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May 13, 1968

Phenolsulfonphthalein Excretion Test

Author Affiliations

From the departments of medicine of the Chicago Medical School, University of Health Sciences; Mount Sinai Hospital Medical Center (Dr. Freedman); and Cook County Hospital, Chicago (Dr. Dunea).

JAMA. 1968;204(7):621-622. doi:10.1001/jama.1968.03140200061019

The phenolsulfonphthalein (PSP [phenol red]) excretion test was developed by Rowntree and Geraghty in 1910, when chemical determinations were generally unavailable, and assessment of renal function was essentially limited to examination of the urine for protein and sediment. Some measure of popularity, however, had been achieved by tests which depended on the urinary excretion of a foreign dye, such as indigo carmine or methylene blue. The use of phenolsulfonphthalein for this purpose evolved from a search for a subcutaneous purgative, when the high urine excretion and the lack of toxicity of the dye became apparent.1

Significance and Usefulness  Phenolsulfonphthalein early assumed significance in several areas. It became one of the first widely used tests for measurement of renal function. The presence of phenolsulfonphthalein in the cortex of a dog with absent glomerular filtration provided the first acceptable evidence of tubular secretion by the mammalian kidney. Recognition of the removal