Transcytotic vesicular carriers for polymeric IgA receptors accumulate in rat hepatocytes after bile duct ligation

1991 ◽  
Vol 98 (2) ◽  
pp. 205-216 ◽  
Author(s):  
J.M. Larkin ◽  
G.E. Palade
Keyword(s):  
Bile Duct ◽  
Serum Proteins ◽  
Bile Duct Ligation ◽  
Rat Hepatocytes ◽  
Frozen Sections ◽  
Transmission Electron ◽  
Duct Ligation ◽  
Sds Page ◽  
Vesicular Carriers

In rat hepatocytes, transcytotic vesicular carriers transport the mature 120 × 10(3) Mr form of the polymeric IgA receptor (pIgA-R), with or without its ligand, pIgA, from the sinusoidal to the biliary plasmalemma, where the ectodomain of the receptor is cleaved to produce an 80 × 10(3) Mr fragment that is secreted into the bile. Here we show that cholestasis induced by bile duct ligation results in the accumulation of transcytotic carriers, identified by the 120 × 10(3) Mr pIgA-R and pIgA, in the pericanalicular cytoplasm of hepatocytes. To determine the extent of pIgA-R accumulation, hepatic total microsomes (TM) were prepared from control and cholestatic rats. Solubilized TM proteins were separated by SDS-PAGE and receptor forms were detected by immunoblotting and autoradiography. Quantitative densitometry of these autoradiograms showed that after duct ligation the 120 × 10(3) Mr receptor accumulated to a level approximately threefold higher than the control. Concomitantly, immunologically related, novel 124, 90 and 80 × 10(3) Mr proteins (cholestatic antigens) became detectable. Immunoblot analyses of biliary and serum proteins showed that cholestasis resulted in: (1) a marked decrease in the concentrations of the 80 × 10(3) Mr receptor and pIgA in the bile, whereas albumin concentrations remained at control levels; and (2) a marked increase in the concentration of the 80 × 10(3) Mr receptor in the serum. Positive sites for pIgA-R were localized to the pericanalicular cytoplasm of hepatocytes by indirect immunofluorescence on semithin frozen sections in cholestatic hepatocytes. The sites were more numerous and the positive signal stronger than in controls. One day post-ligation, pIgA-positive sites were located to the same pericanalicular cytoplasm of hepatocytes; by three days, however, most pIgA appeared in sinusoidal endothelia and Kupffer cells. To validate the vesicular character of the receptor-positive sites, sham-operated and cholestatic livers were processed for either transmission electron microscopy (TEM) or immunogold localization of receptors on thin frozen sections. TEM verified the accumulation of pericanalicular vesicles in cholestatic hepatocytes. Immunogold tests localized pIgA-R to pleiomorphic, pericanalicular vesicles, which were increased in number, size and concentration of antigenic sites in cholestatic hepatocytes. These findings indicate that bile duct ligation provides a method for manipulating the in vivo transcytotic pathway and for accumulating previously unstudied transcytotic carriers in hepatocytes.

Vitamin D inhibits development of liver fibrosis in an animal model but cannot ameliorate established cirrhosis

2015 ◽  
Vol 308 (2) ◽  
pp. G112-G120 ◽  
Author(s):  
Shirley Abramovitch ◽  
Efrat Sharvit ◽  
Yosef Weisman ◽  
Amir Bentov ◽  
Eli Brazowski ◽  
...  
Keyword(s):  
Vitamin D ◽  
Growth Factor ◽  
Bile Duct ◽  
Liver Fibrosis ◽  
Bile Duct Ligation ◽  
Active Form ◽  
Preventive Treatment ◽  
Antifibrotic Effect ◽  
Duct Ligation

1,25(OH)2D3, the active form of vitamin D, has an antiproliferative and antifibrotic effect on hepatic stellate cells. Our aim was to investigate the potential of 1,25(OH)2D3 to inhibit the development of liver fibrosis and to ameliorate established fibrosis in vivo. The antifibrotic effect of 1,25(OH)2D3 was investigated in a thioacetamide (TAA) model (as a preventive treatment and as a remedial treatment) and in a bile duct ligation model. In the preventive model, rats received simultaneously intraperitoneum injection of TAA and/or 1,25(OH)2D3 for 10 wk. In the remedial model, rats were treated with TAA for 10 wk and then received 1,25(OH)2D3 or saline for 8 wk. Fibrotic score was determined by Masson staining. Collagen I, α-smooth muscle actin (α-SMA), tissue inhibitor of metalloproteinase-1 (TIMP1), platelet-derived growth factor (PDGF), and transforming growth factor-β (TGF-β) expression were measured by Western blot analysis and real-time PCR. Hypercalemia was detected by chemistry measurements. Preventive treatment of 1,25(OH)2D3 significantly suppressed liver fibrosis both macroscopically and microscopically and significantly lowered the fibrotic score of the TAA + 1,25(OH)2D3 group compared with the TAA group. 1,25(OH)2D3 significantly inhibited expression of PDGF and TGF-β by ∼50% and suppressed the expression of collagen Iα1, TIMP1, and α-SMA by approximately three-, two-, and threefold, respectively. In contrast, 1,25(OH)2D3 was inefficient in amelioration of established liver fibrosis. Administration of 1,25(OH)2D3 to bile duct ligation rats led to a high mortality rate probably caused by hypercalcemia. We conclude that 1,25(OH)2D3 may be considered as a potential preventive treatment in an in vivo model but failed to ameliorate established cirrhosis.

Peripheral vascular neuroeffector mechanisms in experimental cholestasis

1993 ◽  
Vol 265 (3) ◽  
pp. G579-G586 ◽  
Author(s):  
G. Jacob ◽  
O. Said ◽  
J. Finberg ◽  
A. Bomzon
Keyword(s):  
Electrical Stimulation ◽  
Bile Duct ◽  
Vascular Reactivity ◽  
Bile Duct Ligation ◽  
Norepinephrine Uptake ◽  
Pithed Rats ◽  
Duct Ligation ◽  
Adrenoceptor Agonists

Jaundiced patients have systemic hypotension and are more susceptible to hemorrhagic shock than nonjaundiced individuals. We have hypothesized that the mechanism whereby these cardiovascular complications arise is linked to a disturbance of the vascular neuroeffector process in the cardiovascular system. With the use of 3-day bile duct-manipulated (sham-operated) and bile duct-ligated rats, we have evaluated alpha-adrenoceptor function and amine uptake using in vivo and in vitro techniques. Blunted pressor responsiveness to norepinephrine, electrical stimulation, and the alpha 1-adrenoceptor agonists, methoxamine and phenylephrine, was observed in the bile duct-ligated pithed rats. In contrast, normal responsiveness to BHT-933 and clonidine, the alpha 2-adrenoceptor agonists, was seen in these animals. The uptake 1 blocker, cocaine, caused potentiation of equal magnitudes of the pressor responsiveness to electrical stimulation and norepinephrine in the sham-operated and bile duct-ligated pithed rats. In aortic rings prepared from the bile duct-ligated rats, blunted in vitro vascular reactivity to norepinephrine and the same alpha 1-adrenoceptor agonists was seen. Bile duct ligation had no effect on norepinephrine uptake or its kinetics in stressed and unstressed arterial rings and portal veins. We have thus concluded that bile duct ligation induces a defect in the functional expression of cardiovascular alpha 1-adrenoceptors without any effects on the activity of alpha 2-adrenoceptors or norepinephrine uptake.

Differential alteration of cytochrome P450 isoenzymes in two experimental models of cirrhosis

2000 ◽  
Vol 78 (11) ◽  
pp. 912-919 ◽  
Author(s):  
Marie-Claude Bastien ◽  
François Leblond ◽  
Vincent Pichette ◽  
Jean-Pierre Villeneuve
Keyword(s):  
Cytochrome P450 ◽  
Carbon Tetrachloride ◽  
Bile Duct ◽  
Serum Albumin ◽  
Breath Test ◽  
Bile Duct Ligation ◽  
Biliary Cirrhosis ◽  
Breath Tests ◽  
Duct Ligation

Liver diseases are associated with a decrease in hepatic drug elimination, but there is evidence that cirrhosis does not result in uniform changes of cytochrome P450 (CYP) isoenzymes. The objective of this study was to determine the content and activity of four CYP isoenzymes in the bile duct ligation and carbon tetrachloride (CCl4)-induced models of cirrhosis. The hepatic content of CYP1A, CYP2C, CYP2E1, and CYP3A was measured by Western blot analysis. CYP activity in vivo was evaluated with breath tests using substrates specific for different isoenzymes: caffeine (CYP1A2), aminopyrine (CYP2C11), nitrosodimethylamine (CYP2E1), and erythromycin (CYP3A). Bile duct ligation resulted in biliary cirrhosis; CYP1A, CYP2C and CYP3A content was decreased and the caffeine, aminopyrine, and erythromycin breath tests were reduced whereas CYP2E1 content and the nitrosodimethylamine breath test were unchanged compared with controls. CCl4 treatment resulted in cirrhosis of varying severity as assessed from the decrease in liver weight and serum albumin. In rats with mild cirrhosis, CYP content was comparable with controls except for a decrease in CYP2C. The activity of CYPs was also unchanged except for an increase in CYP2E1 activity. In rats with more severe cirrhosis, the content of all four CYP isoenzymes and the caffeine, aminopyrine, and erythromycin breath tests were reduced whereas the nitrosodimethylamine breath test was unchanged. In both models of cirrhosis, there was a significant correlation between the breath tests results and the severity of cirrhosis as assessed from serum albumin levels. These results indicate that content and the catalytic activity of individual CYP enzymes are differentially altered by cirrhosis in the rat and also suggest that drug probes could be useful to assess hepatic functional reserve.Key words: breath test, cirrhosis, cytochrome P450, bile duct ligation, carbon tetrachloride.

scholarly journals Regulation of cholesterol and bile acid homoeostasis in bile-obstructed rats

1991 ◽  
Vol 280 (2) ◽  
pp. 373-377 ◽  
Author(s):  
S Dueland ◽  
J Reichen ◽  
G T Everson ◽  
R A Davis
Keyword(s):  
Bile Acid ◽  
Bile Duct ◽  
Liver Function ◽  
Urinary Excretion ◽  
Bile Acids ◽  
Bile Duct Ligation ◽  
Microsomal Cytochrome ◽  
Duct Ligation ◽  
Cytochrome P 450

We examined how total blockage of biliary excretion, the major pathway through which cholesterol and bile acids are removed from the body, affects liver function, cholesterol and bile acid metabolism and homoeostasis. After 4 weeks of bile-duct ligation, rats showed impaired liver function, as documented by elevations in serum bilirubin and alkaline phosphatase activity. Moreover, bile-duct ligation decreased by about 30% both the amount of microsomal cytochrome P-450 in the liver and the elimination of aminopyrine in vivo, a reliable index in vivo of microsomal mixed-function oxidase activity. Cholesterol and bile acid contents in livers of bile-duct-ligated rats were doubled compared with sham-operated controls. Despite the increase in the contents of cholesterol and bile acids in liver, activities of the respective rate-limiting enzymes, 3-hydroxy-3-methylglutaryl-CoA reductase and cholesterol 7 alpha-hydroxylase, were doubled. Serum concentrations of bile acids and free cholesterol increased 25- and 4-fold respectively. The large increase in serum bile acids was associated with a 380-fold increase in the urinary excretion of bile acids. Although there is a general decrease in cytochrome P-450 content and drug metabolism involving cytochrome P-450-containing hydroxylases, the activity of cholesterol 7 alpha-hydroxylase, also a cytochrome P-450-containing enzyme, is actually increased. These data show that complete obstruction of the bile duct results in the selective impairment of microsomal cytochrome P-450. Increased activity of 7 alpha-hydroxylase, bile acid synthesis and urinary excretion provides an alternative excretory pathway that helps to maintain cholesterol homoeostasis when the biliary excretory pathway is eliminated.

Bile canalicular barrier function and expression of tight-junctional molecules in rat hepatocytes during common bile duct ligation

2001 ◽  
Vol 307 (2) ◽  
pp. 181-189 ◽  
Author(s):  
Yasunari Takakuwa ◽  
Yasuo Kokai ◽  
Ken-ichi Sasaki ◽  
Hideki Chiba ◽  
Hirotoshi Tobioka ◽  
...  
Keyword(s):  
Bile Duct ◽  
Common Bile Duct ◽  
Barrier Function ◽  
Bile Duct Ligation ◽  
Rat Hepatocytes ◽  
Common Bile Duct Ligation ◽  
Duct Ligation

M1567 CpG Motifs Induce Proinflammatory Events in Hepatic Stellate Cells and Are Involved in Bile Duct Ligation-Induced Hepatic Fibrosis In Vivo

2008 ◽  
Vol 134 (4) ◽  
pp. A-795
Author(s):  
Erwin Gäbele ◽  
Matthias Froh ◽  
Reiner Wiest ◽  
Florian Obermeier ◽  
Jürgen Schölmerich ◽  
...  
Keyword(s):  
Bile Duct ◽  
Hepatic Fibrosis ◽  
Hepatic Stellate Cells ◽  
Bile Duct Ligation ◽  
Stellate Cells ◽  
Cpg Motifs ◽  
Duct Ligation

Coexpression of periportal and perivenous enzymes in rat hepatocytes after experimental bile duct ligation: Comparison with intrasplenically transplanted hepatocytes

1996 ◽  
Vol 105 (4) ◽  
pp. 319-329 ◽  
Author(s):  
Lorraine Racine-Samson ◽  
Jean-Yves Scoazec ◽  
Alain Moreau ◽  
Laurence Christa ◽  
Dominique Bernuau ◽  
...  
Keyword(s):  
Bile Duct ◽  
Bile Duct Ligation ◽  
Rat Hepatocytes ◽  
Duct Ligation

scholarly journals In vivo dynamic metabolic imaging of obstructive cholestasis in mice

2009 ◽  
Vol 296 (5) ◽  
pp. G1091-G1097 ◽  
Author(s):  
Feng-Chieh Li ◽  
Yuan Liu ◽  
Guan-Tarn Huang ◽  
Ling-Ling Chiou ◽  
Jhih-Huei Liang ◽  
...  
Keyword(s):  
Bile Duct ◽  
Bile Duct Ligation ◽  
Imaging System ◽  
Multiphoton Microscopy ◽  
Metabolic Imaging ◽  
Bile Canaliculi ◽  
Duct Ligation ◽  
Obstructive Cholestasis ◽  
Rhodamine B Isothiocyanate

We tried to image obstructive cholestasis by using a newly developed imaging system to measure the alterations of hepatobiliary function in living mice with their bile ducts ligated. A hepatic imaging window was installed on the upper abdomen soon after the mice underwent ligation of the common bile duct. On the next day, the mice received intravenous injection of rhodamine B isothiocyanate-dextran and carboxyfluorescein diacetate. The later would be transformed into fluorogenic carboxyfluorescein (detected at ∼500–550 nm) by hepatocytes and then excreted into bile canaliculi. The images were acquired by multiphoton microscopy. The fluorescence intensities at ∼500–550 nm within hepatocytes or sinusoids were measured in time series. In mice with bile duct ligation, bile canaliculi failed to appear during the whole observation period over 100 min following carboxyfluorescein diacetate injection, whereas the fluorescence was retained much longer within sinusoids. Furthermore, the fluorescence intensities in sinusoids were persistently higher than in hepatocytes during the course. Bile duct ligation impedes hepatocytes to excrete carboxyfluorescein into bile canaliculi. The kinetics of fluorescence intensities in hepatocytes and sinusoids indicated there is an active machinery operating backflow of this fluorogenic bile solute from hepatocytes into sinusoids in the liver with obstructive cholestasis.

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