Cyclosporin A reduces canalicular membrane fluidity and regulates transporter function in rats

2001 ◽  
Vol 354 (3) ◽  
pp. 591-596 ◽  
Author(s):  
Shigeyuki YASUMIBA ◽  
Susumu TAZUMA ◽  
Hidenori OCHI ◽  
Kazuaki CHAYAMA ◽  
Goro KAJIYAMA
Keyword(s):  
Cyclosporin A ◽  
Membrane Fluidity ◽  
Membrane Vesicle ◽  
Sodium Taurocholate ◽  
Molar Ratio ◽  
Biliary Lipid ◽  
Membrane Phospholipids ◽  
Lipid Secretion ◽  
Canalicular Membrane ◽  
Transporter Expression

Changes of the biliary canalicular membrane lipid content can affect membrane fluidity and biliary lipid secretion in rats. The immunosuppressant cyclosporin A is known to cause intrahepatic cholestasis. This study investigated whether cyclosporin A influenced canalicular membrane fluidity by altering membrane phospholipids or transporter expression. In male Sprague–Dawley rats, a bile-duct cannula was inserted to collect bile, and sodium taurocholate was infused (100nmol/min per 100g) for 60min. During steady-state taurocholate infusion, cyclosporin A (20mg/kg) or vehicle was injected intravenously and then bile was collected for 80min. After killing the rats, canalicular membrane vesicles were prepared. Expression of canalicular membrane transporters was assessed by Western blotting and canalicular membrane vesicle fluidity was estimated by fluorescence polarization. Cyclosporin A reduced biliary lipid secretion along with a disproportionate reduction of lipids relative to bile acids. Cyclosporin A significantly decreased canalicular membrane fluidity along with an increase of the cholesterol/phospholipid molar ratio. Only expression of the transporter P-glycoprotein was increased by cyclosporin A. Because canalicular membrane transporter expression was largely unchanged by cyclosporin A despite a marked decrease of biliary lipid secretion, transporter activity may partly depend upon canalicular membrane fluidity.

Bile-salt hydrophobicity is a key factor regulating rat liver plasma-membrane communication: relation to bilayer structure, fluidity and transporter expression and function

2001 ◽  
Vol 359 (3) ◽  
pp. 605-610 ◽  
Author(s):  
Yasumasa ASAMOTO ◽  
Susumu TAZUMA ◽  
Hidenori OCHI ◽  
Kazuaki CHAYAMA ◽  
Hiroshi SUZUKI
Keyword(s):  
Body Weight ◽  
Plasma Membrane ◽  
Bile Salt ◽  
Membrane Fluidity ◽  
Bile Salts ◽  
Membrane Phospholipids ◽  
Canalicular Membrane ◽  
Liver Plasma Membrane ◽  
And Function ◽  
Transporter Expression

Bile-salt hydrophobicity regulates biliary phospholipid secretion and subselection. The aim of this study was to determine whether bile salts can influence liver plasma membrane phospholipids and fluidity in relation to the ATP-dependent transporter. Rats were depleted of bile salts by overnight biliary diversion and then sodium taurocholate was infused intravenously at a constant rate (200nmol/min per 100g of body weight), followed by infusion of bile salts with various hydrophobicities (taurochenodeoxycholate, tauroursodeoxycholate, tauro-β-muricholate, tauro-α-muricholate at 200nmol/min per 100g of body weight). The hydrophobicity of the infused bile salts correlated with that of biliary phospholipids, but was inversely related to that of the canalicular membrane bilayer. Canalicular membrane fluidity (estimated by 1,6-diphenyl-1,3,5-hexatriene fluorescence depolarization) and expression of multidrug-resistance proteins (Mrp2, Mrp3) and apical Na+-dependent bile-salt transporter (ASBT) were increased by hydrophilic bile salts, although there was no marked change in the expression of P-glycoprotein subfamilies (Mdr2). Bile-salt export pump (Bsep) expression was increased along with increasing bile-salt hydrophobicity. Bile salts modulate canalicular membrane phospholipids and membrane fluidity, as well as the ATP-dependent transporter expression and function, and these actions are associated with their hydrophobicity. The cytoprotective effect of hydrophilic bile salts seems to be associated with induction of Mrp2, Mrp3 and ASBT.

Effect of glycodihydrofuisidate on sulfobromophthalein transport maximum in the hamster

1976 ◽  
Vol 231 (6) ◽  
pp. 1875-1878 ◽  
Author(s):  
Y Delage ◽  
M Dumont ◽  
S Erlinger
Keyword(s):  
Bile Salt ◽  
Transport System ◽  
Bile Salts ◽  
Sodium Taurocholate ◽  
Specific Effect ◽  
Biliary Secretion ◽  
Biliary Lipid ◽  
Lipid Secretion ◽  
Dye Transport ◽  
Cholesterol Secretion

The effect on sulfobromophathalein transport maximum (Tm) and biliary lipid secretion of sodium glyco-24,25-dihydrofusicate, a micelle-forming compound secreted into bile, has been studied in the hamster and compared to that of a physiological bile salt, sodium taurocholate. Biliary phospholipid and cholesterol secretion increased both during glycodihydrofusidate and taurocholate administration, an observation which suggest that both compounds increased th biliary secretion of micelle-forming compounds. In contrast, only taurocholate increased sulfobromophthalein Tm into bile, while glycodihydrofusidate administration decreased it. This observation suggests that the increase in sulfobromophthalein Tm observed during taurocholate administration is not the result of micellar sequestration. It could rather be the consequence of a specific effect of bile salts on the dye transport system.

scholarly journals Control of biliary phospholipid secretion. Effect of continuous and discontinuous infusion of taurocholate on biliary phospholipid secretion

1986 ◽  
Vol 234 (2) ◽  
pp. 421-427 ◽  
Author(s):  
K Rahman ◽  
T G Hammond ◽  
P J Lowe ◽  
S G Barnwell ◽  
B Clark ◽  
...  
Keyword(s):  
Animal Model ◽  
Bile Salt ◽  
Biliary Fistula ◽  
Perfused Liver ◽  
Biliary Lipid ◽  
Short Pulses ◽  
Lipid Secretion ◽  
Canalicular Membrane ◽  
Infusion Period ◽  
Salt Secretion

A major determinant of biliary lipid secretion is bile-salt secretion. Taurocholate (TC), a micelle-forming bile salt, was infused continuously at different rates in both isolated perfused livers and biliary-fistula rats. In both of these systems, infusion of TC brought about an elevated secretion of phosphatidylcholine for the duration of the TC infusion period. Initial phospholipid/bile-salt ratios in the bile were higher in the whole-animal model than in isolated livers, but at the higher infusion rates both secreted approx. 6 mol of phospholipid for every 100 mol of bile salt. The secretion of phospholipid, which was maintained even at high rates of bile-salt infusion, suggest a continuous and regulated phospholipid supply and secretion mechanism. In contrast, however, multiple short pulses of TC to the perfused liver, which brought about relatively equal biliary bile-salt output pulses, did not bring about equal phospholipid outputs, since the phospholipid peak size declined with each bile-salt pulse. These experiments taken together suggest either that a threshold (intracellular) bile-salt concentration may be required to ‘switch-on’ the phospholipid supply and that it may need to be maintained for continuous biliary phospholipid supply to the canalicular membrane.

scholarly journals Partial characterization of mechanism(s) by which sulphobromophthalein reduces biliary lipid secretion

1993 ◽  
Vol 291 (1) ◽  
pp. 173-177 ◽  
Author(s):  
G Yamashita ◽  
S Tazuma ◽  
K Horikawa ◽  
N Aihara ◽  
H Ochi ◽  
...  
Keyword(s):  
Bile Salt ◽  
Sodium Taurocholate ◽  
Bile Canaliculus ◽  
Biliary Secretion ◽  
Dependent Manner ◽  
Biliary Lipid ◽  
Sprague Dawley ◽  
Lipid Secretion ◽  
Biliary Lipids ◽  
Sprague Dawley Rats

This study was performed to explore the mechanisms by which sulphobromophthalein (BSP) reduces the secretion of biliary lipid using Sprague-Dawley rats (SDR) and mutant rats with congenital conjugated hyperbilirubinaemia bred from SDR (EHBR). We infused the bile-salt-pool-depleted rats with sodium taurocholate at a constant rate of 160 nmol/min per 100 g body wt. with BSP (12.5, 25 and 50 nmol/min per 100 g body wt.) or BSP-GSH (12.5, 25 and 50 nmol/min per 100 g body wt.). The biliary secretion of BSP and BSP-GSH was markedly impaired in EHBR as compared with that in SDR. BSP reduced the biliary secretion of cholesterol and phospholipids in a dose-dependent manner without affecting the secretion of bile salts and composition of fatty acids in phospholipids in SDR, but had no effect on lipid secretion in EHBR. In contrast, BSP-GSH had no such effect on biliary lipids, either in the SDR or EHBR. In addition, the amount of BSP in the liver of EHBR was in the same range as that of SDR. Therefore it is unlikely that an intracellular mechanism is involved in the phenomenon of uncoupling by BSP. We conclude that the uncoupling of biliary lipids from bile-salt secretion by BSP occurs at the level of the bile canaliculus following the secretion of unconjugated BSP.

scholarly journals Cyclosporin A reduces canalicular membrane fluidity and regulates transporter function in rats

2001 ◽  
Vol 354 (3) ◽  
pp. 591 ◽  
Author(s):  
Shigeyuki YASUMIBA ◽  
Susumu TAZUMA ◽  
Hidenori OCHI ◽  
Kazuaki CHAYAMA ◽  
Goro KAJIYAMA
Keyword(s):  
Cyclosporin A ◽  
Membrane Fluidity ◽  
Canalicular Membrane

scholarly journals Effects of organic anions on biliary lipid secretion in rats. Importance of association with biliary lipid structures

1992 ◽  
Vol 286 (1) ◽  
pp. 193-196 ◽  
Author(s):  
G Yamashita ◽  
S Tazuma ◽  
G Kajiyama
Keyword(s):  
Bile Salt ◽  
Organic Anion ◽  
Sodium Taurocholate ◽  
Organic Anions ◽  
Phenol Red ◽  
Dependent Manner ◽  
Biliary Lipid ◽  
Lipid Secretion ◽  
Biliary Lipids ◽  
Salt Secretion

This study was performed to determine the effects of various organic anions on biliary lipid secretion in rats. We infused bile-salt-pool-depleted rats with sodium taurocholate at a constant rate, with or without various organic anions: Indocyanine Green (ICG), bromosulphophthalein (BSP), BSP-glutathione and Phenol Red (PR). BSP decreased biliary secretion of cholesterol and phospholipids in a dose-dependent manner without affecting bile salt secretion (uncoupling), and this change was fully reversible. In contrast, ICG, BSP-glutathione and PR did not cause such an uncoupling of biliary lipids. In addition, the distribution pattern of each organic anion to various lipid particles was determined by gel-permeation chromatography. BSP was predominantly associated with bile salt micelles, whereas vesicular association was dominant for ICG, and both BSP-glutathione and PR formed only self-aggregations. From these data, we concluded that the uncoupling of biliary lipids from bile salt secretion by BSP resulted from the interaction between BSP and bile salt micelles in the bile canaliculus, and that this interaction inhibited the capacity of bile salts to induce the secretion of phospholipids and cholesterol.

scholarly journals Imaging biliary lipid secretion in the rat: ultrastructural evidence for vesiculation of the hepatocyte canalicular membrane.

1996 ◽  
Vol 36 (10) ◽  
pp. 2147-2163 ◽  
Author(s):  
J M Crawford ◽  
G M Möckel ◽  
A R Crawford ◽  
S J Hagen ◽  
V C Hatch ◽  
...  
Keyword(s):  
Biliary Lipid ◽  
Lipid Secretion ◽  
Canalicular Membrane ◽  
Ultrastructural Evidence
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