Abstract

Hepatic and renal excretory transport of four food dyes was examined. In the intact animal, excretion of dyes by these organs is insignificant because of limited absorption from the intestinal tract. To establish that significant hepatic and renal transport can occur, isolated perfused rat livers and surviving slices of rabbit renal cortex were used as experimental models. Amaranth, sunset yellow and tartrazine were transported by liver and kidney against a concentration difference by a mechanism which could be inhibited by probenecid. In kidney slices, 4-aminohippurate depressed accumulation of these three dyes. It is suggested that amaranth, sunset yellow and tartrazine participate in the same hepatic and renal mechanisms which transport organic anions such as hippurates. In contrast, brilliant blue was not transported by kidney, although transport (probably of a metabolite) did occur in the liver.