AMP-Activated Protein Kinases/metabolism; Diabetes Mellitus, Experimental/metabolism; Mitochondria/metabolism; Superoxides/metabolism; AMP-Activated Protein Kinases/deficiency; AMP-Activated Protein Kinases/genetics; Aminoimidazole Carboxamide/analogs & derivatives; Aminoimidazole Carboxamide/pharmacology; Animals; Diabetes Mellitus, Experimental/pathology; Diabetic Nephropathies/metabolism; Diabetic Nephropathies/pathology; Enzyme Activation/drug effects; Humans; Kidney/drug effects; Kidney/metabolism; Male; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Mice, Knockout; Mitochondria/drug effects; Pyruvate Dehydrogenase Complex/metabolism; Ribonucleotides/pharmacology; Rotenone/pharmacology; Superoxide Dismutase/deficiency; Superoxide Dismutase/genetics; Superoxide Dismutase/metabolism