Acute renal failure. Histometrical and experimental investigations of factors causing oliguria.

Abstract

1) The anatomical changes of the kidney in acute renal failure were regarded to develop in the stage of partly recovered renal blood flow after temporary renal ischemia. 2) Similar anatomical renal changes were also observed in autopsy cases without serious clinical symptoms of renal impairment and without oliguria. 3) Renal secretion was theoretically treated and possible influences of anatomical changes on urine volume were discussed by means of histometrical investigation. Dilatation of tubular lumen was regarded to be one of the factors which contributed to reduce urine volume. 4) No difference in renal secretory activity was indicated by the histometrical investigation between oliguric and non-oliguric groups. 5) The cause of oliguria was sought in renal changes, which were accidental to renal secretory activity. Quantiative evaluation of injuries of the distal tubule revealed a clear correlation of tubular injuries to urine volume and made possible the separation of oliguric and non-oliguric groups. 6) The majority of the cases of acute renal failure was regarded to fall within the stage, where renal blood flow was more or less restored after temporary renal ischemia, but the kidney was still unable to excrete sufficient amount of urine on account of tubular leakage.