[Improvement of the endogenous creatinine clearance by blocking the tubules].

In the endogenic creatinine clearance at present a blocking of the tubuli with phenol red cannot be achieved. The elimination follows in the 20th and 40th minute after the injection of a simple exponential function and thus allows the determination of the half-life period. The phenol red 60/60 value lies in the phase of the backflow of phenol red from the space of distribution.