Cobas 501

Serum creatinine, urea, and fasting glucose were analyzed by spectrophotometric method on Olympus AU 2700 (Beckman Coulter Corporation, Tokyo, Japan). HbA1C was analyzed using the Tosoh G 8 instrument (Tosoh Corporation, Tokyo, Japan) by high-performance liquid chromatography method. Thiol, disulfide, IMA, and ferroxidase tests were analyzed in the Cobas 501 (Roche, Mannheim, Germany). The native thiol (-SH) and total thiol (-SH + -SS) were analyzed and disulfide (-S-S), disulfide/native thiol, disulfide/total thiol, and native thiol/total thiol values were obtained by calculation. “Modified Ellman method” of Erel et al. [8 (link)] was used for total and native thiol measurement. IMA was detected with a quick colorimetric method adapted by Bar-Or et al. [18 (link)] The method defined by Neselioglu et al. [13 (link)] was used to analyze ferroxidase activity.

Wistar-Hannover albino adult female rats (weighing 250–300 g, n=21) were divided into three groups. During the experiment, all groups were held in a standard postoperative care room (at 20–25°C, 50–60% humidity, in polycarbonate cages) with standard feeding conditions and 12-h light and dark cycles.
A commercial kit was used for measurement of total antioxidant status (TAS) and total oxidative status in tissue.[18 (link),19 (link)] The protein level of tissue was determined using the Lowry method.[20 (link)] Oxidative Stress Index (OSI) was obtained by dividing total oxidant capacity (TOS) values by TAS values (OSI [Arbitrary Unit] = [TOS, μmol H₂O₂ eq/L]/[TAS, μmol Trolox eq/L]).
Serum thiol SS was measured by an automatic analyzer (Roche, cobas 501, Mannheim, Germany) using the method created by Erel and Neşelioğlu. In this method, SS bonds in the sample were converted to functional thiol groups by NaBH4. The total thiol (TT) content in the sample was calculated using Ellman reagent. The serum SS level was determined with the formula (serum TT − serum native thiol [NT])/2.[5 (link)]

The blood samples were centrifuged at 2300×g for 10 min and stored at −80 °C until analysis. Serum TDH tests were measured by a recently described method using an automated clinical chemistry analyzer (Roche, Cobas 501, Mannheim, Germany) (15 (link)). Disulfide bonds were reduced to form free functional thiol groups with sodium borohydride. Unused reductant sodium borohydride was consumed and removed with formaldehyde to prevent the reduction of 5,5’-dithiobis-(2-nitrobenzoic) acid, and all of the thiol groups including reduced and native thiol groups were identified after the reaction with 5,5’-dithiobis-(2-nitrobenzoic) acid. Half of the difference between the total thiols and native thiols provides the dynamic disulfide levels. Index 1, 2 and 3 were calculated as follows; index 1= (disulfide/native thiol) x 100, index 2 = (disulfide/total thiol) x 100, index 3 = (native thiol/total thiol) x 100.