Sandra Maria de Torres

Testicular development evaluation in rats exposed to 60 Hz and 1 mT electromagnetic field

Society has been increasingly exposed to low‐frequency electromagnetic fields (EMF), mainly from electricity distribution networks and electro‐electronic devices. Aiming to clarify the extension of possible interactions between EMF and testicular development, this study evaluated the effects of exposure to 60 Hz and 1 mT EMF in the maturation of testicular components. Wistar rats were exposed to EMF three times per day for 30 min, between the 13th day of gestation and the 21st postnatal day. Results showed a decrease in the following parameters: tubular diameter and seminiferous tubules area; seminiferous epithelium height; total volume of seminiferous tubule; tubular lumen; seminiferous epithelium; and Leydig cells. On the other hand, an increase was observed in connective tissue cells and blood vessels volume. Plasma testosterone, Sertoli cells population, tubular length and gonadosomatic index did not change when exposed to EMF. Histomorphometric analysis showed that exposure to EMF can promote a delay in testicular development. Copyright

Perinatal exposure to fluoxetine via placenta and lactation inhibits the testicular development in male rat offspring

Due to the widespread use of fluoxetine to treat depression, including pregnant and nursing women, the present study aimed to investigate the effects of in utero and lactational exposure to fluoxetine in rat offspring at post natal day 22. Wistar rat dams were orally treated with fluoxetine (5, 10, and 20 mg/kg) from day 13 gestation to day 21 lactation. Exposure to 10 and 20 mg/kg fluoxetine reduced the body and testis weights. The volume of the seminiferous tubules and epithelium were also reduced following 20 mg/kg fluoxetine exposure. The length of the seminiferous tubules and the population of Sertoli cells changed in offspring exposed to fluoxetine. The amount of seminiferous tubules lacking tubular lumen was higher in rats exposed to 20 mg/kg fluoxetine. Plasma testosterone showed no significant change. In conclusion, fluoxetine exposure via the placenta and lactation may inhibit and delay testicular development, adversely affecting several testicular parameters important for the establishment of sperm production in adulthood.

Testicular testosterone: Estradiol ratio in domestic cats and its relationship to spermatogenesis and epididymal sperm morphology

The phenomenon of teratozoospermia in felids is not fully understood. In this study, we investigated the testicular androgen:estrogen balance in domestic cats and correlated these data with epididymal sperm morphology and the degree of spermatogenic activity. During spring and summer, testes and blood samples were obtained from 37 mixed-breed domestic cats (12 to 48 mo). The epididymal sperm were harvested and evaluated for sperm counts, motility, and morphology. Distal cytoplasmic droplets were not considered a defect, and samples were considered normozoospermic if they contained more than 60% normal sperm (N = 25) or teratozoospermic if they contained less than 45% normal sperm (N = 12). The testicular and serum concentrations of testosterone (T) and 17β-estradiol (E2) were determined with an enzyme immunoassay. The gonadosomatic index and epididymal sperm numbers and motility did not differ between groups. The percentage of normal sperm was higher in normozoospermic (74.3 ± 2.0, mean ± SEM) than in teratozoospermic samples (43.1 ± 1.4). The most prevalent sperm defects in the teratozoospermic group were abnormal acrosomes (9.7 ± 2.0) and bent midpieces (12.2 ± 2.0) or tails (24.0 ± 2.7) with cytoplasmic droplets. Histomorphometric data were similar between groups, although there was a lower Leydig cell nuclear volume in teratozoospermic samples. Normozoospermic samples contained a higher percentage of haploid cells and had a higher index of total spermatogenic transformation than teratozoospermic samples. Serum concentrations of T (0.5 ± 0.1 vs. 0.8 ± 0.4 ng/mL) and E2 (9.5 ± 1.2 vs. 11.4 ± 2.3 pg/mL) and testicular T concentrations (471.6 ± 65.3 vs. 313.4 ± 57.6 ng/g) were similar between groups. However, compared with normozoospermic samples, teratozoospermic samples had higher testicular E2 concentrations (8.5 ± 3.6 vs. 5.4 ± 0.5 ng/g) and a lower T:E2 ratio (31.8 ± 4.1 vs. 87.2 ± 11.6). There were significant correlations between testicular E2 values and percentages of normal sperm (r = -0.55) as well as those with primary sperm defects (r = 0.58) or abnormal acrosomes (r = 0.64). The T:E2 ratio was also correlated with meiotic index (r = 0.45) and percentage of normal sperm (r = 0.58). In conclusion, a high testicular E2 concentration and a reduced T:E2 ratio were significantly associated with higher ratios of abnormal sperm types, suggesting that the balance between androgens and estrogens is an important endocrine component in the genesis of teratozoospermia in felids.

Fluoxetine induces changes in the testicle and testosterone in adult male rats exposed via placenta and lactation.

Abstract Fluoxetine is a selective serotonin reuptake inhibitor used to treat depression in pregnant and nursing women. However, recent studies have shown adverse effects in the male reproductive system after fluoxetine treatment. Aiming to analyze the extent of damage caused by fluoxetine in the testicle and safe doses for treatment during the perinatal period, the present study analyzed the effects of in utero exposure and exposure during lactation to fluoxetine in spermatogenesis of male rat offspring in adulthood. Wistar rat dams were orally treated with fluoxetine (5, 10, and 20 mg/kg) from 13 days of gestation to lactation day 21 and their offspring were analyzed at 90 days old. Results showed a reduction in the weight of testes (16%), epididymis (28%), and seminal glands (18%) in animals exposed to fluoxetine 20 mg/kg compared to the control. Seminal gland weight was also reduced 25% and 30% in animals exposed to 5 mg/kg and 10 mg/kg fluoxetine, respectively. Body weight of animals exposed to 20 mg/kg fluoxetine was reduced from post-natal day 9 to 36 compared to controls but from the post-natal day 9 to 36 there was no statistical difference. The volume of seminiferous epithelium reduced 17% and the total volume of Leydig cells reduced 30% in the group exposed to fluoxetine at 20 mg/kg. Furthermore, Leydig cells volume reduced 29% in the 5 mg/kg group. The length of the seminiferous tubules reduced 17% and daily sperm production per testicle also reduced 18% in animals exposed to the highest dose of fluoxetine compared to controls. The individual area of Leydig cells increased 7% and plasma testosterone increased 49% in animals exposed to fluoxetine at 20 mg/kg. In conclusion, exposure to 20 mg/kg fluoxetine via the placenta and during lactation may change testosterone and testicular parameters important for sperm production and male fertility in adulthood.

Endocrine and testicular changes induced by olanzapine in adult Wistar rats

Olanzapine is an atypical antipsychotic drug that has been increasingly used in acute treatment of, and therapeutic support for, schizophrenia, bipolar disorder and other psychoses. Considering that olanzapine acts on the dopaminergic receptor and this receptor is detected in germ cells, the present study aims to investigate the effects of treatment with different doses of olanzapine on spermatogenesis, plasma testosterone and weight of androgen‐dependent organs in rats. Results showed reduced plasma testosterone levels, and reduced testis, epididymis and prostate weights. Histopathologic and histomorphometric analysis of spermatogenesis indicated testicular degeneration. Furthermore, germ cell desquamation, syncytial multinucleated cells, Sertoli cell vacuolization and presence of necrotic and apoptotic germ cells wwew observed. Olanzapine treatment in rats promoted endocrinological changes and lesions in the testis, leading to a disturbance in spermatogenesis. Copyright

Cumulative mortality of Aedes aegypti larvae treated with compounds

OBJECTIVE To evaluate the larvicidal activity of Azadirachta indica, Melaleuca alternifolia, carapa guianensis essential oils and fermented extract of Carica papaya against Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae). METHODS The larvicide test was performed in triplicate with 300 larvae for each experimental group using the third larval stage, which were exposed for 24h. The groups were: positive control with industrial larvicide (BTI) in concentrations of 0.37 ppm (PC1) and 0.06 ppm (PC2); treated with compounds of essential oils and fermented extract, 50.0% concentration (G1); treated with compounds of essential oils and fermented extract, 25.0% concentration (G2); treated with compounds of essential oils and fermented extract, 12.5% concentration (G3); and negative control group using water (NC1) and using dimethyl (NC2). The larvae were monitored every 60 min using direct visualization. RESULTS No mortality occurred in experimental groups NC1 and NC2 in the 24h exposure period, whereas there was 100% mortality in the PC1 and PC2 groups compared to NC1 and NC2. Mortality rates of 65.0%, 50.0% and 78.0% were observed in the groups G1, G2 and G3 respectively, compared with NC1 and NC2. CONCLUSIONS The association between three essential oils from Azadirachta indica, Melaleuca alternifolia, Carapa guianensis and fermented extract of Carica papaya was efficient at all concentrations. Therefore, it can be used in Aedes aegypti Liverpool third larvae stage control programs.

Effects of intratesticular injection of zinc-based solution in rats in combination with anti-inflammatory and analgesic drugs during chemical sterilization

Aim: Chemical sterilization is a non-surgical method of contraception based on compounds injected into the testis to induce infertility. However, these injections can cause discomfort and pain able to impair the recovery of animals after this treatment. The objective of this study was to investigate if anti-inflammatories or pain relievers inhibited the sterilizing effect of zinc gluconate-based solution on the testis. Materials and Methods: Adult rats were treated in groups: G1 (control), G2 (dimethyl sulfoxide + dipyrone); G3 (dipyrone/zinc); G4 (dipyrone + celecoxib/zinc); G5 (dipyrone + meloxicam/zinc), and G6 (dipyrone + dexamethasone/zinc) in a single dose per day during 7 days. Animals were analyzed at 7, 15, and 30 days after treatments. Results: The zinc-induced a widespread testicular degeneration and decreased testosterone levels even in combination with anti-inflammatories or pain relievers. Testis, epididymis, prostate, and seminal vesicle had a weight reduction. The anti-inflammatory effect of dexamethasone interfered in the desired action of zinc gluconate in the 1st 15 days and celecoxib up to 7 days. Conclusion: Meloxicam plus dipyrone did not impair the chemical sterilization based on zinc gluconate, and it can be used to reduce nociceptive effects in animals after chemical sterilization.

Parasite load in intact and ulcerative skin of dogs with leishmaniais

The skin is the site of inoculation of Leishmania spp. in susceptible hosts, and consequently dermatopathies, especially ulcerative dermatitis, are the main clinical signs observed. The aim of this study was to assess parasitism of the skin (intact and ulcerated) among dogs that were naturally infected by Leishmania spp., through immunohistochemical analysis. Skin fragments (intact and ulcerated) were collected from 13 dogs with positive parasitological (bone marrow aspiration and exfoliative skin) and serological examinations (ELISA S7 Biogene) for Leishmania spp. These samples were processed using the immunohistochemical technique, involving the streptavidin-peroxidase complex. Ulcerative lesions were mainly observed on the elbows (53.84%; 7/13), nostrils (15.38%; 2/13), ears (23.07%; 3/13) and wings of the ilium (7.69%; 1/13). A severe parasite load was detected in 46.15% and 76.92% of the intact and ulcerated skin samples tested, respectively. The parasite load on ulcerated skin was statistically higher than on intact skin (p = 0.0221). These results indicate that the intact and ulcerated skin may host a high parasite load of amastigote forms of Leishmania spp., which can favor the transmission of the parasite.

Efeito do uso de pentoxifilina no período neonatal sobre a produção espermática em ratos Wistar adultos

Increasing doses of pentoxifylline were administrated to newborn Wistar rats in order to augment Sertoli cell number and sperm production in the adult rats. Thirty-seven neonate Wistar rats were distributed in four groups: control (n=10) and treated with 1mg/kg (n=10), 5mg/kg (n=9), and 10mg/kg (n=8) of pentoxifylline. At 90 days, the animals were submitted to anesthesia and intracardiac perfusion. Testes were colleted and routinely processed for inclusion in plastic resin with glycol methacrylate. Histological sections (4µm) were stained in toluidine blue/sodium borate (1%) and analyzed. Number of Sertoli cell per transversal section of seminiferous tubule had significant reduction in the groups treated with 5mg/kg and 10mg/kg of pentoxifylline as compared to control and the group that received 1mg/kg (P<0.05). The Sertoli cell index significantly increased in the group treated with 5mg/kg compared to control group. Pentoxifylline did not cause increase in the number of Sertoli cells and daily sperm production in adult male rats.