BACKGROUND: The industrial revolution has resulted in increased synthesis and the introduction of a variety of compounds into the environment and their potentially hazardous effects have been observed in the biota. The present study was aimed to evaluate the potential endocrine-disrupting effects of chronic exposure to the low concentrations of bisphenol S (BPS) in male rats. METHODS: Weaning male Sprague-Dawley rats (22 days old) were either exposed to water containing 0.1% ethanol for control or different concentrations of BPS (0.5, 5, and 50 μg/L) in drinking water for 48 weeks in the chronic exposure study. After completion of the experimental period, animals were dissected and different parameters (hormone concentrations, histology of testis and epididymis, oxidative stress and level of antioxidant enzymes in the testis, daily sperm production (DSP), and sperm parameters) were determined. RESULTS: Results of the present study showed a significant alteration in the gonadosomatic index (GSI) and relative reproductive organ weights. Oxidative stress in the testis was significantly elevated while sperm motility, daily sperm production, and the number of sperm in epididymis were reduced. Plasma testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) concentrations were reduced and estradiol levels were high in the 50 μg/L-exposed group. Histological observations involved a significant reduction in the epithelial height of the testis along with disrupted spermatogenesis, an empty lumen of the seminiferous tubules, and the caput region of the epididymis. CONCLUSION These results suggest that exposure to 5 and 50 μg/L of BPS for the chronic duration started from an early age can induce structural changes in testicular tissue architecture and endocrine alterations in the male reproductive system which may lead to infertility in males.
Animals ; Biomarkers ; Endocrine Disruptors/toxicity* ; Environmental Exposure/adverse effects* ; Environmental Pollutants/toxicity* ; Hypothalamo-Hypophyseal System/physiopathology* ; Infertility, Male/physiopathology* ; Male ; Phenols/toxicity* ; Rats ; Rats, Sprague-Dawley ; Sulfones/toxicity* ; Testis/physiopathology* ; Toxicity Tests, Chronic

The possible characteristics of spinal interaction between sildenafil (phosphodiesterase 5 inhibitor) and morphine on formalin-induced nociception in rats was examined. Then the role of the opioid receptor in the effect of sildenafil was further investigated. Catheters were inserted into the intrathecal space of male Sprague-Dawley rats. For induction of pain, 50 microliter of 5% formalin solution was applied to the hindpaw. Isobolographic analysis was used for the evaluation of drug interaction between sildenafil and morphine. Furthermore, naloxone was intrathecally given to verify the involvement of the opioid receptor in the antinociception of sildenafil. Both sildenafil and morphine produced an antinociceptive effect during phase 1 and phase 2 in the formalin test. The isobolographic analysis revealed an additive interaction after intrathecal delivery of the sildenafil-morphine mixture in both phases. Intrathecal naloxone reversed the antinociception of sildenafil in both phases. These results suggest that sildenafil, morphine, and the mixture of the two drugs are effective against acute pain and facilitated pain state at the spinal level. Thus, the spinal combination of sildenafil with morphine may be useful in the management of the same state. Furthermore, the opioid receptor is contributable to the antinocieptive mechanism of sildenafil at the spinal level.
Analgesics/*administration & dosage ; Analgesics, Opioid/*administration & dosage ; Animals ; Behavior, Animal/drug effects ; Dose-Response Relationship, Drug ; Drug Synergism ; Formaldehyde/toxicity ; Injections, Spinal ; Male ; Morphine/*administration & dosage ; Naloxone/administration & dosage ; Narcotic Antagonists/administration & dosage ; Pain/chemically induced/therapy ; Pain Measurement/drug effects ; Phosphodiesterase Inhibitors/*administration & dosage ; Piperazines/*administration & dosage ; Purines/administration & dosage ; Rats ; Rats, Sprague-Dawley ; Sulfones/*administration & dosage ; Time Factors