抄録
The Phenolsulfonphthalein excretion test (PSP-U), para-aminohippurate (PAH) and endogenous creatinine clearance tests are now usually and widely applied for measurement of renal function, but accurate urine collection is necessary in these procedures. Calculation of the Plasma Phenolsulfonphthalein Index (PSP-I), reported by Gault 1966, is a new measurement of renal function without urine collection. In this report, the purpose is to discuss the procedures of this new function test in detail.(1) According to the original method by Gault, turbidity often appeared in the sample in the terminal phase of reading of PSP concentration. We succeeded in excluding this turbidity by warming the sample up to 40∼45°C.(2) Plasma and serum phenolsulfonphthalein concentration were always stable, and showed almost the same values in any conditions. So, serum phenol sulfonphthalein concentration is used in this study.(3) The precise repeatability by this method was demonstrated biochemically and biologically.(4) The normal range of PSP-I in this younger age group (18 to 50 years old, 50 cases) appeared to be 20.01±3. 45 (S. D) unit, with above 16 unit in great majority. Therefore we considered 16 unit as lower limit of PSP-I normal range.(5) The mean value of PSP-I in 11 normal elder subjects, (aged 51 to 67 years old) was 17.1±2.41 (S. D.) unit. Decrease of PSP-I with aging was observed in these normal elder subjects. Calculation of PSP-I is a easy procedure for renal function test without urine collection and with precise repeatability. Therefore, in cases of patients whose urine collections on time are difficult, and then who have renal diseases with dead space, this procedure is considered to be the most useful method.
