[Changes in the liver transport of bile pigments in certain forms of jaundice under the influence of novobiocin and luminal].

The novobiocin and luminal test application increases the possibilities to differentiate premicrosome from postmicrosome jaundice and extends the knowledge on hyperbilirubinemia pathobiochemistry. Novobiocin (an antibiotic) inhibits the conjugation and glucuronidizing of bile pigments. Accordingly, the novobiocin test is strongly positive in any premicrosome jaundice form--Gilberts's disease, posthepatitis hyperbilirubinemia (PHHB) and hemolytic jaundice. It is negative in hepatocellular and hepatocanalicular jaundice, and in Dubin-Johnson's syndrome. In premicrosome jaundice with fluctuating bilirubinemia and normal bilirubin level at the time of examination, the novobiocin test may bring about manifestation of a latent or temporary compensated defect which proves to be most helpful in diagnosing. It is assumed that hemolytic jaundice is caused, apart from bile pigments hyperproduction, also by concomitant disorders in the intrahepatal transport of bile pigments. The latter hypothesis is corroborated by the data of the study. The luminal test is likewise markedly positive in premicrosome jaundice, and negative--in chronic hepatocellular and hepatocanalicular jaundice. In some instances with slight defect in the intrahepatal transport of pigments, the luminal test accounts for normalization of bilirubinemia and of the direct to total bilirubin ratio. The test is moderately positive in the syndrome of Dubin-Johnson. The latter fact supports the hypothesis that luminal, alongside the effect on transport mechanisms, exerts influence on bile pigments excretion also.