Effect of albumin binding on bilirubin conjugation and toxicity in cell culture of a clonal strain of rat hepatoma cells.
A clonal strain of rat hepatoma cells (MH₁C₁) known to take up and conjugate bilirubin was incubated in media containing bilirubin and albumin in different molar ratios at a constant bilirubin concentration. The highest rate of bilirubin conjugation was found at a molar ratio of 1/1. Excess bilirubin markedly reduced both the conjugation of bilirubin and the incorporation of [14C]alanine, indicating a toxic effect on the cells. Excess albumin also depressed the formation of bilirubin conjugates, but incorporation of [14C]alanine proceeded at a normal rate, indicating that the reduced conjugation is probably due to stronger binding of bilirubin to albumin and reduced cellular uptake of bilirubin. Bilirubin bound to albumin at a molar ratio of 1/1 had no toxic effects on the cells as judged by cell morphology and conjugation capacity, even at a total bilirubin concentration as high as 680 μmol/l.
Bratlid
D
D
Pediatric Research Institute, University Hospital, Rikshospitalet, Oslo, Norway.
Rugstad
H E
HE
D000818:Animals; D001663:Bilirubin / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D002478:Cells, Cultured; D008114:Liver Neoplasms, Experimental; D051381:Rats; D012709:Serum Albumin / Q000737:chemistry / Q000378:metabolism; D018675:Toxicity Tests
D012709:Serum Albumin; D001663:Bilirubin