RESUMEN
Ethylene glycol monomethyl ether (EGME), which is widely used in various industrial products, is known for adverse effects on the reproductive system in adult rats. However, the effects of EGME on reproductive development in juvenile rats have not been demonstrated. In order to investigate the effects of EGME on the female reproductive system and pubertal development in juvenile rats, EGME was administered to female Sprague Dawley rats from postnatal day 21 to 41 at a dose level of 0, 50, 100, or 300 mg/kg. The animals were examined for general condition, body weight, vaginal opening (VO), estrous cyclicity, and histopathology of reproductive organs. EGME treatment resulted in a prolonged estrous cycle interval characterized by persistent diestrus at 50 mg/kg without effects on body weight, timing of VO, or histology of the reproductive organs. EGME at 100 mg/kg induced decreases in body weight gain, a delay of VO, and irregular estrous cycle with absence of corpora lutea and hypertrophy of uterine epithelium indicating disturbance of the ovulatory process associated with hormonal effect. At 300 mg/kg, there was significant delay of puberty due to severe growth retardation. The present results revealed that irregular estrous cycle is a first indicator of the effects of EGME on the female reproductive system in juvenile rats, with delayed pubertal onset and ovulatory process disturbance at a higher dose.
Asunto(s)
Glicoles de Etileno/efectos adversos , Glicoles de Etileno/toxicidad , Reproducción/efectos de los fármacos , Animales , Cuerpo Lúteo/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ciclo Estral/efectos de los fármacos , Glicoles de Etileno/administración & dosificación , Femenino , Ovulación/efectos de los fármacos , Embarazo , Pubertad/efectos de los fármacos , Ratas Sprague-Dawley , Aumento de Peso/efectos de los fármacosRESUMEN
Epimedii Herba is a traditional medicinal herb used in Korea and China and exerts estrogenic activity. In this study, we investigated the effect of peripubertal administration of Epimedii Herba on pubertal development in female rats using a modified protocol of the rodent 20-day pubertal female assay. Female Sprague-Dawley rats (21 days old after weaning, 10 rats per group) were divided into five groups: saline (Con), ethinyl estradiol (E2), Epimedii Herba ext (Ext), icariin (ICI), and icaritin (ICT), which were administered by oral gavage (E2 by subcutaneous injection) from postnatal day (PND) 21 through PND40. The time to vaginal opening (VO) was shorter for the Epimedii groups, particularly for the ICT group (p<0.05). Treatment with ICI and ICT significantly increased the duration of the estrus cycle (ICI, 2.78 days; ICT, 4.0 days; control, 1.78 days). Ovary weight was reduced by E2 treatment and increased by the Ext, ICI, and ICT treatments while the weight of the uterus and pituitary glands increased significantly only in the E2 and ICT groups. Although Epimedii Herba displayed relatively weak estrogenic activity, its repeated administration could affect pubertal development in female rats.