Fluorometric study of serum in patients with chronic renal failure.

Sera from 84 uremic patients (53 on conservative treatment and 31 on hemodialysis) were studied spectrofluorometrically in comparison with 20 normal subjects and 11 jaundiced patients. Serum fluorescence in patients with chronic renal failure was significantly higher than in normals and patients with jaundice. Two types of serum fluorescence spectra (A and B) were predominant (93%) and all the patients who were free of any medication for more than two months exhibited the type A spectrum. The intensity of fluorescence was in parallel with the serum creatinine levels. Dialysis experiments of uremic serum in vitro showed that the substance(s) responsible for its fluorescence is dialyzable. Moreover hemodialysis caused a significant decrease in the intensity of serum fluorescence in dialyzed patients. Administration of pyridoxine intravenously caused quite different results in normal subjects and uremic patients. Namely normals presented a transient (for several minutes) increase in serum fluorescence whereas uremics showed a higher and more permanent increase which lasted for several days.