The health effects of environmental chemicals on animals and humans are of growing concern. Human epidemiological and animal study data indicate that reproductive disorders and diseases begin early during prenatal and postnatal development. An increase of human male reproductive disturbance in the past several decades was associated to chemicals called endocrine disruptors (ED). Bisphenol A (BPA) is a ubiquitous organic environmental contaminant with ED activity. This study verified the effect of BPA exposure via breast milk during the lactation (early postnatal) period in male mice. Dams were exposed to oral BPA (300, 900, and 3000 µg/kg/BW/day) during the breastfeeding period (21 days). BPA at all concentrations significantly impaired sperm parameters in adult mice (8 months old), but mitochondrial functionality was more affected at BPA 3000. The acrosome membrane parameter was affected by BPA concentrations from 900 to 3000, and DNA integrity showed pronounced impairment at BPA 900 and 3000. BPA 3000 treatment also induced testicular degeneration and complete aplasia in some seminiferous tubules. Testicular oxidative damage was observed, and the total antioxidant capacity was impaired in BPA 900 and 3000 treatment groups. Taken together, the present study demonstrated long-term adverse effects of BPA in male mice, including reduced sperm quality, antioxidant capacity, and changes in testicular tissue. Our results clearly demonstrate the danger of BPA transferred via lactation on sperm quality registered even after a long time-elapsed from exposure to this harmful chemical.
South American Cyprinodontiform fishes are potential candidates to be used as model species in environmental toxicology. We sought for molecular and biochemical biomarkers of pollution in Poecilia vivipara (Poecilidae) and Jenynsia multidentata (Anablepidae). Partial nucleotide sequences for the cytochrome P450 1A (cyp1A), a classical biomarker of exposure to organic contaminants in fish, were identified in P. vivipara and J. multidentata (∼ 650 nucleotides) using degenerated primers and PCR. These sequences shared ∼ 90 % identity in the predicted amino acid sequence with the corresponding Cyp1A region of Fundulus heteroclitus. RT-qPCR analysis confirmed that cyp1A transcription was strongly induced in the liver and gills of J. multidentata (∼185-fold and ∼20-fold, respectively) and P. vivipara (122-fold and 739-fold, respectively), after 24-hrs exposure to 1 μM of the synthetic cyp1A inducer β-naphthoflavone (BNF). After 24 hs of injection with 1 μg.g-1 of the environmental carcinogenic contaminant benzo[a]pyrene (BaP), a decreased total antioxidant capacity against peroxyl radicals was observed both in liver of J. multidentata and gills of P. vivipara. BaP injection in both fishes did not cause changes in lipid peroxides (TBARS) levels, suggesting an absence of an oxidative stress situation caused by BaP injection in this study. The newly identified cyp1As would serve as general biomarkers of exposure to organic contaminant in future studies using P. vivipara and J. multidentata. The results also points out to the important species-specific differences in the biomarker responses in those South American cyprinodontiform fishes, which would suggests distinct resistance/susceptibility to polycyclic aromatic hydrocarbons.
A anestesia intravenosa é amplamente emprega em cães e a adição de adjuvantes complementa a analgesia e reduz doses de propofol empregadas. O objetivo deste estudo foi avaliar a associação da dexmedetomidina ao propofol na anestesia intravenosa em cães. Foram selecionadas 15 cadelas, adultas, hígidas, pesando 13,8 ±4,7 kg. Após pré-medicação com acepromazina e metadona, foram distribuídas nos grupos GDEX (n = 8) em que foi administrada dexmedetomidina (2 µg/kg em bolus + 1 µg/kg/h IV) ou controle GC (n = 7), com salina no mesmo volume, para então administrar propofol em ambos grupos. Os animais foram mantidos com propofol ajustando-se a taxa ao plano anestésico e suplementados com oxigênio à 100%. Foram avaliados: escala de indução, eletrocardiograma, frequências cardíaca e respiratória, pressão arterial sistólica com doppler, pressão de gás carbônico expirado e saturação de oxigênio periférico. Quando necessário foi administrado fentanil (2,5 µg/kg IV). Ao final, foram contabilizados a taxa de propofol, consumo de fentanil, tempo cirúrgico, extubação, alta anestésica e escore de sangramento. Houve redução média de 46% de na frequência cardíaca após administração de dexmedetomidina. Ao mesmo tempo que após indução a pressão arterial sistólica foi de 125 ±26 mmHg no GC comparada 148 ±42 mmHg em GDEX. Houve também, redução de 73% no consumo de fentanil e 29% na taxa de propofol. Ainda, o escore visual de sangramento foi maior no GDEX. Conclui- se que a associação da dexmedetomidina ao protocolo diminuiu a taxa de propofol e melhorou a analgesia transoperatória de cadelas submetidas à castração.
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