Autoregulation of flow in isolated rat kidney in the absence of red cells

Abstract
A method was devised for the perfusion of isolated rat kidney without interruption of flow. The flow pattern obtained with cell-free dextran at a constant pressure showed a stable period of maximal flow for about 15–30 minutes. Thereafter the flow resistance of the kidney increased continuously. Autoregulation was maximal during the period of maximal flow, but thereafter deteriorated until it disappeared completely. The autoregulation was diminished by Priscoline and completely but reversibly abolished by procaine. It was concluded that autoregulation involves a physiological rather than a ‘cell separation’ mechanism.