproteica hasta los 365 días de edad. Se realizó un estudio histológico (HE) e histoenzimológico (NADH-TR) de las fibras musculares. Para la marcación de las JNMs, el músculo fue sometido a la reacción de Esterasa Inespecífica. El análisis histológico de las fibras musculares de los animales del Grupo con restricción mostró la presencia de núcleos centralizados y una disminución del área en el grupo con restricción. En el estudio histoenzimológico, el músculo EDL presentó una distribución aleatoria de los diferentes tipos de fibras musculares y el área de las fibras musculares del tipo IIa fue menor en el grupo con restricción. En relación al estudio ultraestructural, en los animales del grupo con restricción se observó desorganización de la línea Z, presencia de pequeñas gotas de lípidos y vacuolas que abrigaban figuras de mielina en las regiones subsarcolemal e intramiofibrilar. En el análisis de las JNMs no hubo diferencias significativas. La restricción proteica impuesta en el periodo de gestación y lactancia puede haber afectado el desarrollo del músculo esquelético, produciendo un déficit permanente en las fibras musculares del músculo EDL de la prole.

Sex differences in hepatic and intestinal contributions to nevirapine biotransformation in rats.

The understanding of the intestine contribution to drug biotransformation improved significantly in recent years. However, the sources of inter-individual variability in intestinal drug biotransformation, namely sex-differences, are still elusive. Nevirapine (NVP) is an orally taken anti-HIV drug associated with severe idiosyncratic reactions elicited by toxic metabolites, with women at increased risk. As such, NVP is a good model to assess sex-dimorphic metabolism. The aim of this study was to perform a comparative profiling of NVP biotransformation in rat intestine and liver and evaluate whether or not it is organ- and sex-dependent. Therefore, nevirapine-containing solutions were perfused through the intestine, in a specially designed chamber, or incubated with liver slices, from male and female Wistar rats. The levels of NVP and its Phase I metabolites were quantified by HPLC-UV. Liver incubation experiments yielded the metabolites 2-, 3-, 8-, and 12-OH-NVP, being 12-OH-NVP and 2-OH-NVP the major metabolites in males and females, respectively. Inter-sex differences in the metabolic profile were also detected in the intestine perfusion experiments. Herein, the metabolites 3- and 12-OH-NVP were only found in male rats, whereas 2-OH-NVP levels were higher in females, both in extraluminal (p<0.01) and intraluminal media. The metabolite 8-OH-NVP was not detected in the intraluminal media from either males or females. In this study, important inter-sex differences were detected in both organs, providing further clues to the sex-dimorphic profile of NVP toxicity. Moreover, an extra-hepatic contribution to NVP biotransformation was observed, strengthening the relevance of the intestinal contribution in the biotransformation of orally taken-drugs.

Efeito moluscicida do óleo essencial de Cymbopogon winterianus Jowitt (Poaceae) sobre Lymnaea columella (Say, 1817) e Biomphalaria tenagophila (D'Orbigny, 1835) / Molluscicidal effect of essential oil of Cymbopogon winterianus Jowitt (Poaceae) on Lymnaea columella (Say, 1817) and Biomphalaria tenagophila (D'Orbigny, 1835)

RESUMO O uso das substâncias moluscicidas convencionais no controle de planorbídeos vetores constitui-se uma importante ferramenta no combate da fasciolose hepática e esquistossomose. Sendo, portanto, de extrema relevância para a pecuária e para os serviços de Vigilância Epidemiológica. Por outro lado, a seleção de caramujos resistentes a tais substâncias e sua baixa seletividade estimulam a busca por novas substâncias. Neste sentido, o presente trabalho foi desenvolvido para avaliar o efeito do óleo essencial de Cymbopogon winterianusJowitt sobre Lymnaea columella e Biomphalaria tenagophila, hospedeiros intermediários de Fasciola hepatica e esquistossomose mansônica, respectivamente. O óleo essencial foi extraído a partir de folhas frescas utilizando o sistema Clevenger. A análise qualitativa foi realizada por meio de cromatografia gasosa acoplada a espectrometria de massas (CG/EM) e a quantificação dos constituintes presentes no óleo foi determinada por cromatografia gasosa acoplada ao detector de ionização de chama (CG/DIC). O efeito moluscicida foi avaliado utilizando seis moluscos de cada espécie e o óleo essencial de C. winterianus nas concentrações finais de 10, 20, 30, 40, 60, 80 e 100 ppm. A análise por cromatografia gasosa do óleo essencial possibilitou a identificação dos componentes majoritários geraniol (28,62%), citronelal (23,62%) e citronelol (17,10%). Os valores de DL100 e DL50para os moluscos das espécies L. columella e B. tenagophila foram, respectivamente, 60 e 40 ppm; 80 ppm e 60 ppm. O óleo de Cymbopogon winterianus demonstrou-se uma alternativa promissora para o controle dos moluscos, sendo a espécie L. columella mais sensível ao mesmo.

ABSTRACT Conventional molluscicides have been employed to control of planorbids vectors and are an important tool in order to control the hepatic fascioliasis and schistosomiasis. Thus, these substances have been showinggreat relevance for both Veterinary and Livestock Services as well as for Epidemiology and Disease Surveillance. On the other hand, the process of drug pressure for the selection of resistant snails to such components and their low selectivity have stimulated the search for new substances. Since researches on new drugs are the starting point to assist on themolluscs control, this work was developed in order to evaluate the effect of Cymbopogon winterianus Jowitt essential oil on L. columella and B. tenagophila, intermediate hosts of Fasciola hepatica and Schistosoma mansoni, respectively. The essential oil was obtained from fresh leaves by hydrodistillation using a Clevenger apparatus. A qualitative analysis was performed by gas chromatography together with a mass spectrometry one (GC/MS) and the chemical constituent content was determined by gas chromatography with a flame ionization detector (GC/FID). The molluscicidal effect was evaluated through the use of six snails of each species and C. winterianus essential oil at 10, 20, 30, 40, 60, 80 and 100 ppm. The result of the gas chromatographic analysis for the essential oil showed geraniol (28.62%), citronellal (23.62%) and citronellol (17.10%) as the major chemical components . The DL100 and DL50 values for L. columella and B. tenagophila species were, respectively, 60 and 40 ppm; 80 ppm and 60 ppm. L. columella had demonstrated more sensitivity to this essential oil than theB. tenagophila species. The C. winterianus essential oil proved to be a promising alternative for the control of these molluscs being the L. columella species the most sensitive of them.

Physical exercise on the rat ventral prostate: steroid hormone receptors, apoptosis and cell proliferation.

Studies have investigated the effect of exercise on prostate cancer risk. However, there are still doubts regarding the correlation between physical activity and the steroid hormones with respect to the reduction of the risk for prostatic lesions. We evaluated the levels of corticosterone, dihydrotestosterone (DHT), testosterone, estradiol, and steroid hormone receptors, and investigated the relationship between apoptosis and cell proliferation in the rat ventral prostate after training. Two groups were included in this study: control and trained. The trained group was submitted to training for 13 weeks (1 week of adaptation). Two days after the last training session, all animals were euthanized, and the intermediate and distal regions of the ventral prostate were collected and processed for immunohistochemistry, Western blotting and hormonal analyses. Physical exercise increased the corticosterone plasma, DHT and testosterone. In addition, androgen receptor expression was lower and estrogen receptor (ER) α and ER ß expression were higher in the trained group. However, the trained group showed disruption of the ratio of apoptotic to proliferating cells, indicating a predominance of apoptosis. We conclude that physical exercise alters the sex hormones and their receptors and is associated with the disruption of the balance between apoptosis and cell proliferation in the rat ventral prostate.

Long-term melatonin treatment reduces ovarian mass and enhances tissue antioxidant defenses during ovulation in the rat

Melatonin regulates the reproductive cycle, energy metabolism and may also act as a potential antioxidant indoleamine. The present study was undertaken to investigate whether long-term melatonin treatment can induce reproductive alterations and if it can protect ovarian tissue against lipid peroxidation during ovulation. Twenty-four adult female Wistar rats, 60 days old (± 250-260 g), were randomly divided into two equal groups. The control group received 0.3 mL 0.9 percent NaCl + 0.04 mL 95 percent ethanol as vehicle, and the melatonin-treated group received vehicle + melatonin (100 µg·100 g body weight-1·day-1) both intraperitoneally daily for 60 days. All animals were killed by decapitation during the morning estrus at 4:00 am. Body weight gain and body mass index were reduced by melatonin after 10 days of treatment (P < 0.05). Also, a marked loss of appetite was observed with a fall in food intake, energy intake (melatonin 51.41 ± 1.28 vs control 57.35 ± 1.34 kcal/day) and glucose levels (melatonin 80.3 ± 4.49 vs control 103.5 ± 5.47 mg/dL) towards the end of treatment. Melatonin itself and changes in energy balance promoted reductions in ovarian mass (20.2 percent) and estrous cycle remained extensive (26.7 percent), arresting at diestrus. Regarding the oxidative profile, lipid hydroperoxide levels decreased after melatonin treatment (6.9 percent) and total antioxidant substances were enhanced within the ovaries (23.9 percent). Additionally, melatonin increased superoxide dismutase (21.3 percent), catalase (23.6 percent) and glutathione-reductase (14.8 percent) activities and the reducing power (10.2 percent GSH/GSSG ratio). We suggest that melatonin alters ovarian mass and estrous cyclicity and protects the ovaries by increasing superoxide dismutase, catalase and glutathione-reductase activities.

IGFR-I expression and structural analysis of the hard palatine mucosa in an ethanol-drinking rat strain (UChA and UChB).

The study analyzed the effects of chronic alcohol ingestion on the ultrastructure of the lining epithelium of the hard palatine mucosa of rats UChA and UChB (lines with voluntary alcohol consumption) in order to contribute to the understanding of the consequences of alcohol abuse for the morphology of the digestive system. Thirty female adult animals aged 120 days were divided into three experimental groups. (1) Ten UChA rats (genetically low ethanol consumer) with voluntary intake of 10% v/v (5.45 g/kg/day) ethanol solution and water. (2) Ten UChB (genetically high ethanol consumer) rats with voluntary intake of 10% v/v (7.16 g/kg/day) ethanol solution and water. (3) Ten Wistar rats with voluntary ad libitum water intake (control group). Both groups received Nuvital pellets ad libitum. The IGFR-I expression was intense in both experimental groups. The epithelial cells of the alcoholic rats UChA and UChB showed many alterations such as the presence of lipid droplets, altered nuclei, nuclei in corneum layer and disrupted mitochondria. It was concluded that ethanol intake induces ultrastructural lesions in the hard palatine mucosa.

Long-term melatonin treatment reduces ovarian mass and enhances tissue antioxidant defenses during ovulation in the rat.

Melatonin regulates the reproductive cycle, energy metabolism and may also act as a potential antioxidant indoleamine. The present study was undertaken to investigate whether long-term melatonin treatment can induce reproductive alterations and if it can protect ovarian tissue against lipid peroxidation during ovulation. Twenty-four adult female Wistar rats, 60 days old (± 250-260 g), were randomly divided into two equal groups. The control group received 0.3 mL 0.9% NaCl + 0.04 mL 95% ethanol as vehicle, and the melatonin-treated group received vehicle + melatonin (100 µg·100 g body weight(-1)·day(-1)) both intraperitoneally daily for 60 days. All animals were killed by decapitation during the morning estrus at 4:00 am. Body weight gain and body mass index were reduced by melatonin after 10 days of treatment (P < 0.05). Also, a marked loss of appetite was observed with a fall in food intake, energy intake (melatonin 51.41 ± 1.28 vs control 57.35 ± 1.34 kcal/day) and glucose levels (melatonin 80.3 ± 4.49 vs control 103.5 ± 5.47 mg/dL) towards the end of treatment. Melatonin itself and changes in energy balance promoted reductions in ovarian mass (20.2%) and estrous cycle remained extensive (26.7%), arresting at diestrus. Regarding the oxidative profile, lipid hydroperoxide levels decreased after melatonin treatment (6.9%) and total antioxidant substances were enhanced within the ovaries (23.9%). Additionally, melatonin increased superoxide dismutase (21.3%), catalase (23.6%) and glutathione-reductase (14.8%) activities and the reducing power (10.2% GSH/GSSG ratio). We suggest that melatonin alters ovarian mass and estrous cyclicity and protects the ovaries by increasing superoxide dismutase, catalase and glutathione-reductase activities.

Structural evaluation of the effects of chronic ethanol ingestion on the testis of Calomys callosus.

Chronic exposure to ethanol may results in pathophysiologic changes in cellular function. The present work was designed to investigate the morphology of testis submitted to experimental ethanol ingestion. Experimental animals were divided into two groups. The control group (n=23) received a solid diet and tap water and the alcoholic group (n=23) received the same solid diet and ethanol P.A. diluted 20% in water (v/v). After 120 days of treatment, all animals were anesthetized, weighed and sacrificed. Testosterone and luteinizing hormone levels in serum were lower in the alcoholic group than in the control group. Histological and ultrastructural alterations were observed in the testicular alcoholic germinative cells like enormous spaces, lipid droplets accumulation, digestive vacuoles, irregular diameter of the seminiferous tubules and interstitial dilated blood vessels. It was concluded that 20% ethanol provokes lesions on the testis germinative epithelium probably inducing gonadal dysfunction.

Evaluation of the ethanol intake on the Calomys callosus seminal vesicle structure.

The effects of chronic alcohol ingestion on the structure of the glandular epithelium of the seminal vesicle of the rodent Calomys callosus were analyzed in 24 adult animals aged 3 months divided into three experimental groups. The control group received a solid diet and tap water, the alcoholic group received the same solid diet and ethanol P.A. diluted 20% in water (v/v) for 4 months. The abstinent group received the same liquid diet of the alcoholic one for the same period and after that the alcoholic diet was changed by water for a period of 3 months. After treatment, all animals were anesthetized, weighed and sacrificed. At the end of treatment, mean body weight did not differ between animal groups. The glandular epithelial cells of the alcoholic and abstinent groups showed atrophy and ultrastructural alterations such as the presence of altered nuclei, intense dilatation of the cisterns of the granular endoplasmic reticulum, intense digestive vacuoles and lipid droplets. Ethanol ingestion provokes marked lesions on the epithelium of the seminal vesicle probably interfering on the glandular secretion.

Morphologic changes in the urethral epithelium in an ethanol-drinking rat strain (UChA and UChB).

The extreme use of ethanol causes metabolic and pathologic changes in testes and urogenital system in different animal species. The enzyme alcohol dehydrogenase (ADH) catalyses the conversion of ethanol into carcinogenic metabolite acetaldehyde which is partly excreted into the urine. However, papers relating the chronic ethanol consumption to the urethral morphology are unknown. This work evaluates the toxic effect of the chronic ethanol ingestion on the urethral epithelium of UChA and UChB rats. Conventional techniques of histology, histochemistry, immunohistochemistry and ultrastructural analysis were used. The analysis showed the presence of lipid drops and intercellular spaces in the epithelial cells in the urethra of UChA and UChB rats compared to control rats. Urethral neuroendocrine cell were observed and characterized for presenting vesicles containing electron-dense granules associated with nervous fibers. We conclude that the chronic consumption of ethanol induces the presence lipid drops in the epithelial cells of the urethra of UChA and UChB rats. The NE cells of the urethra of UChA and UChB rats did not show alterations under chronic effect of the ethanol.

Morphological alterations on the prostate of Calomys callosus submitted to chronic ethanol ingestion.

The objective of the present study was to assess the possible toxic effects of chronic alcohol ingestion on the ultrastructure of the glandular epithelium of the prostate of the rodent Calomys callosus, in order to contribute to the understanding of the consequences of alcohol abuse for the morphology of the male reproductive apparatus. Sixteen adult animals aged three months were divided into two experimental groups. The control group received a solid diet and tap water, and the alcoholic group received the same solid diet and ethanol P.A. diluted 20% in water (v/v). After 120 days of treatment, all animals were anesthetized, weighed and sacrificed. At the end of treatment, mean body weight did not differ between control and alcoholic animals. The prostate epithelial cells of the alcoholic group showed intense atrophy and ultrastructural alterations such as the presence of lipid droplets, altered nuclei, ruptured mitochondrial cristae, and intense dilatation of the cisterns of the granular endoplasmic reticulum. It was concluded that 20% ethanol provokes marked lesions on the epithelium of the prostate probably interfering on the glandular secretion.

Ultrastructural changes on the hard palatine mucosa of Calomys callosus after 120 days of experimental chronic alcoholism.

The present study analyzed the toxic effects of chronic alcohol ingestion on the ultrastructure of the lining epithelium of the hard palatine mucosa of the rodent Calomys callosus, in order to contribute to the understanding of the consequences of alcohol abuse for the morphology of the digestive system. Twenty-six adult animals aged three months were divided into two experimental groups. The control group received a solid diet and tap water, and the alcoholic group received the same solid diet and ethanol P.A. diluted 20% in water (v/v). After 120 days of treatment, all animals were anaesthetised, weighed and sacrificed. At the end of treatment, mean body weight did not differ between control and alcoholic animals. The epithelial cells of the alcoholic group showed many alterations such as the presence of lipid droplets, nuclei in corneum layer, nuclei with increase peripheral chromatin and greater electron density, altered mitochondria, and intense dilatation of the intercellular spaces. It was concluded that 20% ethanol provokes marked ultrastructural lesions in the hard palatine mucosa.

Morphology of the vas deferens in an ethanol-drinking strain of rats (UChA and UChB).

Chronic alcoholism alters reproduction and therefore may be responsible for alterations of vas deferens, which are the subject of this analysis in UCh ethanol-drinking rats. The proximal and distal segments of the vas deferens of 20 animals were submitted to macroscopic, light microscopy, electron microscopy and morphometric analysis. The UCh rats showed atrophy of the epithelium of the vas deferens and alterations of the hypothalamus-pituitary axis. Ethanol induces changes in the epithelium of the vas deferens and hypothalamus-pituitary axis of UCh rats.

Ultrastructure of the urethra of the Mongolian gerbil.

OBJECTIVE: The urethra is the main port of entry of sexually transmitted pathogens. However, papers on the morphology of the urethra are scarce. The Mongolian gerbil is a rodent native of the Mongolia and China and has been utilized as a laboratory animal since the 1960s. This work describes the ultrastructure of the urethra of the Mongolian gerbil to provide data for future experimental studies. METHODS: The urethra of ten adult male gerbils was studied by transmission electron microscopy. RESULTS: The epithelium of the pelvic urethra possesses two cell types: I and II, without the formation of cellular layers, while the penile urethra possesses cellular layers: basal, intermediate and superficial. The urethra presents neurosecretory cells belonging to the amine precursor uptake and decarboxylation system. CONCLUSIONS: The urethral epithelium of the gerbil is a neurosecretory epithelium, part of the amine precursor uptake and decarboxylation system.

Structure of the pelvic and penile urethra--relationship with the ducts of the sex accessory glands of the Mongolian gerbil (Meriones unguiculatus).

The urethra is the main place of entry for sexually transmitted pathogens. However, there is little literature on the morphology of the urogenital system, principally the urethra and ducts of the sex accessory glands. The Mongolian gerbil is an insectivorous, herbivorous and monogamous rodent with nocturnal habits; it has been used successfully as a laboratory animal since the 1960s. Therefore, the objective of the present paper was to describe the structure and ultrastructure of the urethra and its relations to the ducts of the accessory sex glands of the Mongolian gerbil (Meriones unguiculatus), contributing to the understanding of the reproductive biology of the rodent and aiming to provide data for future experimental studies. Conventional techniques of light and scanning electron microscopy were utilized. The urethra and ducts of the accessory sex glands are similar to those of the albino rat and the mouse. However, there is variation in drainage type among accessory sex glands for the inner urethra. The ducts of the seminal vesicle, the ductus deferens, drain their contents independently into the ampullary duct that opens in the urethra. The ducts of the prostate, coagulating and bulbourethral glands drain their contents independently into the urethra.

Morphological effects on the hard palatine mucosa of Calomys callosus submitted to experimental chronic alcoholism.

The morphological effects of ethanol ingestion on the hard palatine mucosa of adult male Calomys callosus were observed. Twenty rodents were divided into two experimental groups: the control group received solid diet, Purina rat chow, and tap water ad libitum; the alcoholic group received the same solid diet and ethanol P.A. diluted 20% in water (v/v). After 270 days of treatment, all animals were sacrificed and the hard palatine mucosa were prepared for TEM and SEM methods. The epithelial cells of the alcoholic group showed some alterations like cytoplasmatic lipid droplets, pycnotic nucleus and increased mitochondrial size. The lamina propria also presented intense lipid droplets accumulation. The morphological changes suggested that chronic ethanol consumption was able to modify the integrity of the mucosa.

Kinetics of spermatogenesis in the Mongolian gerbil (Meriones unguiculatus).

The Mongolian gerbil (Meriones unguiculatus) is a small rodent native to the arid regions of Mongolia and Northeastern China. The present study provides descriptions of both the cellular associations of the seminiferous-epithelium cycle and relative frequencies of stages in the gerbil. Based on the development of the acrosomic system and the nuclear morphology changes using the PAS-H staining technique, the transformation of spermatids into spermatozoa was divided into 15 steps. The first 12 steps were used to identify 12 stages or cellular associations and the other three steps were spread among the first six stages of the cycle of the seminiferous epithelium. The relative frequencies found for stages I through XII were: 13.15; 8.06; 8.98; 6.48; 5.37; 6.71; 7.36; 7.45; 7.27; 5.83; 11.53 and 11.81, respectively. Stage I had the highest frequency while stage V proved the lowest frequency among the XII stages. The pattern of spermatogenesis is similar to those of rodents used as laboratory animals. The present description is the first for this rodent and provides the foundation for a variety of future studies of the testis in this animal.

Ultrastructural study of acrosome formation in mongolian gerbil (Meriones unguiculatus).

Spermatogenesis is a complex and very well organized process lasting from 30 to 75 days in mammals. The spermatogenic process has been described mainly in laboratory mammals, such as the rat, while correspondent studies in wild animals are scarce. The gerbil (Meriones unguiculatus) is a small rodent native of the arid regions of Mongolia and China. Few reports are available on reproduction in the male Mongolian gerbil. The present study provides the first description of the ultrastructural alterations in spermatid cytoplasm and nucleus, with particular reference to acrosome formation in gerbils. The testes were processed by conventional transmission electron microscopy technique. Based on the development of the acrosomal system and changes in nuclear morphology, the transformation of spermatids in spermatozoon was divided into 15 steps. There were four phases in the spermiogenesis process in the gerbil: Golgi, cap, acrosomal and maturation phases. This provides the foundation for a variety of future studies of the spermiogenesis of this animal.