Enhanced Urinary Excretion of Lipid Metabolites Following Exposure to Structurally Diverse Toxicants: A Unique Experimental Model for the Assessment of Oxidative Stress

2011 ◽  
pp. 481-495
Author(s):  
Francis C. Lau ◽  
Manashi Bagchi ◽  
Shirley Zafra-Stone ◽  
Debasis Bagchi
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Suvanjaa Sivalingam ◽  
Emil List Larsen ◽  
Daniel H. van Raalte ◽  
Marcel H. A. Muskiet ◽  
Mark M. Smits ◽  
...  

AbstractGlucagon-like peptide 1 receptor agonists have shown cardioprotective effects which have been suggested to be mediated through inhibition of oxidative stress. We investigated the effect of treatment with a glucagon-like peptide 1 receptor agonist (liraglutide) on oxidative stress measured as urinary nucleic acid oxidation in persons with type 2 diabetes. Post-hoc analysis of two independent, randomised, placebo-controlled and double-blinded clinical trials. In a cross-over study where persons with type 2 diabetes and microalbuminuria (LIRALBU, n = 32) received liraglutide (1.8 mg/day) or placebo for 12 weeks in random order, separated by 4 weeks of wash-out. In a parallel-grouped study where obese persons with type 2 diabetes (SAFEGUARD, n = 56) received liraglutide (1.8 mg/day), sitagliptin (100 mg/day) or placebo for 12 weeks. Endpoints were changes in the urinary markers of DNA oxidation (8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG)) and RNA oxidation [8-oxo-7,8-dihydroguanosine (8-oxoGuo)]. In LIRALBU, we observed no significant differences between treatment periods in urinary excretion of 8-oxodG [0.028 (standard error (SE): 0.17] nmol/mmol creatinine, p = 0.87) or of 8-oxoGuo [0.12 (0.12) nmol/mmol creatinine, p = 0.31]. In SAFEGUARD, excretion of 8-oxodG was not changed in the liraglutide group [2.8 (− 8.51; 15.49) %, p = 0.62] but a significant decline was demonstrated in the placebo group [12.6 (− 21.3; 3.1) %, p = 0.02], resulting in a relative increase in the liraglutide group compared to placebo (0.16 nmol/mmol creatinine, SE 0.07, p = 0.02). Treatment with sitagliptin compared to placebo demonstrated no significant difference (0.07 (0.07) nmol/mmol creatinine, p = 0.34). Nor were any significant differences for urinary excretion of 8-oxoGuo liraglutide vs placebo [0.09 (SE: 0.07) nmol/mmol creatinine, p = 0.19] or sitagliptin vs placebo [0.07 (SE: 0.07) nmol/mmol creatinine, p = 0.35] observed. This post-hoc analysis could not demonstrate a beneficial effect of 12 weeks of treatment with liraglutide or sitagliptin on oxidatively generated modifications of nucleic acid in persons with type 2 diabetes.


Life Sciences ◽  
2021 ◽  
Vol 272 ◽  
pp. 119194
Author(s):  
Diva de Aguiar Magalhães ◽  
Jalles Arruda Batista ◽  
Stefany Guimarães Sousa ◽  
Jayro dos Santos Ferreira ◽  
Lauanda da Rocha Rodrigues ◽  
...  

2010 ◽  
Vol 25 (3) ◽  
pp. 304-310 ◽  
Author(s):  
Cleber Rosito Pinto Kruel ◽  
Luis Felipe Ribeiro Pinto ◽  
Tania Cristina Moita Blanco ◽  
Theresa Christina Barja-Fidalgo ◽  
Levi Lourenzo Melo ◽  
...  

PURPOSE: To study the expression of heme-oxygenase-1 (HO-1), an enzyme induced by oxidative stress, in specimens obtained from an experimental model in rats that evaluated the role of gastric and duodenal reflux in esophageal carcinogenesis. METHODS: Esophageal specimens embedded in paraffin obtained from different experimental groups of rats were used for immunohistochemistry analysis of HO-1 expression. The rats had been divided into the following groups and were killed after 22 weeks: (1) cardioplasty to induce acid reflux; (2) esophagoduodenal anastomosis to induce duodenal reflux; (3) no treatment; (4) cardioplasty + diethylnitrosamine (DEN); (5) esophagoduodenal anastomosis + DEN; and (6) DEN. The study sample comprised 3 specimens from each group with the most severe histopathological lesions found on each study branch. RESULTS: The expression of HO-1 was seen only in rat specimens submitted to esophagoduodenal anastomosis (Groups 2 and 5), and the analysis of mean fluorescence intensity revealed a significant increase of HO-1 expression (4.8 and 4.6 fold, respectively) when compared with the control group (Group 3) (p<0.05). The main target for HO-1 induction was the inflammatory cells inside the tumor or in subepithelial areas. Rats exposed to gastric reflux had no HO-1 expression. CONCLUSION: Reflux esophagitis induced by reflux of duodenal contents, which provoked considerable oxidative stress, may play an important role in esophageal carcinogenesis. Acid reflux did not induce oxidative stress in this experimental model.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Nicolás F. Renna ◽  
Emiliano R. Diez ◽  
Carina Lembo ◽  
Roberto M. Miatello

The objective of this work was to demonstrate the role of COX-2 enzyme at the vascular in experimental model of metabolic syndrome. SHR male WKY rats were employed; they were distributed in 8 groups (n=8each): control (W); W + L: WKY rats receiving 20 mg/kg of lumiracoxib by intraesophageal administration; SHR; SHR + L: SHR + 20 mg/kg of lumiracoxib by intraesophageal administration; Fructose-Fed Rats (FFR): WKY rats receiving 10% (w/v) fructose solution in drinking water during all 12 weeks; FFR + L: FFR + 20 mg/kg of lumiracoxib by intraesophageal administration; Fructose-Fed Hypertensive Rats (FFHR): SHR receiving 10% (w/v) fructose solution in drinking water during all 12 weeks; and FFHR + L: FFHR + 20 mg/kg of lumiracoxib by intraesophageal administration. Metabolic variables, blood pressure, morphometric variables, and oxidative stress variables were evaluated; also MMP-2 and MMP-9 (collagenases), VCAM-1, and NF-κB by Westernblot or IFI were evaluated. FFHR presented all variables of metabolic syndrome; there was also an increase in oxidative stress variables; vascular remodeling and left ventricular hypertrophy were evidenced along with a significant increase in the expression of the mentioned proinflammatory molecules and increased activity and expression of collagenase. Lumiracoxib was able to reverse vascular remodeling changes and inflammation, demonstrating the involvement of COX-2 in the pathophysiology of vascular remodeling in this experimental model.


Inflammation ◽  
2020 ◽  
Vol 43 (4) ◽  
pp. 1411-1422
Author(s):  
S. Sheethal ◽  
M. Ratheesh ◽  
Svenia P. Jose ◽  
S. Asha ◽  
I. M. Krishnakumar ◽  
...  

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