Premium
Foetal bile pigment handling after administration of [ 14 C] haemin
Author(s) -
Jackson Benjamin T.,
Lester Roger,
Little Joanna M.,
Piasecki George J.,
Rauschecker Helmut F. J.,
Smith Paul M.
Publication year - 1973
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.1973.sp010294
Subject(s) - pigment , chemistry , organic chemistry
1. Advanced techniques for intra‐uterine surgery were used to study haem degradation in foetal sheep prepared in utero with indwelling jugular, carotid and biliary cannulas. [ 14 C]haemin was administered I.V. to the foetus, and plasma disappearance, biliary excretion, placental transfer and tissue distribution of radioactivity were measured over a 5–8 hr period. 2. 8–30% of the 14 C‐label was recovered in foetal bile, about 40% of this as bilirubin and the rest as unidentified [ 14 C]haemin derivatives. 4–21% was transferred across the placenta, appearing in maternal bile almost exclusively as [ 14 C]bilirubin. Excretion of 14 C‐label totalled 18–33%. 3. Six adult sheep infused with [ 14 C]haemin excreted 19–49% of the dose in the bile over 8 hr, one third as bilirubin. 4. The amount of endogenous bilirubin excreted per unit time/unit wt. of foetal liver increased with increasing foetal wt. 5. It is concluded that near‐term foetal sheep have a maturing mechanism for haem catabolism. Haem is partially excreted in foetal bile as bilirubin. Another fraction is transferred across the placenta, probably after prior conversion to bilirubin. The remainder is converted to un‐identifiable end‐products. Total excretion is approximately as effective as that in adults.