RESUMO
AIM: Although progesterone (P4) has a beneficial effect on the cardiovascular system, P4 actions on the coronary bed have not yet been fully elucidated. This study evaluated the effect of progesterone treatment on endothelium-dependent coronary vascular reactivity in Wistar rats. MAIN METHODS: Eight-week-old adult rats were divided into Sham, Ovariectomized (OVX), Ovariectomized and progesterone treated (OVX P4). The OVX P4 group received daily doses of progesterone (2 mg/kg/day). Vascular reactivity was assessed by a modified Langendorff technique. The intensity of eNOS, Akt, and gp91phox protein expression was quantified by Western blotting. Superoxide anion (O2â-) and hydrogen peroxide (H2O2) production was measured by dihydroethidium and 2',7'-dichlorofluorescein, respectively. KEY FINDINGS: Treatment with P4 was able to prevent the reduction in baseline coronary perfusion pressure induced by ovariectomy. We observed that endothelium-dependent coronary vasodilation was reduced in the OVX group and potentiated in the OVX P4 group. Following the inhibition of the nitric oxide (NO) pathway, the bradykinin-induced relaxing response was potentiated in the OVX P4 group. With regard to the combined inhibition of NO and prostanoids pathways, the OVX P4 group showed a greater relaxing response, similar to what was found upon individual inhibition of NO. After the combined inhibition of NO, prostanoids and epoxyeicosatrienoic acids' pathways, the vasodilatory response induced by BK was abolished in all groups. SIGNIFICANCE: Treatment with P4 prevented oxidative stress induced by ovariectomy. These results suggest that progesterone has a beneficial action on the coronary vascular bed.
Assuntos
Vasos Coronários/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Progesterona/farmacologia , Vasodilatação/efeitos dos fármacos , Animais , Feminino , Peróxido de Hidrogênio/metabolismo , NADPH Oxidase 2/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Ovariectomia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Transdução de Sinais/efeitos dos fármacos , Superóxidos/metabolismoRESUMO
Acetaminophen (APAP) is one of the most widely consumed drugs in the world. Studies have shown renal and hepatic damage as the direct result of high oxidative stress induced by APAP. Since the cardiovascular system is sensitive to oxidative stress and literature describes increased cardiovascular dysfunction in APAP consumers, this work aimed to evaluate harmful effects of APAP on the vascular system. Rats were exposed to APAP (400 mg/kg/day in drinking water) for 14 days. Plasma and aortas were collected and stored in - 80 °C and a selection of arteries was prepared for isometric tension recordings, morphological, immunohistochemical and protein expression analysis. The APAP-treated group presented increased transaminases (ALT/AST) and malondialdehyde levels in the plasma compared to controls. Lipid peroxidation, glutathione reductase and superoxide dismutase levels were increased in the plasma and arteries of the APAP group. Nevertheless, glutathione level was reduced as compared to control group. The vasodilation response to acetylcholine and sodium nitroprusside (0.1 nM to 10 µM) was also impaired after APAP treatment; however, the vascular relaxation was restored after treatment with vitamin C (100 µM). Arteries from the APAP group presented reduced wall thickness, collagen deposition, elastic fibers and increased immunoreactivity to nitrotyrosine. eNOS and sGC protein expression remained unchanged and were at similar levels as controls. These findings showed higher oxidative stress and impaired vasodilation in rats exposed to APAP. Furthermore, arteries presented reduced cell layers, collagen, elastin deposition and significantly increased immunoreactivity to nitrotyrosine after APAP treatment.
Assuntos
Acetaminofen/toxicidade , Aorta Torácica/efeitos dos fármacos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Estresse Oxidativo/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos , Animais , Antioxidantes/metabolismo , Aorta Torácica/metabolismo , Aorta Torácica/patologia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/metabolismo , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/patologia , Endotélio Vascular/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/enzimologia , Masculino , Ratos , Ratos WistarRESUMO
Azo dyes constitute the largest group of colorants used in industry and can pass through municipal waste water plants nearly unchanged due to their resistance to aerobic treatment, which potentially exposes humans and local biota to adverse effects. Unfortunately, little is known about their environmental fate. Under anaerobic conditions, some azo dyes are cleaved by microorganisms forming potentially carcinogenic aromatic amines. In the present study, the azo dye Disperse Orange 1, widely used in textile dyeing, was tested using the comet, Salmonella/microsome mutagenicity, cell viability, Daphnia similis and Microtox(®) assays. The human hepatoma cell line (HepG2) was used in the comet assay and for cell viability. In the mutagenicity assay, Salmonella typhimurium strains with different levels of nitroreductase and o-acetyltransferase were used. The dye showed genotoxic effects with respect to HepG2 cells at concentrations of 0.2, 0.4, 1.0, 2.0 and 4.0µg/mL. In the mutagenicity assay, greater responses were obtained with the strains TA98 and YG1041, suggesting that this compound mainly induces frameshift mutations. Moreover, the mutagenicity was greatly enhanced with the strains overproducing nitroreductase and o-acetyltransferase, showing the importance of these enzymes in the mutagenicity of this dye. In addition, the compound induced apoptosis after 72h in contact with the HepG2 cells. No toxic effects were observed for either D. similis or Vibrio fischeri.