Glutathione peroxidase

Muscle lysates were used to determine total antioxidant capacity (TAC) (Cayman, MI, USA, Cat# 709001), and the enzymatic activities of catalase (Cayman, MI, USA, Cat# 707002), glutathione peroxidase (Cayman, MI, USA, Cat# 703102), and glutathione reductase (Cayman, MI, USA, Cat# 703202) according to the manufacturer’s instructions for each assay kit. Enzymatic activity was normalized by the quantity of protein (mg) used in each essay. Superoxide dismutase activity was also assessed using a colorimetric assay kit (Cayman, MI, USA, Cat# 706002), but the interference of the reagents used in the homogenization of muscle samples prevented the acquisition of reliable data. Therefore, SOD activity is not reported herein.

Superoxide dismutase (SOD) (Cayman Chemical, USA), glutathione peroxidase (GPx) (Cayman Chemical, USA) and catalase (CAT) (Abbexa Ltd, UK) enzyme activity were measured in homogenised kidney tissue according to each kit manufacturer's procedures and recommendations. Renal tissue malondialdehyde (MDA) level, a lipid peroxidation marker, was assessed by a method described by Buege and Aust [26 (link)].

Total antioxidant
capacity (TAC)
(Cell Biolabs, CA, USA) and catalase (CAT), glutathione peroxidase
(GPx) (Cayman Chemical, MI, USA), superoxide dismutase (SOD) (Arbor
Assays, MI, USA), and glutathione reductase (GR) (Biovision, CA, USA)
activities were measured in plasma by colorimetric assays following
the manufacturer’s instructions. Absorbance values were measured
with the CLARIOstar plus microplate reader (BMG Labtech, Ortenberg,
Germany). Plasmatic levels of oxLDL were measured by the mouse oxidized
low density lipoprotein (oxLDL) ELISA kit (MyBioSource, CA, USA) according
to the manufacturer’s indications. Absorbance values at 450
nm were measured with the Multiskan FC microplate photometer (Thermo
Scientific). The representative standard curves are showed in Supporting Information, Figure S1, and the sensitivity and inter/intra assay precision are
shown in Supporting Information, Table S2.