Spontaneous glomerular deposition of immunoglobulins for ACE (Angiotensin Converting Enzyme) induces spontaneous nephropathy in diabetogenic rats

We first discovered autoantibodies to ACE (angiotensin converting enzyme) in patients with type 2 diabetes mellitus^1^. The antibodies were positive for 64.5% of the patients with diabetes and were positive in 83.3% in the early stage of clinical diabetic nephropathy. In addition, in genetically diabetogenic OLETF (Otsuka Long-Evans Tokushima Fatty) rats^2^, one of the characteristics of which strain is spontaneous nephropathy resembling those of human type 2 diabetes, and in control LETO rats^2^, immunization with rabbit lung ACE developed glomerulopathy similar to that seen in diabetics^3^. Also, in normal New Zealand white rabbits, immunization with the rabbit lung ACE induced glomerular changes similar to those seen in diabetic nephropathy^3^. In this study, renal tissues identical to those examined in research of diabetic nephropathy by PAS staining and electron microscope in preceding study^3^, were examined by immunostaining methods, only to prove that the diabetic glomerular changes may occur by immunization with ACE, not by non-specific responses to ACE, in non-diabetogenic rats and rabbits.