Oxidative Stress Markers and NAG
Blood samples were taken into biochemistry contains tubes and were
centrifuged at 3000 g for 15 minutes to obtain serum. All serum samples
stored at -80 °C until experiments got started. Total antioxidant
status(TAS) and total oxidant status(TOS) levels were measured using
commercially available kits (Relassay, Turkey) according to Erel’s
assay. OSI was defined as TOS to TAS ratio was calculated as follows:
OSI (arbitrary unit) = [(TOS, μmol H2O2 equivalent) / (TAS, μmol
Trolox equivalent] × 100). [18,19] Urine samples from each patient
were collected just before scintigraphy and within three days after
scintigraphy. Urinary NAG (N-acetyl-glucosaminidase) was analyzed using
a photometric method (Cobbas 8000 autoanalyzer, Diazyme Laboratories,
Poway, CA). TAS, TOS and, creatinine levels of urine samples were also
studied, OSI was calculated. The ratio of NAG, TAS, and TOS values in
spot urine to urine creatinine values were used to avoid any effect on
dilution and concentration.