Proteins of guinea-pig bile: selective resorption in the gall bladder.

We have examined and compared the proteins present in guinea-pig bile as collected either from the common hepatic duct or from the gall bladder. Guinea-pig bile, collected from the common bile duct, has a rather low concentration of protein. Detailed examination shows that the concentrations of actively transported proteins such as immunoglobulin A and haptoglobin:haemoglobin complexes are markedly lower than in rats although the concentrations of proteins which, like albumin, leak non-specifically into bile are similar in the two species. We also find that the protein composition of guinea-pig bile is extensively and selectively modified by resorption of protein in the gall bladder.