Blood and kidney sampling

Animals were sacrificed at 24 h after exhaustive exercise in all groups. Anesthesia was induced with 2% isoflurane inhalation at 0.8 L/min, and maintained with 1% at 0.8 L/min. Blood samples were obtained using heparin via the abdominal aorta, centrifuged at 2600 g for 10 min and plasma was stored at –80°C until analysis. The kidneys were removed and the right kidneys were snap frozen by immersing the samples in liquid nitrogen and stored at –80°C until analysis; the left kidneys were frozen in Tissue-tek Crymold (Sakura, Torrance, CA, USA) filled with OCT compound (Sakura) by immersing the samples in precooled isopentane at –80°C.