1. The biliary maximum secretory rate (SR max. ) of glycoursodeoxycholate in the bile fistula anaesthetized rat was about five times that of unconjugated ursodeoxycholate. 2. Likewise, the biliary SR max. of tauro-7-ketolithocholate was more than three times that of unconjugated 7-ketolithocholate. The SR max. of 7-ketolithocholate infused with taurine (to avoid depletion of the taurine pool) was still significantly lower than that of exogenous tauro-7-ketolithocholate. 3. These data support the hypothesis that, for bile acids that are poorly water soluble, the maximal biliary secretion rate is dependent on conjugating capacity, which is the limiting step in the overall transport from plasma into bile.
1. The effect of phalloidin on bile acid, phospholipid and cholesterol secretion into bile was studied in rats with bile fistulae. 2. Phalloidin, when given for 7 days, induced a significant decrease in biliary cholesterol concentration and cholesterol saturation index. Bile acid and phospholipid concentration in bile remained unchanged. This effect was less marked in animals receiving the drug for 3 days, and not detectable in animals treated for 1 day. 3. These results provide circumstantial evidence for the hypothesis that microfilament dysfunction may lead to alterations in cholesterol secretion into bile.
1. The influence of lysine acetylsalicylate on bile flow, erythritol clearance and bile salt, phospholipid and cholesterol secretion in bile was studied in unanaesthetized dogs fitted with a Thomas duodenal cannula. 2. Lysine acetylsalicylate induced a marked increase in bile flow and a parallel increase in erythritol clearance although the bile salt secretion remained unchanged; this suggests that the compound stimulated the formation of the canalicular (hepatocytic) bile salt-independent fraction of bile flow. 3. Lysine acetylsalicylate induced a significant decrease in biliary phospholipid and cholesterol secretion and the cholesterol saturation of bile was significantly reduced. 4. It is postulated that the decrease in phospholipid and cholesterol secretion resulted from the dilution of intracanalicular bile salts. This effect of lysine acetylsalicylate, and possibly of other bile salt-independent choleretics, may be of value in the treatment of cholesterol gallstones in man.