Urinary and biliary excretions of various phenol red derivatives in the anesthetized dog

¹ Department of Physiology and Department of Surgery, Yonsei University College of Medicine, Seoul, Korea

Excretion of phenol red derivatives, e.g., phenol red (PSP), bromphenol blue (BPB), and bromcresol green (BCG), in urine and bile was studied. After a single intravenous dose of dye, urine and bile samples were obtained every 30 min for 3 hr. Normally, 75% of PSP was excreted in urine in 3 hr; only 2.7% appeared in bile. Secretion of BPB and BCG was much faster in the liver than in the kidney. When Diodrast was administered intravenously after injection of a dye, excretions of all dyes in urine and bile were significantly reduced. A similar reduction in dye excretion was observed in hypothermic dogs in absence of Diodrast. Corresponding clearances and urine-to-plasma or bile-to-plasma concentration ratios were generally lowered by both Diodrast and hypothermia, suggesting that these dyes are secreted actively by a common transport system in both the kidney and liver. Excretion of these dyes and Bromsulphalein (BSP) was studied in the liver in bilaterally nephrectomized dogs. Dye excretion was greatest in BSP and decreased in the order BCG, BPB, and PSP, indicating that BSP is probably excreted by the liver through the same transport system as phenol red derivatives.