RESUMO
Environmental contamination by pharmaceuticals from industrial waste and anthropogenic activities poses adverse health effects on non-target organisms. We evaluated the neurobehavioral and biochemical responses accompanying exposure to ecological relevant concentrations of atenolol (0, 0.1, 1.0, and 10 µg/L) for seven uninterrupted days in adult zebrafish (Danio rerio). Atenolol-exposed fish exhibited anxiety-like behavior, characterized by significant bottom-dwelling with marked reduction in vertical exploration. Atenolol-exposed fish exhibited marked increase in the duration and frequency of aggressive events without altering their preference for conspecifics. Biochemical data using brain samples indicated that atenolol disrupted antioxidant enzyme activities and induced oxidative stress. Exposure to atenolol markedly decreased ATP and AMP hydrolysis without affecting ADP hydrolysis and acetylcholinesterase (AChE) activity. Atenolol significantly upregulated tryptophan hydroxylase 1 (tph1) mRNA expression but downregulated brain-derived neurotrophic factor (bdnf) mRNA. Collectively, waterborne atenolol elicits aggressive and anxiety-like responses in adult zebrafish, accompanied by oxidative stress, reduced nucleotide hydrolysis, altered tph1 and bdnf mRNA expression, which may impact the survival and health of fish in aquatic environment.
Assuntos
Atenolol , Comportamento Animal , Estresse Oxidativo , Poluentes Químicos da Água , Peixe-Zebra , Animais , Atenolol/farmacologia , Poluentes Químicos da Água/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Triptofano Hidroxilase/metabolismo , Triptofano Hidroxilase/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismoRESUMO
The aim of this study was to determine whether oxidative stress occurs in Escherichia coli-infected broiler breeder chicks, as well as the impact of this infection on bird growth. Twenty birds, 25-day-old female birds were divided into two groups (nâ¯=â¯10 per group): an intraperitoneally-infected group (1â¯mL containing 1.5â¯×â¯108â¯CFU of E. coli) and a control group that received 1â¯mL of culture medium (uninfected birds). Birds were weighed individually at the beginning and at the end of the experiment, and samples were collected on days 0, 5 and 10 post-infection (PI). No clinical signs were observed throughout the experimental period; nevertheless, on day 10 PI, there was lower growth and weight gain in infected birds than in the control group. The infected birds showed pericarditis and liver congestion, as well as moderate periportal inflammatory infiltrates with predominance of neutrophils. Significantly higher numbers of total leukocytes, lymphocytes, heterophils and monocytes were observed in the infected group on days 5 and 10 PI, as well as significantly higher total protein and globulin levels; albumin values significantly decreased over the same period. Levels of serum oxidative biomarkers (lipid peroxidation (TBARS) and free radicals (ROS)) were significantly higher at 10 PI, as was glutathione S-transferase (GST) activity during the same period. Hepatic ROS and protein thiol levels were significantly higher in E. coli-infected birds, as well as activities of the antioxidant enzymes catalase, superoxide dismutase. In the spleen, only GST activity was significantly higher for the infected group, unlike the brain, where SOD activity, ROS and non-protein thiol levels were significantly higher in infected birds than in the control group. These data suggested that colibacillosis causes oxidative stress in broiler breeder chicks, negatively affecting their weight gain.
Assuntos
Infecções por Escherichia coli/metabolismo , Estresse Oxidativo/fisiologia , Doenças das Aves Domésticas/metabolismo , Aumento de Peso/fisiologia , Animais , Antioxidantes/análise , Biomarcadores/sangue , Encéfalo/metabolismo , Encéfalo/patologia , Catalase/sangue , Galinhas , Escherichia coli , Infecções por Escherichia coli/sangue , Infecções por Escherichia coli/patologia , Feminino , Radicais Livres , Glutationa Transferase/sangue , Peroxidação de Lipídeos , Fígado/metabolismo , Fígado/patologia , Doenças das Aves Domésticas/sangue , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/patologia , Baço/metabolismo , Baço/patologia , Superóxido Dismutase , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismoRESUMO
A facile and efficient protocol for the highly selective direct sulfanylation of 3-bromocoumarins under DABCO promotion, was developed. The transformation took place with aromatic and aliphatic thiols as well as with α,ω-dithiols, affording the expected products in very good to excellent yields. Simple and convenient ways to access 4-((ω-mercaptoalkyl) thio)coumarins and the dimeric 4,4'-(alkane-1,4-diylbis(sulfanediyl))bis(coumarins) were also devised with the use of α,ω-alkanedithiols in different ratios with regards to the starting 3-bromocoumarin. The transformation seems to proceed through the DABCO-mediated thia-Michael stereoselective addition of the thiolate anion to the α,ß-unsaturated carbonyl system of the coumarin, followed by a DABCO-assisted stereoselective dehydrobromination of the resulting α-bromo carbonyl intermediate.