Peter V. D. Barrett

Bilirubin Turnover Studies in Normal and Pathologic States Using Bilirubin-14C

Abstract Bilirubin-14C in tracer quantities was administered to 26 patients in 29 studies to determine the plasma bilirubin-14C specific activity disappearance rates. Unconjugated bilirubin was sep...

Effects of Caloric and Noncaloric Materials in Fasting Hyperbilirubinemia

Fasting hyperbilirubinemia (FHB) has previously been shown to be rapidly reversed by the ingestion of a mixed diet. This study examines the effect of carbohydrate, fat, amino acids, and noncaloric materials on FHB. After an initial fast of 15 to 39 hr, caloric and noncaloric materials were administered by mouth or vein to 13 subjects, and the total serum bilirubin (TSB) was determined frequently for 4.5 hr. Only oral glucose reversed FHB; the TSB did not change significantly from control studies after oral saline, mannitol, amino acids, and fat. In contrast, intravenous infusion of glucose resulted in a significant increase in TSB which could not be explained by osmotic or intravascular volume changes, and was nonspecific, since similar effects resulted from infusions of mannitol and amino acids. The results of this study demonstrate that oral glucose reverses FHB, and that under the conditions of these experiments other nutrients and noncaloric materials are ineffective. In contrast, intravenous glucose, mannitol, and amino acids increase the TSB by unknown mechanisms.

Assay of hepatic glucuronyl transferase activity using [14C]bilirubin as substrate

Abstract A method for the assay of hepatic glucuronyl transferase activity using [ 14 C]bilirubin as substrate has been developed. Under the conditions of the assay, the conjugation products from normal rats and guinea pigs have been found to react with diazo reagent to form azo-pigment B. Evidence is presented that liver from congenitally jaundiced (Gunn) rats can metabolize small quantities of bilirubin to diazo-negative metabolites that were not characterized. This method is applicable to the quantities of enzyme derived from the small amounts of liver such as might be obtained in human liver biopsy samples.