Effect of Phalloidin on Biliary Lipid Secretion in Rats

1980 ◽  
Vol 58 (6) ◽  
pp. 545-548 ◽  
Author(s):  
Marta Dubin ◽  
S. Erlinger
Keyword(s):  
Bile Acid ◽  
Saturation Index ◽  
Circumstantial Evidence ◽  
Cholesterol Concentration ◽  
Biliary Lipid ◽  
Biliary Cholesterol ◽  
Lipid Secretion ◽  
Cholesterol Saturation ◽  
Cholesterol Saturation Index ◽  
Cholesterol Secretion

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.

Bile Lipid Secretion in Obese and Non-Obese Individuals with and without Gallstones

1985 ◽  
Vol 69 (1) ◽  
pp. 71-79 ◽  
Author(s):  
A. Reuben ◽  
P. N. Maton ◽  
G. M. Murphy ◽  
R. H. Dowling
Keyword(s):  
Bile Acid ◽  
Acid Secretion ◽  
Biliary Lipid ◽  
Biliary Cholesterol ◽  
Cholesterol Gallstones ◽  
Lipid Secretion ◽  
Biliary Cholesterol Secretion ◽  
Cholesterol Secretion ◽  
Bile Acid Secretion ◽  
Secretion Rates

1. Biliary lipid secretion rates were measured in non-obese and obese individuals with and without cholesterol gallstones, using a steady-state, amino acid duodenal perfusion method. In addition, biliary lipid secretion rates were measured in five obese gallstone patients receiving high-dose chenodeoxycholic acid therapy (16-22 mg day−1 kg−1). 2. Bile acid secretion rates in the non-obese patients with cholesterol gallstones (563+sem 70 μmol/h, n = 6) were significantly lower than in the non-obese controls (1078 + 210 μmol/h, n = 10, P < 0.05), whereas cholesterol secretion rates were similar in the non-obese individuals with and without gallstones (51+7 and 42+4 μmol/h respectively). 3. In the obese, both with and without gallstones, the major abnormality was hypersecretion of cholesterol (107+7 μmol/h, n = 7, and 81 + 15 μmol/h, n = 7, respectively). Both these values were significantly greater than those in the non-obese controls (P < 0.01-0.02). 4. Biliary cholesterol secretion rates correlated significantly with bile acid secretion rates but, for every mole of bile acid secreted, the obese secreted more cholesterol than the non-obese. 5. Chenodeoxycholic acid treatment lowered biliary cholesterol saturation in obese gallstone patients by reducing biliary cholesterol secretion. 6. These results suggest that there are two major types of defect in biliary lipid secretion in gallstone patients: reduced biliary bile acid secretion in non-obese gallstone patients and excessive biliary cholesterol secretion in the obese.

Differing effects of norcholate and cholate on bile flow and biliary lipid secretion in the rat

1984 ◽  
Vol 246 (1) ◽  
pp. G67-G71
Author(s):  
E. R. O'Maille ◽  
S. V. Kozmary ◽  
A. F. Hofmann ◽  
D. Gurantz
Keyword(s):  
Bile Acid ◽  
Acid Secretion ◽  
Bile Acids ◽  
Bile Flow ◽  
Critical Micellar Concentration ◽  
Biliary Lipid ◽  
Lipid Secretion ◽  
Unit Increase ◽  
Cholesterol Secretion ◽  
Bile Acid Secretion

The effects of norcholate (a C23 bile acid that differs from cholate in having a side chain containing four rather than five carbon atoms) on bile flow and biliary lipid secretion were compared with those of cholate, using the anesthetized rat with a bile fistula. Norcholate and cholate were infused intravenously over the range of 0.6-6.0 mumol X min-1 X kg-1. Both bile acids were quantitatively secreted into bile; norcholate was secreted predominantly in unconjugated form in contrast to cholate, which was secreted predominantly as its taurine or glycine conjugates. The increase in bile flow per unit increase in bile acid secretion induced by norcholate infusion [17 +/- 3.2 (SD) microliters/mumol, n = 8] was much greater than that induced by cholate infusion (8.6 +/- 0.9 microliters/mumol, n = 9) (P less than 0.001). Both bile acids induced phospholipid and cholesterol secretion. For an increase in bile acid secretion (above control values) of 1 mumol X min-1 X kg-1, the increases in phospholipid secretion [0.052 +/- 0.024 (SD) mumol X min-1 X kg-1, n = 9] and cholesterol secretion (0.0071 +/- 0.0033 mumol X min-1 X kg-1, n = 9) induced by norcholate infusion were much less than those induced by cholate infusion (0.197 +/- 0.05 mumol X min-1 X kg-1, n = 9, and 0.024 +/- 0.011 mumol X min-1 X kg-1, n = 9, respectively; P less than 0.001 for both phospholipid and cholesterol). The strikingly different effects of norcholate on bile flow and biliary lipid secretion were attributed mainly to its possessing a considerably higher critical micellar concentration than cholate.

Effect of primary bile acids on bile lipid secretion from perfused dog liver

1975 ◽  
Vol 229 (3) ◽  
pp. 714-720 ◽  
Author(s):  
NE Hoffman ◽  
DE Donald ◽  
AF Hosmann
Keyword(s):  
Bile Acid ◽  
Bile Acids ◽  
Liver Perfusion ◽  
Biliary Lipid ◽  
Hepatic Extraction ◽  
Perfusion Technique ◽  
Lipid Secretion ◽  
Cholesterol Secretion ◽  
Dog Liver ◽  
Bile Acid Secretion

An isolated canine liver perfusion technique featuring a second dog as the pump oxygenator was used to compare biliary lipid secretion during randomized, steady-state perfusions at two different rates of cholyl taurine or chenodeoxycholyl taurine infusions. The hepatic extraction of the trihydroxy-conjugated bile acid was considerably greater than that of the dihydroxy conjugate, possibly explained by ultrafiltration experiments which indicated that cholyl taurine was less protein bound than chenodeoxycholyl taurine. Both bile acids induced phospholipid and cholesterol secretion that was linearly proportional to bile acid secretion. However, each mole of secreted chenodeoxycholyl taurine induced a greater relative secretion of phospholipid and cholesterol than did that of cholyl taurine. Thus in the canine liver, the two primary bile acids are extracted at different rates and induce biliary secretion of different relative lipid composition.

Relationship between Hepatic Cholesterol Synthesis and Biliary Cholesterol Secretion in Man: Hepatic Cholesterol Synthesis is not a Major Regulator of Biliary Lipid Secretion

1982 ◽  
Vol 62 (5) ◽  
pp. 515-519 ◽  
Author(s):  
P. N. Maton ◽  
A. Reuben ◽  
R. H. Dowling
Keyword(s):  
Bile Acid ◽  
Cholesterol Synthesis ◽  
Acid Output ◽  
Hepatic Cholesterol ◽  
Biliary Cholesterol ◽  
Lipid Secretion ◽  
Hepatic Cholesterol Synthesis ◽  
Biliary Cholesterol Secretion ◽  
Cholesterol Secretion

1. To examine the role of newly synthesized cholesterol as a determinant of bile lipid secretion, both hepatic cholesterol synthesis (as judged by the activity of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, EC 1.1.1.34; HMGCoAR) and steady state biliary cholesterol output were measured in nine patients. 2. HMGCoAR levels varied four fold (9–40 pmol min−1 mg−1) and biliary cholesterol secretion 2–5-fold (0.60−1.15 μUmol h−1 kg−1) but there was no correlation between these two variables (r = 0.18; P>0.05) nor between biliary bile acid output and HMGCoAR activity (r = 0.34; P>0.05). 3. There was, however, a linear relationship between bile acid and phospholipid secretion (r = 0.77; P<0.001) and between bile acid and cholesterol secretion (r = 0.69; P<0.05). 4. These results suggest that HMGCoAR activity is not a major determinant of cholesterol secretion nor at these secretion rates is HMGCoAR activity related to bile acid return to the liver.

Mechanism of bile acid-induced biliary lipid secretion in the rat: effect of conjugated bilirubin

1993 ◽  
Vol 264 (3) ◽  
pp. G462-G469 ◽  
Author(s):  
H. J. Verkade ◽  
R. Havinga ◽  
A. Gerding ◽  
R. J. Vonk ◽  
F. Kuipers
Keyword(s):  
Bile Acid ◽  
Bile Acids ◽  
Genetic Defect ◽  
Specific Interaction ◽  
Biliary Secretion ◽  
Biliary Lipid ◽  
Bile Acid Concentration ◽  
Lipid Secretion ◽  
Cholesterol Secretion ◽  
Conjugated Bilirubin

We have compared the effects of bilirubin and bilirubin ditaurate (BDT) on biliary phospholipid and cholesterol secretion in unanesthetized normal Wistar (NW) and Groningen Yellow (GY) Wistar rats under various experimental conditions. GY rats express a genetic defect in biliary secretion, but not in hepatic uptake, of various organic anions. Under physiological conditions, NW and GY rats showed similar biliary secretion rates of bile acids and of bilirubin, despite the fact that bilirubin concentrations in GY plasma were 25 times as high and in GY livers three times as high as in NW plasma and livers, respectively. Secretion of cholesterol and phospholipids was not impaired in GY rats under these conditions. Biliary secretion of intravenously injected BDT (3 mumol/100 g body wt) was delayed in eight-day bile-diverted GY rats and showed lower peak values when compared with NW rats. The inhibitory effects of BDT on phospholipid and cholesterol secretion paralleled these differences, being delayed and much less pronounced in GY rats. No overshoot in phospholipid or cholesterol secretion was observed when bilirubin output returned to preinjection values. Stimulation of [14C]choline-labeled phospholipid secretion after a bolus injection of taurochenodeoxycholic acid (1 mumol/100 g body wt) closely followed biliary bile acid concentration. Similarly, inhibition of labeled phospholipid secretion by BDT closely paralleled the biliary bilirubin concentration. Gel filtration studies (Sepharose 4B-CL) under micelle-preserving conditions demonstrated a specific interaction of BDT with biliary bile acids. The presented data indicate that conjugated bilirubin does not inhibit biliary lipid secretion via interaction with bile acids inside the hepatocyte.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of dietary fat composition on biliary cholesterol saturation index in dogs

1993 ◽  
Vol 101 (1) ◽  
pp. 3-7 ◽  
Author(s):  
M. C. Ballesta ◽  
E. Martinez-victoria ◽  
M. Manas ◽  
I. Seiquer ◽  
J. R. Huertas ◽  
...  
Keyword(s):  
Dietary Fat ◽  
Saturation Index ◽  
Biliary Cholesterol ◽  
Cholesterol Saturation ◽  
Cholesterol Saturation Index ◽  
Fat Composition
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