High body
iron levels are found in
type 2 diabetes mellitus (DM).
Iron excess leads to tissue injury through
free radical formation. We investigated the effect of
iron restriction on renal damage in Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a model of type 2 DM. OLETF rats (n = 18) were divided into three groups
at 10 weeks of age: high fat diet containing 8% NaCl (HFS, n = 6), HFS diet with
iron restricted (HFS + IR, n = 6), and HFS with
hydralazine (HFS + Hyd, n = 6). Long-Evans Tokushima (LETO) rats served as control.
Iron restriction decreased
hemoglobin levels, systolic blood pressure, and urinary excretion of
protein and
8-hydroxy-2'-deoxyguanosine in the OLETF rats fed with HFS diet. Compared to the HFS group, the expression of
desmin, renal glomerular injury marker and
iron deposition in the renal tubules were attenuated in the HFS + IR group but not in the HFS + Hyd group at 26 weeks of age. Moreover, renal
hypoxia (evaluated as
pimonidazole adducts) was improved in the HFS + IR group compared to the HFS group in spite of
anemia.
Iron restriction prevented the production of
reactive oxygen species and the development of early stage nephropathy in OLETF rats.
Iron restriction may be beneficial in prevention of nephropathy in type 2 DM.