Effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin on the biliary excretion of indocyanine green in rat.

Chlorinated dibenzodioxins have been found as contaminants of various technical chlorinated compounds such as 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), which are widely used in agriculture. The dioxin contaminants may be involved in various pathologic states resulting from exposure to technical chlorinated compounds (1, 2). Liver necrosis has been observed in the animals which were treated with derivatives of chlorophenol (3) or other chlorinated compounds (4), and it was suggested that liver necrosis-causing factors were present in these compounds. In view of the above observation, the present study was undertaken to investigate whether 2,3,7,8-tetrachloro-pdibenzodioxin (TCDD) has any effect on the hepatobiliary function of rat. Biliary excretion of indocyanine green (ICG) was used as the index of function. The dye was chosen because it is completely and rapidly excreted by normal liver into the bile by an active process (5).