In order to investigate whether the function of distal nephron is disturbed in adenine-induced renal failure rats, we measured the urinary kallikrein level in adenine-ingesting rats fed on 0.75% adenine diet for 1 to 10 days. Administration of 0.75% adenine to rats significantly increased blood urea nitrogen level and urine volume, while the level of kallikrein along with the urinary excretions of urea and inorganic phosphate were significantly decreased. From these results, it is suggested that adenine-induced renal failure is caused by early deterioration of distal nephron as well as proximal nephron.