Histological Changes in Renal Tissue During the Onset of Diabetes Mellitus in Rats and Association with Aging

Diabetes Mellitus (DM) favors kidney remodeling, leading to diabetic kidney disease (DKD). Kidney histological alterations are identified after DKD installation, but have not been studied in the early stage of DM. We studied renal remodeling in Wistar rats at the early stage of DM, before DKD development, investigating alterations indicating a poor prognosis and whether age is an impact factor. Diabetes was induced with Alloxan. Groups: adult diabetic (DMA), elderly diabetic (DMI), adult sham control (CSA), and elderly sham control (CSI). After 30 days of confirmed diabetes, blood, urine, and kidney were collected. Both diabetic groups presented normal renal function. DMA and DMI showed tubular infiltration and hypertrophy, decreased Bowman's space, and reduced glomerular area. A decrease in the glomeruli number was observed in the DMI. An inverse correlation between the glomeruli number and the ApoB/ApoA ratio was observed on DMA. We conclude that histological changes characteristic of DKD can be observed in the early stages of DM, and age can have a role in the injury intensity. Tubular and glomerular alterations occur during DM installation and continue to evolve as DKD develops. Therefore, targeting the prevention of kidney remodeling could be a good therapeutic approach to prevent DKD.