RESUMO
Heat can trigger testicular damage and impair fertility. Leydig cells produce testosterone in response to stimulation by luteinizing hormone (LH), which induces Ca2+ entry and K+ efflux through ion channels in their plasma membrane. Considering that mechanisms coordinating the Leydig cell responses to hyperthermic stress remain unclear; the present study analyzed the effects of heat stress (HS, 43°C, 15 min) and inhibition of Hsp90 on T-type calcium currents and voltage-dependent potassium currents (VKC) in mice Leydig cells. Results show that HS reduced the VKC steady state currents at +80 mV (45.3%) and maximum conductance (71.5%), as well as increased the activation time constant (31.7%) and the voltage for which half the channels are open (30%). Hsp90 inhibition did not change the VKC currents. T-type calcium currents were not affected by HS or Hsp90 inhibition. In conclusion, HS can slow the activation, reduce the currents and voltage dependence of the VKC, suggesting a possible role of these currents in the response to hyperthermic stress in Leydig cells.
Assuntos
Canais de Cálcio Tipo T/fisiologia , Proteínas de Choque Térmico HSP90/fisiologia , Resposta ao Choque Térmico/fisiologia , Células Intersticiais do Testículo/fisiologia , Canais de Potássio de Abertura Dependente da Tensão da Membrana/fisiologia , Animais , Benzoquinonas/farmacologia , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Temperatura Alta , Lactamas Macrocíclicas/farmacologia , Células Intersticiais do Testículo/efeitos dos fármacos , Masculino , CamundongosRESUMO
Shrimps can accumulate environmental toxicants and suffer behavioral changes. However, methods to quantitatively detect changes in the behavior of these shrimps are still needed. The present study aims to verify whether mathematical and fractal methods applied to video tracking can adequately describe changes in the locomotion behavior of shrimps exposed to low concentrations of toxic chemicals, such as 0.15µgL-1 deltamethrin pesticide or 10µgL-1 mercuric chloride. Results showed no change after 1min, 4, 24, and 48h of treatment. However, after 72 and 96h of treatment, both the linear methods describing the track length, mean speed, mean distance from the current to the previous track point, as well as the non-linear methods of fractal dimension (box counting or information entropy) and multifractal analysis were able to detect changes in the locomotion behavior of shrimps exposed to deltamethrin. Analysis of angular parameters of the track points vectors and lacunarity were not sensitive to those changes. None of the methods showed adverse effects to mercury exposure. These mathematical and fractal methods applicable to software represent low cost useful tools in the toxicological analyses of shrimps for quality of food, water and biomonitoring of ecosystems.
Assuntos
Fractais , Locomoção/efeitos dos fármacos , Mercúrio/toxicidade , Nitrilas/toxicidade , Penaeidae/efeitos dos fármacos , Praguicidas/toxicidade , Piretrinas/toxicidade , Gravação em Vídeo/métodos , Poluentes Químicos da Água/toxicidade , Animais , Comportamento Animal/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ecossistema , Penaeidae/fisiologia , Sensibilidade e Especificidade , SoftwareRESUMO
Male infertility is often related to reproductive age couples experiencing fertility-related issues. Men may have fertility problems associated with reversible testicular damage. Considering that men have been increasingly exposed to extremely low-frequency magnetic fields generated by the production, distribution and use of electricity, this study analyzed whether 60 Hz and 1 mT magnetic field exposure may impair spermatogenesis recovery after reversible testicular damage induced by heat shock using rats as an experimental model. Adult male rats were subjected to a single testicular heat shock (HS, 43 °C for 12 min) and then exposed to the magnetic field for 15, 30 and 60 d after HS. Magnetic field exposure during the spermatogenesis recovery induced changes in testis components volume, cell ultrastructure and histomorphometrical parameters. Control animals had a reestablished and active spermatogenesis at 60 d after heat shock, while animals exposed to magnetic field still showed extensive testicular degeneration. Magnetic field exposure did not change the plasma testosterone. In conclusion, extremely low-frequency magnetic field may be harmful to fertility recovery in males affected by reversible testicular damage.
Assuntos
Campos Eletromagnéticos/efeitos adversos , Temperatura Alta/efeitos adversos , Espermatogênese/efeitos da radiação , Testículo/fisiologia , Testículo/efeitos da radiação , Animais , Masculino , Ratos , Ratos Wistar , Testículo/citologia , Testículo/ultraestrutura , Testosterona/sangueRESUMO
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.
Assuntos
Antipsicóticos/toxicidade , Benzodiazepinas/toxicidade , Doenças dos Genitais Masculinos/induzido quimicamente , Espermatogênese/efeitos dos fármacos , Testículo/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Contagem de Células , Epididimo/efeitos dos fármacos , Epididimo/patologia , Doenças dos Genitais Masculinos/sangue , Doenças dos Genitais Masculinos/patologia , Letargia/induzido quimicamente , Masculino , Necrose/induzido quimicamente , Necrose/patologia , Olanzapina , Tamanho do Órgão/efeitos dos fármacos , Próstata/efeitos dos fármacos , Próstata/patologia , Ratos , Ratos Wistar , Células de Sertoli/efeitos dos fármacos , Células de Sertoli/patologia , Espermatócitos/efeitos dos fármacos , Espermatócitos/patologia , Testículo/patologia , Testosterona/sangueRESUMO
The antipsychotic drug, olanzapine, is prescribed for postpartum psychosis. Possible adverse effects on fertility of offspring are unclear. We investigated the effects of administering olanzapine via lactation on testicular development and endocrine function of prepuberal male rats. Olanzapine was administered to mothers at 2.5, 5 or 10 mg/kg. We found in male offspring increased body weight, decreased gonadosomatic index, testicular weight and epididymal weight. The volume of seminiferous tubules, seminiferous epithelium, Leydig cells, intertubule tissue and lymphatic space was reduced in rat pups exposed to olanzapine. Tubule diameter and length, seminiferous epithelium height, Leydig cell size and nuclear diameter also were reduced. Testosterone levels were reduced in the groups exposed to olanzapine, while prolactin levels were increased. We observed histopathology in testes of animals whose mothers had been treated with 2.5 mg/kg olanzapine; more severe pathology was observed in offspring whose mothers were administered higher doses. Administration of olanzapine to mothers during lactation produced testicular and endocrine pathology in prepuberal rats in a dose-dependent manner.
Assuntos
Lactação , Testículo , Ratos , Feminino , Animais , Masculino , Olanzapina/farmacologia , Testosterona , Atrofia/patologia , Tamanho do ÓrgãoRESUMO
Hyperprolactinemia is a pathological condition resulting from increased prolactin that directly affects reproduction, as this condition inhibits the release of LH, FSH and gonadal steroidogenesis, bringing several negative clinical associations in reproduction. In contrast, melatonin (MEL) plays an important role in the regulation of steroidogenesis and modulates damages to the process of spermatogenesis. The objective was to analyze the protective effects of exogenous melatonin on the testis of hyperprolactinemic adult rats. Forty-eight male rats were used, divided into two treatment periods: 30 and 60 days, each treatment was subdivided into three groups: Control, Hyper (hyperprolactinemia), and Hyper+MEL (hyperprolactinemia and melatonin). Treatment with melatonin was 200 µg/100 g, subcutaneously. Induction of hyperprolactinemia was obtained with a dose of 4 mg/kg of domperidone, subcutaneously. The results of the histopathology demonstrated that the animals in the Hyper group presented degeneration of germ cells when compared to the control. In addition, the degenerations were presented in smaller quantities in the Hyper+MEL, in both treatment periods, evidencing the benefits of the melatonin in gonadal regeneration. The Hyper group of both treatment periods showed a decrease in tubular diameter, epithelium height, and tubular area, in addition to a decrease in Sertoli cells, when compared to the control and the Hyper+MEL group. In conclusion, the hyperprolactinemia can affect the germinal epithelium and testicular microstructure; the exogenous melatonin has a protective effect against hyperprolactinemia, reducing testicular damage.
Assuntos
Hiperprolactinemia , Melatonina , Ratos , Masculino , Animais , Testículo , Melatonina/farmacologia , Hiperprolactinemia/induzido quimicamente , Hiperprolactinemia/patologia , Domperidona/farmacologia , ProlactinaRESUMO
The population exposure to electromagnetic fields (EMF) has been growing in recent decades. The generation, distribution and use of electric energy can generate low-frequency electromagnetic fields. The present study investigates the effects of EMF (60 Hz and 1 mT) on spermatogenesis of rats during different periods of maturation. Wistar rats were exposed to EMF from day 13 of gestation to postnatal day 21 or 90 in three daily applications of 30 min. Plasma testosterone concentration was not changed by EMF exposure; however, histopathological and histomorphometrical analyses of the testes showed testicular degeneration in a subset of animals exposed to EMF. The magnitude of the degenerative process varied between those individuals affected, indicating different individual sensitivity to EMF. The main alterations observed through transmission electron microscopy were highly electron-dense mitochondria with loss of their organization and cristae. Exposure to 60 Hz and 1 mT EMF can disturb spermatogenesis and may produce subfertility or infertility.
Assuntos
Campos Eletromagnéticos/efeitos adversos , Testículo/efeitos da radiação , Animais , Diagnóstico por Computador , Masculino , Microscopia Eletrônica , Ratos , Ratos Wistar , Testículo/patologia , Testículo/ultraestrutura , Testosterona/sangueRESUMO
Male infertility affects many couples around the world and can be related to environmental factors such as exposure to high temperatures. Even so, automated methods evaluating the seminiferous tubules to detect testicular damage are still scarce. In search of new approaches to automation in the microscopic analysis of the testis; the present study used the fractal dimension, lacunarity, multifractality and quantitative morphometry to quantify changes in microphotographs of the seminiferous lumen in testicles reversibly damaged by heat stress (43 °C, 12 min). The parameters fractal dimension, lacunarity, multifractality (Dq and α), perimeter, feret and circularity were able to detect changes in the seminiferous lumen at 7, 15 and 30 days after the testicular damage. These methods also detected the recovery of spermatogenesis at 60 days after heat stress. Area, f(α), centroid X and Y, roundness, rectangle height and width were unable to detect changes caused by heat stress. In conclusion, computer assisted methods applied to the seminiferous lumen images can be a useful new viewpoint to analyze microscopic changes in the testicles, a fast low-cost tool to assist in the automated quantification of testicular damage.
Assuntos
Fractais , Testículo , Resposta ao Choque Térmico , Humanos , Masculino , Túbulos Seminíferos , EspermatogêneseRESUMO
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.
Assuntos
Campos Eletromagnéticos/efeitos adversos , Desenvolvimento Fetal/efeitos dos fármacos , Efeitos Tardios da Exposição Pré-Natal/etiologia , Lesões Experimentais por Radiação/etiologia , Testículo/efeitos da radiação , Animais , Animais Recém-Nascidos , Feminino , Idade Gestacional , Masculino , Exposição Materna , Tamanho do Órgão/efeitos da radiação , Gravidez , Efeitos Tardios da Exposição Pré-Natal/patologia , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Lesões Experimentais por Radiação/patologia , Lesões Experimentais por Radiação/fisiopatologia , Ratos , Ratos Wistar , Túbulos Seminíferos/patologia , Túbulos Seminíferos/fisiopatologia , Túbulos Seminíferos/efeitos da radiação , Testículo/patologia , Testículo/fisiopatologia , Testosterona/sangueRESUMO
This study aims to report the diagnostic course and treatment of a fast-growing mycobacteria infection after cesarean delivery. We report the case of a 37-year-old woman admitted to the Infectious Diseases' Clinic of the Hospital das Clinicas da Universidade Federal de Pernambuco, Pernambuco State, Brazil, four months after a cesarean section, presenting with healing difficulties and located pain outside the surgical site. The first diagnosis was a probable rejection of the sutures that were not absorbed, but based on the clinical signs, reported history, complementary laboratory tests and no response to treatment with the conventional antibiotic therapy (cephalosporins/quinolones) prescribed, the ultimate diagnosis was a mycobacteriosis caused by Micobacterium fortuitum. Since fast-growing mycobacteria do not easily penetrate host tissues, they is mainly related to post-trauma or post-surgical procedures. It is extremely important to call attention to these occurrences in the gynecological-obsthetric field. Treatment for mycobacteriosis is often complicated because of the side effects of antibiotics, especially the ototoxicity of amikacin.
Assuntos
Infecções por Mycobacterium , Mycobacterium , Adulto , Antibacterianos/uso terapêutico , Brasil , Cesárea/efeitos adversos , Feminino , Humanos , GravidezRESUMO
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.
RESUMO
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.
Assuntos
Fluoxetina/farmacologia , Lactação , Exposição Materna , Placenta/metabolismo , Inibidores Seletivos de Recaptação de Serotonina/farmacologia , Testículo/efeitos dos fármacos , Testosterona/metabolismo , Animais , Feminino , Masculino , Gravidez , Ratos , Testículo/metabolismoRESUMO
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.
Assuntos
Fluoxetina/farmacologia , Testículo/efeitos dos fármacos , Animais , Peso Corporal/efeitos dos fármacos , Feminino , Lactação/efeitos dos fármacos , Masculino , Exposição Materna , Tamanho do Órgão/efeitos dos fármacos , Gravidez , Ratos , Túbulos Seminíferos/efeitos dos fármacos , Células de Sertoli/efeitos dos fármacos , Testículo/crescimento & desenvolvimento , Testosterona/sangueRESUMO
In current assay the serotoninergic system in newly-born Wistar rats underwent pharmacological modification by fluoxetine, a selective serotonin reuptake inhibitor (SSRI), to investigate its repercussion on testicular parameters in adult animals. Thirty animals were distributed according to treatment: control animals (n = 6), animals treated with 1 mg kg-1 (n = 6), 5 mg kg-1 (n = 6), 10 mg kg-1 (n = 6) and 20 mg kg-1 (n = 6) of fluoxetine (IP). When 150 days old, the animals were anesthetized and perfused intra-cardiacally with fixative solution. Testes were routinely processed for inclusion in plastic resin (methacrylate glycol). Further, 4 µm-thick histological sections were stained with toluidine blue/sodium borate 1% and analyzed histometrically. Pharmacological intervention on the serotoninergic system during the postnatal period of the testes development in Wistar rats with fluoxetine chlorohydrate reduced parameters, such as testicular weight, testis liquid weight and seminiferous tubules diameter. However, testicular parameters, such as daily sperm production (DSP), spermatogenesis efficiency (DSP/g/testis) and cell population in stage VII of adult animals, were not influenced by fluoxetine chlorohydrate usage during neonatal period. Results show that administration of fluoxetine during 21 days after birth may induce adverse changes in the spermatogenesis of adult rats.
No presente trabalho, o sistema serotoninérgico de ratos Wistar recém-nascidos foi farmacologicamente modificado por um inibidor seletivo de recaptação da serotonina, fluoxetina, com o objetivo de observar sua repercussão nos parâmetros testiculares em ratos adultos. Trinta animais foram distribuídos de acordo com o tratamento: controle (n = 6), tratado com 1 mg kg-1 (n = 6), 5 mg kg-1 (n = 6), 10 mg kg-1 (n = 6) e 20 mg kg-1 (n = 6) de fluoxetina. Aos 150 dias de vida, os animais foram anestesiados e perfundidos intracardiacamente com solução fixadora. Os testículos foram removidos e processados para inclusão em resina plástica (glicol metacrilato). Cortes histológicos com 4 µm de espessura foram corados por azul de toluidina/borato de sódio 1% e analisados histometricamente. O tratamento com fluoxetina reduziu nos parâmetros de peso testicular líquido e bruto, bem como no diâmetro dos túbulos seminíferos. Entretanto, os parâmetros testiculares de produção espermática diária (PED), eficiência espermática (PED/g/testículo) e população de células germinativas no estágio VII não estavam alteradas pelo tratamento com fluoxetina. Em conclusão, a administração de fluoxetina durante 21 dias após o nascimento pode induzir efeitos adversos na espermatogênese de ratos adultos.
Assuntos
Ratos , Fluoxetina , Células de Sertoli , EspermatogêneseRESUMO
A exposição da sociedade a Campos Eletromagnéticos (CEM) vem aumentando vertiginosamente em virtude da ampla expansão tecnológica observada nos últimos anos. Tanto a geração, como a distribuição e a utilização de energia elétrica podem gerar Campos Eletromagnéticos de baixa freqüência (50 e 60 Hz). Pesquisas vêm demonstrando que a exposição a estes CEM podem proporcionar alterações fisiológicas significativas, apesar disto, ainda não estão totalmente esclarecidos a extensão destes efeitos, nem os mecanismos de ação que envolve a interação dos CEM com os organismos biológicos. O presente trabalho teve como principal objetivo verificar os efeitos dos CEM (60 Hz e 1 mT) sobre a integridade de DNA e morfologia espermática de ratos sexualmente maduros, que foram expostos ao CEM durante diferentes períodos do seu desenvolvimento. Os resultados obtidos neste trabalho não encontraram indícios de alterações no DNA dos espermatozóides, porém, foram observadas alterações significativas na morfologia dos espermatozoides após a exposição ao CEM. Estas alterações na morfologia espermática podem reduzir o potencial reprodutivo. Portanto, devemos considerar o CEM como um potencial risco a saúde pública, recomendando- se a realização de mais pesquisas buscando estabelecer níveis seguros de exposição aos CEM.
The society's exposure to electromagnetic fields (EMF) has been growing considerable due to the great technological expansion observed in the last few years. Generation as well as distribution and use of electric energy can generate low frequency electromagnetic fields (50 and 60 Hz). Issues have been demonstrating that EMF exposure could provoke significantly physiological changes, however, the extension of EMF effects weren't totally clarified. The major objective of this issue was to evaluate the EMF (60 Hz and 1 mT) effects on DNA integrity and sperm morphology in Wistar rats with mature sexuality that were exposed during different stages of testicular development. According to our results, EMF did not change DNA integrity, but we could observe morphological changes in sperm after exposure to EMF. These changes in sperm morphology may reduce the reproductive potential. Therefore, we should consider the EMF as a potential risk to public health, recommending the implementation of further research seeking to establish safe levels of exposure to EMF.
Assuntos
Ratos , Patologia , Radiação não Ionizante , Espermatozoides , DNA , Radiação EletromagnéticaRESUMO
The Sertoli cell has fundamental importance to the development and maintenance of spermatogenesis, as well as it has a directly proportional numerical relationship to sperm production. The proliferative period of this cell in rats occurs between 13 days pre-natal and 21 days pos-natal, when is established the final population in adult animals. The Leydig cell can modulate the Sertoli cell proliferation during fetal and neonatal periodï throughï ï ï¢-endorphin. The manipulation of opioidergic system can promote changes in parameters related to development of nervous, endocrine and reproductive systems. By the way, the main purpose of this present work was to compare the effects of the blockade of opioid receptor blocking in Sertoli cells using naltrexone (50 mg kg-1) during fetal and neonatal period in Wistar rats. According to the results, the manipulation of opioidergic system during pre-natal period reduced the total length of seminiferous tubule and Sertoli cell population in adult rats, but sperm production was normal because this cell has had a compensatory response for spermatozoids support capacity.
As células de Sertoli têm fundamental importância para o desenvolvimento e manutenção da espermatogênese, bem como possuem uma relação numérica diretamente proporcional com a produção espermática. O período proliferativo destas células em ratos ocorre entre 13 dias pré-natal e 21 dias pós-natal, resultando na definição da população de células de Sertoli nos animais adultos. As células de Leydig podem modular a proliferação das células de Sertoli durante o período fetal e neonatal por meio da ï¢-endorfina. A manipulação do sistema opioidérgico durante esta fase pode promover alterações em parâmetros relacionados com o desenvolvimento dos sistemas nervoso, endócrino e reprodutivo. Em virtude disto, o objetivo do presente trabalho foi comparar os efeitos do bloqueio de receptores opioides nas células de Sertoli, utilizando o naltrexone (50 mg kg-1), durante o período proliferativo destas células em ratos Wistar. De acordo com nossos resultados, a manipulação do sistema opioidérgico durante o período pré-natal reduziu o comprimento total de túbulos seminíferos e a população de células de Sertoli em ratos adultos, porém, a produção espermática foi normal pela resposta compensatória desta célula na capacidade de suporte para espermatozoides.