en Histopathology Histopathology Original Article Original Article Diabetes mellitus is a progressive disease. Most investigators have focused on glomerular changes in diabetic kidney and non-glomerular alterations have been less attended. The present study has been conducted to find early non-glomerular histological changes in diabetic renal tissue. Twenty male Wistar rats weighting 200-250 g were used for the diabetic group. Diabetes mellitus was induced by single injection of Alloxan. After 8 weeks, paraffin embedded blocks of kidneys were prepared for evaluating the histological changes due to diabetes. Histological study showed the deposit of eosinophilic materials in the intermediate substantial of medulla and thickening of renal arterial wall in the kidney of 70% of diabetic rats. The average weight of kidneys increased when compared to non diabetic animals. Furthermore, the amount of blood flow in arteries of all diabetic kidneys has been enhanced. The present study demonstrates some early renal histological changes in diabetes mellitus which were earlier compared to those reported previously. Diabetic nephropathy is a progressive disease and renal care design can help better prognosis achievement. Key words: Diabetes mellitus, kidney, alloxan 11 15 http://ijmcmed.org/browse.php?a_code=A-10-63-4&slc_lang=en&sid=1 Mohsen Pourghasem mpourghasem@hotmail.com 10031947532846003525 10031947532846003525 No Cellular and Molecular Biology Research Center (CMBRC), Babol University of Medical Sciences, Babol, Iran. Ebrahim Nasiri ebrahimnasiri@yahoo.com 10031947532846003526 10031947532846003526 Yes Department of Anatomical Sciences, Gilan University of Medical Sciences. Rasht, Iran. Hamid Shafi dr_hamidshafi@yahoo.com 10031947532846003527 10031947532846003527 No Department of Urology, Babol University of Medical Sciences, Babol, Iran.