Assessment of early renal damage in diabetic rhesus monkeys

The objectives of the study were to improve the model system of diabetic nephropathy in nonhuman primates and assess the early renal damage. Diabetes was induced in monkeys by streptozotocin, and the animals were administered exogenous insulin to control blood glucose (BG). Animals were divided into four groups, including the normal group (N = 3), group A (streptozotocin diabetic model with control of BG < 10 mmol/L, N = 3), group B (streptozotocin diabetic model with control of BG between 15 and 20 mmol/L, N = 4), and group C (streptozotocin diabetic model with control of BG between 15 and 20 mmol/L and high-sodium and high-fat diet, N = 4). The following parameters were evaluated: (1) blood biochemistry and routine urinalysis, (2) color Doppler ultrasound, (3) angiography, (4) renal biopsy, and (5) renal fibrosis-related gene expression levels. Animals in group C developed progressive histologic changes with typical diabetic nephropathy resembling diabetic nephropathy in human patients and exhibited accelerated development of diabetic nephropathy compared with other nonhuman primate models. Significant changes in the expression of the Smad2/3 gene and eNOS in renal tissue were also observed in the early stage of diabetic nephropathy. In conclusion, our model is an excellent model of diabetic nephropathy for understanding the pathogenesis of diabetic nephropathy.