EXCRETION OF BILE ACIDS IN ERYTHROBLASTOSIS FOETALIS

The excretion pattern of intramuscularly injected cholic acid-24–¹⁴C was studied for 4 days after the injection in 10 cases of erythro-blastosis (EB). Seven patients with EB and raised serum conjugated bilirubin excreted 3643% of the injected isotope in the urine, whereas the amounts of isotope in the faeces varied greatly. In 3 cases without raised serum conjugated bilirubin less isotope was recovered in the urine and always more than 10% of injected isotope was recovered in the faeces. Cholic acid-24–¹⁴C was excreted essentially unchanged in all cases but in conjugated form. In all cases of EB the urine was found to contain bile acids, chiefly cholic acid. The infants with EB associated with cholestasis excreted 4.8–132.3 μmol of these acids per day; the corresponding values in the absence of cholestasis being 0.4–0.9 μmol per day. In the infants with physiological jaundice the excretion ranged from less than 0.01 to 0.7 μmol per day; the correspondign values in the 2 patients with hyperbilirubinaemia were about 0.2 μmol per day. The infants with EB associataed with cholestasis were found to excrete as large amounts of bile acids in the urine as the infants with intrahepatic cholestasis. These findings strongly suggest that increased serum conjugated bilirubin, irrespective of the patho-genesis of the liver damage, is associated with an impaired bile acid excretion to the intestine. EB without increased serum conjugated bilirubin did not seem to alter the bile acid metabolism, since the urinary excretion of cholic acid and chenodeoxycholic acid in these cases was practically the same as in jaundiced newborn infants.