Renal function is ameliorated in a diabetic nephropathy rat model through a duodenal-jejunal bypass

Diabetes surgery is growing in popularity and has been shown to have marked effects on diabetes. However, several studies have shown it may induce some renal injury, and, currently, the impact of diabetes surgery on renal function is unclear. In this study, we examined renal function and histological changes in rats with diabetic nephropathy (DN) following a duodeno-jejunal bypass (DJB) operation.

Rats with streptozotocin (STZ)-induced diabetes were randomly assigned to 3 groups: DJB group (DJB), Sham-DJB group (S-DJB) and diabetes group (DM). Six age-matched normal rats were assigned as the control group. DJB and sham surgery were performed. Body weight, food intake, glucose levels, lipid parameters, cystatin C (Cys_C) levels, serum and urinary creatinine, 24h urine albumin excretion rate (UAER) and glomerular filtration rate (GFR) were measured. Histological analysis and immunohistochemical studies of renal sections were also performed.

DJB ameliorated renal function by improving UAER, GFR and Cys_C levels 4 and 8 weeks after surgery. It also improved lipid metabolism by decreasing fasting total serum cholesterol (TC) and triglyceride (TG) levels. Immuno-staining of synaptopodin showed podocyte injury was also improved in DJB glomeruli compared with sham and DM groups. Histological analysis showed that the mesangial expansion was not significantly prevented 8 weeks after DJB surgery.

DJB ameliorated renal function in UAER and GFR but not mesangial expansion in a DN rat model. The improvement of renal function may be attributed to reversing the injury or loss of podocytes after DJB surgery.