Histopathological and immunopathological studies on renal involvement in non-obese diabetic (NOD) mice

Histopathological and immunopathological studies on kidney tissues in non-obese diabetic (NOD) mice were performed to elucidate the progressive mechanisms of glomerular injury and proteinuria. Thickening of the glomerular basement membrane (GBM) was observed in the group of NOD mice with increased levels of glycohemoglobin Al (HbAl). Further, the immunofluourescence findings for the NOD mice were almost equivalent to the findings in human diabetic nephropathy. Additionally, polyethyleneimine (PEI) particles in the GBM of NOD mice decreased gradually as the amount of proteinuria increased. These observations suggest that the GBM thickening in NOD mice might be correlated with altered physicochemical characteristics of the renal tissue and/or have some affinity for immunoglobulins and complement to the GBM, and that the proteinuria in these mice might be due to such GBM thickening and a decrease in the negative charge barrier on the GBM. The present histopathological and immunopathological study of NOD mice thus provided useful data and, since the findings in humans are similar, should aid in evaluating the pathogenesis and progressive factors of the renal involvement in patients with diabetes mellitus.