[Simultaneous comparative renal clearances and renal iodo (I125)-hippurate in man (author's transl)]

In 111 Patients with a wide range of renal function (normal to advanced renal failure) the renal clearances of Na-paraaminohippurate (CPAH) and of Na-orthojodohippurate--J125(COJ(J125(H) have been simultaneously determined under standardized clearance conditions. We found a significant correlation between the 2 parameters, defined by the equation CPAH = 1.11.COJ(J125)H. The scatter of the single observations however is considerable and hence the +/- 2Sy range is very large. The difference between the 2 clearances is not die to a competition at the same tubular carrier, since adding inactive carrier of OJH does not improve the ratio of the 2 clearances: CPAH = 1.13.COJ(J125)H. Rather the renal extraction of OJ(J125)H(EOJ(J125)H is considerably lower (74% than EPAH (90%). Our datas suggest that OJ(J125)H is not a suitable indicator to replace PAH for measurements of real renal plasma flow.