RESUMEN
To explore in mice if a 15% food restriction protocol during pregnancy programs the offspring postnatal development, with emphasis on reproductive function, and to assess if ghrelin (Ghrl) administration to mouse dams exerts effects that mimic those obtained under mild caloric restriction. Mice were 15% food-restricted, injected with 4 nmol/animal/day of Ghrl, or injected with the vehicle (control) thorough pregnancy. After birth, the pups did not receive further treatment. Pups born from food-restricted dams (FR pups) were lighter than Ghrl pups at birth, but reached normal weight at adulthood. Ghrl pups were heavier at birth and gained more weight than control pups (C pups). This effect was not associated with plasma IGF-1. FR pups showed a delay in pinna detachment and eye opening, while an advance was observed in Ghrl pups. FR pups showed also impairment in the surface-righting reflex. In both female FR and Ghrl pups, there was an advance in vaginal opening and, in adulthood, FR pups showed a significant decrease in their own litter size and plasma progesterone, and an increase in embryo loss. A delay in testicular descent was evident in male Ghrl pups. Changes in puberty onset were not associated with differences in the expression of Kiss1 in hypothalamic nuclei. Finally, in adulthood, FR pups showed a significant decrease in sperm quality. In conclusion, a mild food restriction thorough gestation exerted programming effects on the offspring, affecting also their reproductive function in adulthood. These effects were not similar to those of intragestational Ghrl administration.
Asunto(s)
Restricción Calórica/métodos , Desarrollo Fetal/fisiología , Ghrelina/administración & dosificación , Efectos Tardíos de la Exposición Prenatal/genética , Desarrollo Sexual/fisiología , Animales , Animales Recién Nacidos , Vías de Administración de Medicamentos , Femenino , Desarrollo Fetal/efectos de los fármacos , Masculino , Ratones , Embarazo , Efectos Tardíos de la Exposición Prenatal/inducido químicamente , Efectos Tardíos de la Exposición Prenatal/fisiopatología , Desarrollo Sexual/efectos de los fármacosRESUMEN
CONTEXT: Gender incongruence is defined as disharmony between assigned gender and gender identity. Several interventions are liable in this case including genital affirming surgery among other surgical interventions such as harmonization, and also the use of gonadotropin-releasing hormone agonists (GnRHa) for gonadal shielding. This aids in preventing the development of secondary sexual characteristics related to the genetic sex. OBJECTIVE: Systematically review the treatment of gender incongruity with GnRHa analogues. DATA SOURCES: The data source of this research is from Pubmed-Medline and Embase. STUDY SELECTION: Articles published between 2009 and 2019 which studied transgender adolescents treated with GnRHa were carefully selected. DATA EXTRACTION: Were extracted: design, sample size, study context, targeted subjects of intervention, outcome measures, and results. RESULTS: Eleven studies were included. The use of GnRHa seems to be well tolerated by the studied population. When started in pubertal transition, it was associated with a more distinct resemblance to body shape than to the affirmed sex. In addition to preventing the irreversible phenotypic changes that occur in cross-hormonal therapy, the use of GnRHa can equally contribute to the mental health of these adolescents. LIMITATION: There are few consistent studies on the use of GnRHa for gender incongruence. CONCLUSION: As the population of transgender children and adolescents grows, they acquire knowledge and greater access to the various forms and stages of treatment for sex reassignment. The medical community needs to be adequately prepared to better serve this population and offer the safest resources available.
Asunto(s)
Disforia de Género , Hormona Liberadora de Gonadotropina/agonistas , Pubertad , Adolescente , Disruptores Endocrinos/farmacología , Disforia de Género/metabolismo , Disforia de Género/fisiopatología , Disforia de Género/prevención & control , Humanos , Pubertad/efectos de los fármacos , Pubertad/fisiología , Desarrollo Sexual/efectos de los fármacos , Desarrollo Sexual/fisiología , Personas TransgéneroRESUMEN
CONTEXT: In 46,XY disorders of sexual development (DSD) patients, several factors may affect psychosexual development, leading to gender identity discrepancy and gender change later in life. Prenatal sexual steroid exposure and external genital virilization are considered to influence human psychosexual development, but their roles not completely understood yet. DESIGN: A total of 144 individuals (18 to 60 years of age) with a clinical/molecular diagnosis of 46,XY DSD from a single tertiary center were enrolled. Psychosexual outcomes (gender role, gender identity, and sexual orientation) were assessed using questionnaires and psychological test. The Sinnecker score was used for genital virilization measurement. Prenatal androgen exposure was estimated according to 46,XY DSD etiology. RESULTS: We found a positive association between prenatal androgen exposure and male psychosexual outcomes. Alternatively, prenatal estrogen exposure, age of gonadectomy, and the degree of external genital virilization did not influence any psychosexual outcome. There were 19% (n = 27) with gender change, which was associated with prenatal androgen exposure (P < 0.001) but not with the external genital virilization. The median age of gender change was 15 years, but most of the patients reported the desire for gender change earlier. CONCLUSIONS: Prenatal androgen exposure influenced psychosexual development in 46,XY DSD favoring male psychosexuality in all psychosexual outcomes, whereas the degree of external genital virilization did not influence these outcomes. The organizational effect of sexual steroids on psychosexuality at puberty appears to be weak in comparison with the prenatal effects. Prenatal androgen exposure also influenced female-to-male gender change frequency. All 46,XY DSD conditions with prenatal androgen exposure must be followed for gender issues in their management.
Asunto(s)
Andrógenos/administración & dosificación , Trastorno del Desarrollo Sexual 46,XY/psicología , Identidad de Género , Efectos Tardíos de la Exposición Prenatal/psicología , Procedimientos de Reasignación de Sexo/estadística & datos numéricos , Adolescente , Adulto , Trastorno del Desarrollo Sexual 46,XY/etiología , Trastorno del Desarrollo Sexual 46,XY/terapia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Embarazo , Estudios Retrospectivos , Conducta Sexual/efectos de los fármacos , Conducta Sexual/psicología , Desarrollo Sexual/efectos de los fármacos , Virilismo/psicología , Adulto JovenRESUMEN
The increase of obesity, bad eating habits and the lack of physical exercises are highly related to dyslipidemias. Rosuvastatin is a lipid-lowering drug and has been indicated to prevent cardiovascular diseases and to treat dyslipidemias due to its higher efficiency to reduce serum cholesterol concentrations. This study aimed to evaluate the reproductive adverse effects on sexual maturity due to rosuvastatin exposure in juvenile male rats during prepuberty. Three groups were randomly formed with newly weaned rats: control, whose rats received saline solution 0.9% and rosuvastatin at doses of 3 or 10 mg kg-1 day-1 , administered orally by gavage, from postnatal day 21 until preputial separation (average of 45 days for controls and 49 days for statin-treated animals), indicative of puberty onset. Male rats were maintained until sexual maturity and were killed on postnatal day 110. In the rosuvastatin-treated groups, the results showed diminished follicle-stimulating hormone, luteinizing hormone and testosterone concentrations, increased estradiol and prolactin concentrations, histopathologic alterations on testis and epididymis and decreased sperm quality. Moreover, statin-exposed groups showed decreased expression of androgen receptor on testis and epididymis and lower expression of aquaporin-9 on epididymal epithelium. In conclusion, administration of rosuvastatin to prepubertal male rats provoked long-term hormonal deregulation and impaired reproduction at adulthood.
Asunto(s)
Epidídimo/efectos de los fármacos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/toxicidad , Reproducción/efectos de los fármacos , Rosuvastatina Cálcica/toxicidad , Desarrollo Sexual/efectos de los fármacos , Espermatozoides/efectos de los fármacos , Testículo/efectos de los fármacos , Factores de Edad , Animales , Acuaporinas/metabolismo , Proliferación Celular/efectos de los fármacos , Epidídimo/metabolismo , Epidídimo/patología , Hormonas/sangre , Masculino , Tamaño de los Órganos/efectos de los fármacos , Ratas Wistar , Receptores Androgénicos/efectos de los fármacos , Receptores Androgénicos/metabolismo , Conducta Sexual Animal/efectos de los fármacos , Recuento de Espermatozoides , Motilidad Espermática/efectos de los fármacos , Espermatozoides/metabolismo , Espermatozoides/patología , Testículo/metabolismo , Testículo/patologíaAsunto(s)
Caimanes y Cocodrilos/crecimiento & desarrollo , Metiltestosterona/efectos adversos , Razón de Masculinidad , Desarrollo Sexual/efectos de los fármacos , Contaminantes Químicos del Agua/efectos adversos , Caimanes y Cocodrilos/anatomía & histología , Crianza de Animales Domésticos , Animales , Bovinos , Costa Rica , Femenino , Masculino , Ríos , Tilapia/crecimiento & desarrolloRESUMEN
Methylphenidate (MPH), a psychoactive agent that acts mainly by blocking the uptake of dopamine, is the main drug used to treat Attention Deficit Hyperactivity Disorder in children and adolescents. During development, important changes in brain architecture and plasticity occur, these changes, sensitive to exposure to stimulant drugs, are important in the control of GnRH secretion, influencing the release of sex hormones throughout the ovarian cycle. This study investigated the effects of repeated treatment with MPH during development on reproductive parameters of adult female rats. Wistar rats received MPH 2.5mg/kg, MPH 5.0mg/kg, or tap water (gavage) from postnatal day (PND) 21 to PND 60. From PND 75, one subgroup of females was selected for evaluation of estrous cycle, estradiol levels, weight of sexual organs, and histomorphological analysis of ovary follicles and uterus. In another subgroup, the sexual and maternal behaviors were evaluated at PND 90 and on lactational day 5, respectively. No significant alterations were observed in the MPH groups. This study demonstrated that repeated administration of MPH during the period corresponding to childhood to early adulthood does not interfere in the reproductive function of female rats in adulthood.
Asunto(s)
Envejecimiento/efectos de los fármacos , Estimulantes del Sistema Nervioso Central/farmacología , Metilfenidato/farmacología , Reproducción/efectos de los fármacos , Desarrollo Sexual/efectos de los fármacos , Análisis de Varianza , Animales , Animales Recién Nacidos , Peso Corporal/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Estradiol/sangre , Ciclo Estral/efectos de los fármacos , Femenino , Masculino , Conducta Materna/efectos de los fármacos , Ratas , Ratas Wistar , Conducta Sexual Animal/efectos de los fármacosRESUMEN
Fipronil, a phenylpyrazole insecticide, is used in agriculture, veterinary medicine, and public health. Because this insecticide is considered a potential endocrine disruptor, the aim of this study was to examine the influence of perinatal exposure to fipronil on neonatal female reproductive system development. Pregnant rats were exposed (via gavage) daily to fipronil (0.03, 0.3, or 3 mg/kg) from gestational day 15 to day 7 after birth, and effects on the reproductive functions assessed on postnatal day (PND) 22. No signs of maternal toxicity were observed during daily treatment with fipronil. Perinatal exposure to the highest dose of fipronil (3 mg/kg) delayed the age of vaginal opening (VO) and first estrus without markedly affecting the anogenital distance (AGD). Further, exposure to 0.3 mg/kg fipronil produced a significantly shorter estrus cycle and reduced number of cycles during the period of evaluation. However, the other reproductive parameters analyzed, including fertility, hormone levels, sexual behavior, and histology of ovaries and uterus, displayed no marked alterations. In this experimental model, fipronil interfered with development of neonatal female reproductive system as evidenced by delay in VO and estrus cycle alterations without apparent significant effects on fertility. Further studies are needed to identify the mechanisms of action associated with the observed female reproductive system changes.
Asunto(s)
Insecticidas/toxicidad , Resultado del Embarazo , Efectos Tardíos de la Exposición Prenatal/inducido químicamente , Efectos Tardíos de la Exposición Prenatal/patología , Pirazoles/toxicidad , Desarrollo Sexual/efectos de los fármacos , Animales , Estro/efectos de los fármacos , Femenino , Fertilidad/efectos de los fármacos , Hormonas Esteroides Gonadales/sangre , Lactancia , Masculino , Ovario/anatomía & histología , Ovario/efectos de los fármacos , Ovario/crecimiento & desarrollo , Embarazo , Ratas , Ratas Wistar , Conducta Sexual Animal/efectos de los fármacos , Útero/anatomía & histología , Útero/efectos de los fármacos , Útero/crecimiento & desarrollo , Vagina/crecimiento & desarrolloRESUMEN
Methylphenidate (MPH) is a psychostimulant drug which acts by blocking the dopamine and norepinephrine transporters and is the main drug used to treat attention deficit hyperactivity disorder in children and adolescents. During puberty, changes in neurotransmitter systems (including dopaminergic system) are engaged on the release of gonadal hormones and the development of cephalic structures responsible for reproductive function. This study investigated the effects of repeated treatment with methylphenidate during development on reproductive parameters of adult male rats. Wistar rats received MPH 2.5 mg/kg, MPH 5.0 mg/kg, or distilled water (gavage) from postnatal day (PND) 21 to PND 60. At PND 100, an increase in percentage of abnormal tail morphology sperm in MPH 2.5 and increase in testicular interstitial tissue volume in MPH groups as well as in the number of type A spermatogonia in MPH 5.0 group were observed. This study demonstrated that repeated administration of methylphenidate during periods corresponding childhood to early adulthood interfered on testicular function in rats at adult life.
Asunto(s)
Estimulantes del Sistema Nervioso Central/administración & dosificación , Genitales Masculinos/efectos de los fármacos , Metilfenidato/administración & dosificación , Reproducción/efectos de los fármacos , Desarrollo Sexual/efectos de los fármacos , Factores de Edad , Análisis de Varianza , Animales , Animales Recién Nacidos , Peso Corporal/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Epidídimo/efectos de los fármacos , Femenino , Masculino , Radioinmunoensayo , Ratas , Ratas Wistar , Recuento de Espermatozoides , Motilidad Espermática/efectos de los fármacos , Testículo/efectos de los fármacos , Testosterona/sangreRESUMEN
Environmental contaminants known as endocrine-disrupting chemicals (EDC) have been associated with adverse effects on reproductive processes. These chemicals may mimic or antagonize endogenous hormones, disrupting reproductive functions. Although preliminary studies focused on environmental estrogens, the presence of compounds with androgenic activity has also been described. This study examines exposure of female pregnant and lactating rats to low doses of androgens and assesses potential effects on female offspring. Pregnant Wistar rats were exposed to testosterone propionate (TP) at doses of 0.05, 0.1, or 0.2 mg/kg or corn oil (vehicle), subcutaneously, to determine influence on reproductive health of female offspring. There were two exposure groups: (1) rats treated from gestational day (GD) 12 until GD 20; and (2) animals treated from GD 12 until the end of lactation. Perinatal exposure to TP produced increased anogenital distance after birth and diminished height of uterine glandular epithelium at puberty in animals exposed to 0.2 mg/kg. However, these alterations were not sufficient to impair sexual differentiation and normal physiology of the female rat reproductive tract.
Asunto(s)
Andrógenos/toxicidad , Disruptores Endocrinos/toxicidad , Contaminantes Ambientales/toxicidad , Lactancia , Efectos Tardíos de la Exposición Prenatal , Desarrollo Sexual/efectos de los fármacos , Anomalías Urogenitales/inducido químicamente , Andrógenos/administración & dosificación , Animales , Relación Dosis-Respuesta a Droga , Disruptores Endocrinos/administración & dosificación , Endometrio/anomalías , Endometrio/efectos de los fármacos , Contaminantes Ambientales/administración & dosificación , Femenino , Desarrollo Fetal/efectos de los fármacos , Inyecciones Subcutáneas , Exposición Materna/efectos adversos , Embarazo , Distribución Aleatoria , Ratas , Ratas Wistar , Teratógenos/toxicidad , Propionato de Testosterona/administración & dosificación , Propionato de Testosterona/toxicidadRESUMEN
This study evaluated the reproductive effects of fluoxetine exposure in utero and during lactation on pregnancy outcomes and the sexual development of offspring. Pregnant Wistar rats were treated daily with fluoxetine (0.4, 1.7 and 17 mg/kg/day) or distilled water by gavage from gestation day (GD) 7 to lactation day (LD) 21. A significant reduction in maternal body weight was observed during pregnancy and lactation in dams exposed to 17 mg/kg fluoxetine. Hormone analysis revealed an increase in progestagen and glucocorticoid metabolites on GD 15 and oestrogen and progestagen metabolites on LD 7 in dams treated with 17 mg/kg fluoxetine. Oestrogen metabolites also were increased on LD 7 in dams treated with 0.4 mg/kg fluoxetine. Besides that, an increase in the weight of the adrenal glands and a reduction in uterine weight in dams exposed to highest dose of fluoxetine were observed. Finally, pup birthweight and the viability and weaning indices also were reduced in animals exposed to 17 mg/kg fluoxetine. Overall, maternal hormonal changes were only observed at the highest dose tested, which also induced maternal and foetal toxicity. No significant changes were seen in dams or offspring exposed to therapeutic-like doses.
Asunto(s)
Fluoxetina/administración & dosificación , Lactancia , Resultado del Embarazo/veterinaria , Desarrollo Sexual/efectos de los fármacos , Animales , Animales Recién Nacidos , Peso Corporal , Relación Dosis-Respuesta a Droga , Estrógenos/metabolismo , Femenino , Fluoxetina/efectos adversos , Masculino , Exposición Materna/efectos adversos , Embarazo , Progestinas/metabolismo , Ratas , Ratas Wistar , Reproducción/efectos de los fármacosRESUMEN
Based on the limited number of studies that have investigated the adverse effects of maternal treatment with antidepressants on the development of male descendents, this study was carried out in rat in order to evaluate if maternal exposure to fluoxetine (FLX) or St. John's Wort (SJW) could disrupt the development of male offspring. The dams were treated daily, by gavage, with 7.5 mg/kg of FLX or 100 mg/kg SJW during pregnancy and lactation. The reproductive and behavior parameters were analyzed in male pups. Results showed decreases in the weight of the full seminal vesicle and in the number of spermatozoa. Moreover, FLX-exposed pups presented reduced seminiferous epithelium height and diameter of seminiferous tubules. The present study shows that maternal exposure to FLX, but not SJW could interfere on reproductive parameters in adult male rats.
Asunto(s)
Antidepresivos/toxicidad , Fluoxetina/toxicidad , Hypericum/toxicidad , Testículo/efectos de los fármacos , Animales , Femenino , Masculino , Intercambio Materno-Fetal , Embarazo , Efectos Tardíos de la Exposición Prenatal , Ratas , Ratas Wistar , Conducta Sexual/efectos de los fármacos , Desarrollo Sexual/efectos de los fármacos , Espermatogénesis/efectos de los fármacos , Testículo/patología , Testosterona/sangreRESUMEN
OBJECTIVES: The objective of this study was to evaluate physical and sexual development and reproductive physiology in female rat offspring that developed in hyperglycemia conditions in utero and during lactation. MATERIALS AND METHODS: Maternal diabetes was induced in female rats by a single IV injection of streptozotocin before mating. Female offspring development was evaluated by means of the following parameters: physical development; age of vaginal opening and first estrus; weight and histological evaluation of uterus and ovaries; duration of the estrous cycle, sexual behavior, and fertility after natural mating. RESULTS: In the female offspring, maternal diabetes caused delays in initial physical development; diminution in ovary weight and number of follicles; and inferior reproductive performance compared with the control group. CONCLUSIONS: The exposure to hyperglycemia in uterus and during lactation caused delays in physical and sexual development, and affected the reproductive physiology of female rats negatively.
Asunto(s)
Diabetes Mellitus Experimental/inducido químicamente , Lactancia/efectos de los fármacos , Efectos Tardíos de la Exposición Prenatal/fisiopatología , Reproducción/efectos de los fármacos , Desarrollo Sexual/efectos de los fármacos , Animales , Animales Recién Nacidos/crecimiento & desarrollo , Modelos Animales de Enfermedad , Femenino , Fertilidad/efectos de los fármacos , Masculino , Ovario/efectos de los fármacos , Ovario/crecimiento & desarrollo , Embarazo , Distribución Aleatoria , Ratas , Conducta Sexual Animal/efectos de los fármacos , EstreptozocinaRESUMEN
OBJECTIVES: The objective of this study was to evaluate physical and sexual development and reproductive physiology in female rat offspring that developed in hyperglycemia conditions in utero and during lactation. MATERIALS AND METHODS: Maternal diabetes was induced in female rats by a single IV injection of streptozotocin before mating. Female offspring development was evaluated by means of the following parameters: physical development; age of vaginal opening and first estrus; weight and histological evaluation of uterus and ovaries; duration of the estrous cycle, sexual behavior, and fertility after natural mating. RESULTS: In the female offspring, maternal diabetes caused delays in initial physical development; diminution in ovary weight and number of follicles; and inferior reproductive performance compared with the control group. CONCLUSIONS: The exposure to hyperglycemia in uterus and during lactation caused delays in physical and sexual development, and affected the reproductive physiology of female rats negatively.
OBJETIVOS: O objetivo deste estudo foi avaliar o desenvolvimento físico e sexual e a fisiologia reprodutiva de ratas que se desenvolveram em condições hiperglicêmicas in utero e lactação. MATERIAIS E METODOS: Para induzir o diabetes nas ratas, foi utilizada estreptozotocina em dose única via intravenosa antes do acasalamento. A prole feminina foi avaliada por meio dos seguintes parâmetros: o desenvolvimento físico; a idade de abertura vaginal e do primeiro estro, peso e avaliação histológica do útero e ovários; a duração do ciclo estral, o comportamento sexual e a fertilidade após acasalamentos naturais. RESULTADOS: O diabetes materno provocou, na prole feminina, retardo no desenvolvimento físico; diminuição do peso dos ovários e do número de folículos; a performance reprodutiva foi inferior à do grupo controle. CONCLUSÕES: Concluiu-se que a exposição aos meios intrauterino e lactacional hiperglicêmicos provocou retardo no desenvolvimento físico e sexual e prejudicou a fisiologia reprodutiva de ratas.
Asunto(s)
Animales , Femenino , Masculino , Embarazo , Ratas , Diabetes Mellitus Experimental/inducido químicamente , Lactancia/efectos de los fármacos , Efectos Tardíos de la Exposición Prenatal/fisiopatología , Reproducción/efectos de los fármacos , Desarrollo Sexual/efectos de los fármacos , Animales Recién Nacidos/crecimiento & desarrollo , Modelos Animales de Enfermedad , Fertilidad/efectos de los fármacos , Ovario/efectos de los fármacos , Ovario/crecimiento & desarrollo , Distribución Aleatoria , Estreptozocina , Conducta Sexual Animal/efectos de los fármacosRESUMEN
BACKGROUND: A suboptimal intrauterine environment may have a detrimental effect on gonadal development and thereby increases the risk for reproductive disorders and infertility in adult life. Here, we used uncontrolled maternal diabetes as a model to provoke pre- and perinatal growth restriction and evaluate the sexual development of rat male offspring. METHODS: Maternal diabetes was induced in the dams through administration of a single i.v. dose of 40 mg/kg streptozotocin, 7 days before mating. Female rats presenting glycemic levels above 200 mg/dL after the induction were selected for the experiment. The male offspring was analyzed at different phases of sexual development, i.e., peripuberty, postpuberty and adulthood. RESULTS: Body weight and blood glucose levels of pups, on the third postnatal day, were lower in the offspring of diabetic dams compared to controls. Maternal diabetes also provoked delayed testicular descent and preputial separation. In the offspring of diabetic dams the weight of reproductive organs at 40, 60 and 90 days-old was lower, as well as sperm reserves and sperm transit time through the epididymis. However the plasma testosterone levels were not different among experimental groups. CONCLUSIONS: It is difficult to isolate the effects directly from diabetes and those from IUGR. Although the exposure to hyperglycemic environment during prenatal life and lactation delayed the onset of puberty in male rats, the IUGR, in the studied model, did not influenced the structural organization of the male gonads of the offspring at any point during sexual development. However the decrease in sperm reserves in epididymal cauda and the acceleration in sperm transit time in this portion of epididymis may lead to an impairment of sperm quality and fertility potential in these animals. Additional studies are needed in attempt to investigate the fertility of animals with intrauterine growth restriction by maternal diabetes and possible multigenerational effects.
Asunto(s)
Diabetes Mellitus Experimental/fisiopatología , Complicaciones del Embarazo/fisiopatología , Efectos Tardíos de la Exposición Prenatal/fisiopatología , Animales , Animales Recién Nacidos , Peso Corporal/efectos de los fármacos , Diabetes Mellitus Experimental/inducido químicamente , Epidídimo/efectos de los fármacos , Epidídimo/patología , Femenino , Lactancia , Masculino , Tamaño de los Órganos/efectos de los fármacos , Embarazo , Complicaciones del Embarazo/inducido químicamente , Ratas , Ratas Wistar , Reproducción/efectos de los fármacos , Desarrollo Sexual/efectos de los fármacos , Recuento de Espermatozoides , Espermatogénesis/efectos de los fármacos , Estreptozocina/toxicidad , Testículo/efectos de los fármacos , Testículo/patología , Testosterona/sangre , Factores de TiempoRESUMEN
We tested the effect of mono-ortho and di-ortho PCB congeners on northern leopard frog (Rana pipiens) hatching success, survival and sexual development. Embryos and tadpoles were exposed to two levels (0.5 and 50 microg/l) of two PCBs. PCBs 101 and 70 were selected because they were present in amphibians collected in the Fox River-Green Bay ecosystem and they have the theoretical structural requirements to be able to bind to the estrogen receptor and mediate estrogenic responses. The exposure of leopard frog embryos and tadpoles to PCB 70 and 101 did not significantly affect hatchability, survival, deformities or growth. There were significant departures from the expected 50:50 sex ratio in tadpoles/froglets exposed to PCB 101 and PCB 70. In all the cases of significant departure, the bias was towards higher number of females. Decrease in the proportion of male gonads and increase in the proportion of intersex gonads were observed with increasing PCB tissue concentrations. The effects of PCB congeners on sexual differentiation occur at concentrations higher than observed in frogs in the Fox River/Green Bay ecosystem.