##Iron assay
Renal tissue samples (10 mg) from each group were washed with cold
normal saline after incision. A vibrating homogenizer was immediately
applied to add cold brine for tissue homogenization. In addition, the
collected cells were homogenized with ultrasonic cell interfering agent.
After centrifugation for 10 min, the supernatant was collected, and the
iron concentration in tissues and cells was determined with an iron
content determination kit (BioAssay, Hayward, CA, USA). According to the
manufacturer’s instructions, a sufficient amount of the working reagents
was prepared, the working reagents were transferred with 96-well plate,
and supernatant was collected from a 96-well plate. The optical density
determination wavelength of the iron content determination kit was 590
nm.