The isolation and partial characterization of the principal biliary glycoprotein

Purification of blood-group substances in human hepatic bile (HHB) and immunological characterization of anti-HHB serum

Blood-group substances (BGS) in human hepatic bile (HHB) of blood type A were purified 3657-7314-fold by ethanol sedimentation and column chromatography with DEAE Sephadex A-50 and Concanavalin A Sepharose 4B. An anti-HHB serum was raised by immunizing rabbits with the purified BGS in the HHB. Cross-reactions of the native anti-HHB serum with such human materials as type A blood cell, plasma, seminal fluid and saliva were eliminated by stepwise sequential absorptions with type A red blood cells, type O seminal fluid and type AB plasma. Precipitin titers of the native anti-HHB serum were x 320 and x 80 and those of the absorbed anti-HHB serum x 80 and x 20 against the immunogen and HHB, respectively. Organ and species specificity of the absorbed anti-HHB serum was checked by counter immunoelectrophoresis. It reacted specifically only with the immunogen and HHBs of various ABO blood types. No reactions with animal gallbladder biles were observed. In practical examinations, the specific anti-HHB serum identified 15 out of 20 (75%) HHB samples and 41 out of 46 (89%) human faeces samples. No reactions with animal gallbladder biles and animal faeces were observed.

Chemotactic behavior of Campylobacter jejuni

The chemotactic behavior of Campylobacter jejuni was determined in the presence of different amino acids, carbohydrates, organic acids, and preparations and constituents of mucin and bile. L-Fucose was the only carbohydrate and L-aspartate, L-cysteine, L-glutamate, and L-serine were the only amino acids producing a chemotactic (positive) response. Several salts of organic acids, including pyruvate, succinate, fumarate, citrate, malate, and alpha-ketoglutarate, were also chemoattractants, as were bile (beef, chicken, and oxgall) and mucin (bovine gallbladder and hog gastric). Most constituents of bile tested individually were chemorepellents, but the mucin component was chemoattractant. The chemotactic behavior of C. jejuni toward L-fucose, a constituent of both bile and mucin, may be an important factor in the affinity of the organism for the gallbladder and intestinal tract.

Free fatty acids: a stimulus for mucin hypersecretion in cholesterol gallstone biles

The concentration of free fatty acids, phosphatidylcholine and lysophosphatidylcholine, and the fatty acid composition as well as the levels of the mucins, analyzed by an improved GLC method, were examined in ten biles from patients with cholesterol gallstones (pathological biles) and in ten control biles. In pathological biles the amounts of free fatty acids and phosphatidylcholine, were significantly higher (8.99 +/- 1.09) vs. 2.75 +/- 0.62 micrograms/mg) and lower (6.62 +/- 0.71 vs. 21.91 +/- 3.86 micrograms/mg), respectively, than in control biles, indicating that a relationship exists between the two lipid fractions. Lysophosphatidylcholine concentrations remained unchanged in the two groups (1.02 +/- 0.55 micrograms/mg in pathological biles vs. 1.32 +/- 0.57 micrograms/mg in control biles). The increased levels of free fatty acids were directly correlated (r = 0.73, P less than 0.05) with biliary hypersecretion of mucus glycoproteins. Acetylglucosamine and acetylgalactosamine were significantly higher in pathological biles than in control biles (1.91 +/- 0.67 vs. 0.60 +/- 0.13 microgram/mg). The nucleating potency of the increased amounts of mucins, coupled with lowered levels of phosphatidylcholine, might play a very important role in stone formation and precipitation.

Quantitative and qualitative comparison of gall bladder mucus glycoprotein from patients with and without gall stones

Human gall bladder mucus glycoprotein was isolated by Sepharose 4B gel filtration followed by caesium chloride density gradient ultracentrifugation from four groups: patients with cholesterol gall stones, patients with pigmented stones, patients with complete obstruction of the cystic duct and patients with no biliary tract abnormalities (controls). Mucus glycoprotein concentrations in cholesterol gall stone bile (203 micrograms/ml +/- 199 SD, n = 17), pigment gall stone bile (110 micrograms/ml +/- 77 SD, n = 6) and control gall bladder bile (96 micrograms/ml +/- 98 SD, n = 11) were not significantly different. While bile from patients with complete obstruction of the cystic duct contained significantly higher concentrations of mucus glycoprotein (6220 micrograms/ml +/- 4130, n = 4). In vitro cholesterol nucleation time was not correlated to gall bladder mucus glycoprotein concentrations. Qualitative analysis of the carbohydrate and amino acid composition showed a basic structure typical of mucus glycoproteins in general. It is unlikely that either quantitative or qualitative differences in mucus glycoproteins are responsible for the rapid in vitro nucleation time characteristic of cholesterol gall stone patients.

Biliary proteins

The study of biliary proteins has grown enormously in the last 10 years. Although much has been recently learned about the nature, origin and hepatobiliary transport of these proteins, little is known of their function in bile or their effect on its physical state. This review will focus on description of the proteins and mechanisms by which they are secreted into bile.

Synthesis of glycoproteins in the Golgi complex of the mouse gallbladder epithelium during fasting, refeeding, and gallstone formation. A light microscopic autoradiographic and quantitative electron microscopic study

The mouse gallbladder epithelium was studied with light microscopic autoradiography and quantitative electron microscopy during fasting, refeeding and experimental gallstone formation. To determine the intracellular pathway of glycoproteins, H3-galactose was injected at different time intervals into the mice. At 10, 25 and 40 min after an intraperitoneal injection the gallbladders were fixed and prepared for light microscopy. As early as 10 min after injection, label was observed in supranuclear cytoplasmic regions and at 25 min, an increased radioactivity was present throughout the apical cytoplasm. At 40 min, silver grains were mainly present at the cell surface. Autoradiographs processed 25 min after an intraperitoneal H3-galactose injection after fasting for 48 h showed decreased supranuclear and apical radioactivity. After refeeding (12 h) there was an enhanced activity in both these regions. Animals fed a lithogenic diet for one month showed a marked increase of radioactive label mainly in cells of crypts and invaginations of the mouse gallbaldder mucosa. Morphometric measurements of the Golgi apparatus revealed that deprivation of food significantly dimished the volume density of the Golgi apparatus. Refeeding the amimals restored the volume density values to normal levels, In the course of gallstone formation there was a further significant increase in the volume density of the Golgi complexes as compared to controls.