The biliary excretion of tartrazine. Sex differences in the rat and species differences in the rat, guinea-pig and rabbit

Abstract
The excretion of tartrazine in the bile and urine has been studied in biliary cannulated rats, rabbits and guinea-pigs. This dye is excreted unchanged by these species. In the rat a sex difference in the relative amounts of tartrazine excreted in bile and urine has been found. Male rats excrete in 3 h about 17 % of an intravenous dose (50 μmol/kg) in the bile and about 70% in the urine, whereas females excrete about 40 and 45 % respectively. The biliary excretion of tartrazine in the rat appears to be influenced by dose level, for at the lower level of 4.5 μmol/kg male rats excrete about 9 % of an intravenous dose in the bile and 64% in the urine in 3 h, the corresponding values for female rats being 30% and 50%. There is also a species difference in the extent of biliary excretion of tartrazine (50 μmol/kg intravenously). The female rat and female guinea-pig excrete in 3 h about 40 % of the dose in the bile and a similar amount in the urine whereas the female rabbit excretes only 6% in the bile and nearly 70% in the urine. Previous work in this laboratory has shown that molecular weight is an important factor in the biliary excretion of foreign compounds and the present results fit in with this view.