Effects of rose bengal on bile secretion in the rabbit: inhibition of a bile salt-independent fraction.

The authors have studied the influence of rose bengal, and, by comparison, of uranin, on choleresis in the rabbit. Uranin induced an increase in bile flow and a decrease in bile salt concentration in bile. These results are consistent with an osmotic mechanism, as proposed by Sperber (1959). By contrast, rose bengal induced a marked decrease in bile flow and an increase in bile salt concentration. In rose bengal-treated animals (30 mumoles per kilogram body weight intravenously), bile flow was 65% lower and bile salt concentration 95% higher than in control animals studied during the same periods. The relationship between bile flow and bile salt excretion is consistent in the rabbit, with the existence of a bile salt-independent secretion of 60 mg per minute per kilogram body weight, that is, 60% of bile flow. In rose bengal-treated animals, this fraction was only 15 mg per minute per kilogram body weight. It is concluded that rose bengal inhibits the bile salt-independent fraction. Rose bengal, as other phtalein dyes, is excreted by the liver cells. Its effect on the bile salt-independent fraction suggests that this fraction is secreted by the hepatocytes.