Bile protein secretion in the rat stimulated by taurocholate effect of chloroquine

1988 ◽  
Vol 66 (6) ◽  
pp. 749-753 ◽  
Author(s):  
R. A. Marinelli ◽  
C. E. Carnovale ◽  
E. A. Rodríguez Garay
Keyword(s):  
Acid Phosphatase ◽  
Molecular Mass ◽  
Protein Secretion ◽  
Biliary Excretion ◽  
Sodium Taurocholate ◽  
Protein Excretion ◽  
Chloroquine Treatment ◽  
Lysosomotropic Agent ◽  
The Individual ◽  
Bile Protein

The biliary protein excretion during sodium taurocholate induced choleresis was studied in normal rats and in rats treated with the lysosomotropic agent, chloroquine. The analysis of the protein component in bile was made on SDS–polyacrilamide gel, and the individual polypeptides were quantitated by densitometry. The excretion of bile polypeptides was compared with that of lysosomal acid phosphatase. The biliary excretion of polypeptides of molecular mass lower than and equal to 54 kDa was markedly stimulated by taurocholate-induced choleresis. Chloroquine treatment of rats diminished the biliary excretion of such polypeptides and also inhibited their excretion induced by taurocholate. The behaviour of these polypeptides was well correlated to that of the lysosomal marker. The biliary excretion of polypeptide bands of a higher molecular mass (up to 140 kDa) did not show major changes during taurocholate-induced choleresis in any of the groups. The results indicate that biliary excretion of proteins in the rat may be either stimulated by taurocholate or may be independent of the bile salt. The former requires the functional integrity of chloroquine-sensitive hepatocyte compartments, which may involve the lysosomes.

Biliary excretion of proteins in the rat during dehydrocholate choleresis

1990 ◽  
Vol 68 (9) ◽  
pp. 1286-1291 ◽  
Author(s):  
Raúl A. Marinelli ◽  
Cristina E. Carnovale ◽  
Emilio A. Rodríguez Garay
Keyword(s):  
Acid Phosphatase ◽  
Bile Salt ◽  
Molecular Mass ◽  
Biliary Excretion ◽  
High Molecular Mass ◽  
Subsequent Increase ◽  
Microtubule Inhibitors ◽  
Protein Excretion ◽  
The Individual

Choleresis induced by dehydrocholate (DHC) stimulates the discharge into bile of lysosomes, which are implicated in the biliary excretion of proteins. Contrary to taurocholate-induced choleresis, DHC choleresis is not affected by microtubule (mt) inhibition. Therefore, the role of mt's in the biliary protein excretion during bile salt choleresis was analyzed in this study. Normal rats and rats treated with the mt poisons colchicine or vinblastine or with the acidotropic agent chloroquine (Cq) were used. The analysis of the protein component in bile was made on SDS–polyacrylamide gel, and the individual polypeptides were quantitated by densitometry. The excretion of bile polypeptides was compared with that of lysosomal acid phosphatase. Bile flow and bile salt output did not show changes on account of treatments. The biliary excretion of acid phosphatase was stimulated by DHC, and it was not affected by mt inhibitors but was markedly diminished by Cq. DHC choleresis produced different effects on the bile polypeptides. The biliary excretion of polypeptides of high molecular mass (84–140 kDa) was stimulated by DHC. Cq treatment increased their basal biliary excretions, whereas DHC-induced secretion was qualitatively and quantitatively similar to that of controls. The 69-kDa polypeptide (albumin) also increased during DHC-induced choleresis, but it showed a different excretory pattern. Cq treatment inhibited such an increase but no correlation with the excretory pattern of the lysosomal marker was found. The biliary excretion of polypeptides of low molecular mass (down to 14 kDa) suffered a transitory decrease and then a subsequent increase over basal values during the DHC choleresis. Cq treatment diminished their biliary excretions during basal and DHC-induced choleresis. Treatment with the mt inhibitors markedly diminished the biliary excretions of all polypeptides. The results indicate that DHC-induced choleresis influenced the biliary protein excretion in a way different to that induced by taurocholate. Thus, the biliary excretion of proteins that did not require lysosomes to reach the bile was stimulated, while that requiring such organelles was transiently diminished. In addition, the biliary excretion of proteins was dependent on mt's excepting those of lysosomal source.Key words: dehydrocholate choleresis, biliary proteins, microtubule inhibitors, chloroquine.

scholarly journals [Phosphotyrosine]protein phosphatase in rat brain. A major [phosphotyrosine]protein phosphatase is a 23 kDa protein distinct from acid phosphatase

1986 ◽  
Vol 239 (1) ◽  
pp. 155-162 ◽  
Author(s):  
M Okada ◽  
K Owada ◽  
H Nakagawa
Keyword(s):  
Acid Phosphatase ◽  
Molecular Mass ◽  
Rat Brain ◽  
Column Chromatography ◽  
Protein Phosphatase ◽  
Specific Activity ◽  
Deae Cellulose ◽  
Sodium Vanadate ◽  
Nitrophenyl Phosphate ◽  
Phosphotyrosine Protein Phosphatase

A [phosphotyrosine]protein phosphatase (PTPPase) was purified almost to homogeneity from rat brain, with [32P]p130gag-fps, an oncogene product of Fujinami sarcoma virus, as substrate. The characteristics of the purified preparation of PTPPase were as follows: the enzyme was a monomer with a molecular mass of 23 kDa; its optimum pH was 5.0-5.5; its activity was not dependent on bivalent cations; its activity was strongly inhibited by sodium vanadate, but was not inhibited by ZnCl2, L(+)-tartrate or NaF; it catalysed the dephosphorylation of [32P]p130gag-fps, [[32P]Tyr]casein, p-nitrophenyl phosphate and L-phosphotyrosine, but did not hydrolyse [[32P]Ser]tubulin, L-phosphoserine, DL-phosphothreonine, 5′-AMP, 2′-AMP or beta-glycerophosphate significantly. During the purification, most of the PTPPase activity was recovered in distinct fractions from those of conventional low-molecular-mass acid phosphatase (APase), which was reported to be a major PTPPase [Chernoff & Li (1985) Arch. Biochem. Biophys. 240, 135-145], from DE-52 DEAE-cellulose column chromatography, and those two enzymes could be completely separated by Sephadex G-75 column chromatography. APase also showed PTPPase activity with [32P]p130gag-fps, but the specific activity was lower than that of PTPPase with molecular mass of 23 kDa, and it was not sensitive to sodium vanadate. These findings suggested that PTPPase (23 kDa) was the major and specific PTPPase in the cell.

In vitro translation of human prostatic acid phosphatase mRNA and processing of the translation products by microsomal membranes and endoglycosidase H

1987 ◽  
Vol 65 (10) ◽  
pp. 921-924 ◽  
Author(s):  
Gilles Paradis ◽  
Jean Y. Dubé ◽  
Pierre Chapdelaine ◽  
Roland R. Tremblay
Keyword(s):  
Acid Phosphatase ◽  
Molecular Mass ◽  
Polyacrylamide Gel Electrophoresis ◽  
Prostatic Acid Phosphatase ◽  
In Vitro Translation ◽  
Acid Phosphatases ◽  
Major Band ◽  
Microsomal Membranes ◽  
Endoglycosidase H

Poly(A)+ RNA was isolated from human prostatic tissue and translated in vitro in a rabbit reticulocyte lysate translation assay. Acid phosphatase labeled with [35S]methionine was immunoprecipitated with an antibody against seminal plasma acid phosphatase. Two-dimensional polyacrylamide gel electrophoresis of the immunoprecipitate, followed by fluorography, revealed the presence of two spots (one major and one minor), both having a molecular mass of 43 kilodaltons (kDa) and an isoelectric point higher than mature acid phosphatase. Addition of canine pancreatic membranes to the translation assay resulted in the formation of four immunoprecipitable spots with molecular masses ranging from 43 to 49 kDa on one-dimensional gels. These spots probably represent acid phosphatases containing one to four core sugar groups, since after the addition of endoglycosidase H the molecular mass heterogeneity was abolished and we observed only one major band with a molecular mass (41 kDa) slightly lower than the ones of the primary translation product. These results suggest that human prostatic acid phosphatases are synthesized as two 43-kDa preproteins, which are further processed to 41-kDa proteins by removal of their signal peptide. Heterogeneity of the native protein arises mostly from glycosylation at four sites and not from differences in the amino acid sequence of the various forms.

Glucagon induces biliary protein excretion in guinea pigs

1993 ◽  
Vol 264 (5) ◽  
pp. G961-G966
Author(s):  
R. Lenzen ◽  
N. Tavoloni
Keyword(s):  
Biliary Excretion ◽  
Guinea Pigs ◽  
Lysosomal Enzymes ◽  
Fluid Transport ◽  
Dependent Manner ◽  
Canalicular Membrane ◽  
Protein Excretion ◽  
Endogenous Protein ◽  
Camp System ◽  
Protein Output

This study was done to determine glucagon's effect on protein biliary excretion in anesthetized, bile duct-cannulated guinea pigs. Glucagon (1.4 nmol.min-1.kg-1) induced choleresis and increased protein biliary concentration from 0.12 +/- 0.04 to 0.20 +/- 0.6 mg/ml and protein output from 22.8 +/- 3.8 to 54.5 +/- 16.1 micrograms.kg-1.min-1. Protein biliary excretion increased during the first 10 min of glucagon infusion and progressively declined thereafter. Biochemical analysis of biliary protein revealed that the increase could be accounted for primarily by an increase in the lysosomal enzymes acid phosphatase and beta-glucuronidase. Biliary excretion of the canalicular membrane enzymes 5'-nucleotidase and alkaline phosphatase only modestly increased, whereas that of [14C]sucrose, a marker of paracellular fluid transport, was unaffected. On the other hand, glucagon enhanced biliary entry of horseradish peroxidase in a fashion similar to that observed with total endogenous protein. These effects were mediated by the adenosine 3',5'-cyclic monophosphate (cAMP) system, since infusion of dibutyryl-cAMP at 0.5 mumol.kg-1.min-1 increased bile flow and biliary protein excretion in a time-dependent manner, as observed with glucagon. Glucagon's failure to sustain enhanced protein biliary output was not due to declining hepatic concentrations of cAMP or to depletion of hepatocellular lysosomal enzymes. These studies provide evidence that glucagon stimulates biliary excretion of protein in guinea pigs that can be accounted for by biliary discharge of enzyme originating from the canalicular membrane and, primarily, from the lysosomal compartment. Although the precise mechanism(s) underlying these effects remains to be elucidated, it is suggested that the increase in canalicular membrane enzyme excretion is due to glucagon's effect on exocytosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Tauroursodeoxycholate prevents biliary protein excretion induced by other bile salts in the rat

1985 ◽  
Vol 248 (4) ◽  
pp. G407-G417 ◽  
Author(s):  
K. Kitani ◽  
M. Ohta ◽  
S. Kanai
Keyword(s):  
Alkaline Phosphatase ◽  
Lactate Dehydrogenase ◽  
Biliary Excretion ◽  
Bile Salts ◽  
Cytotoxic Effects ◽  
Pentobarbital Sodium ◽  
Protein Excretion ◽  
Anesthetized Rats ◽  
Preventive Effects

Biliary excretion of various proteins (5'-nucleotidase, alkaline phosphatase, lactate dehydrogenase, and albumin) was investigated in pentobarbital sodium-anesthetized rats infused with different bile salts [taurocholate (TC), taurochenodeoxycholate (TCDC), and tauroursodeoxycholate (TUDC)]. A TCDC infusion at 0.4 mumol . min-1 . 100 g body wt-1 caused much higher increases in the biliary excretion of these proteins compared with the respective values in rats that received an infusion of TC at a threefold higher rate (1.2 mumol . min-1 . 100 g body wt-1). In contrast, a TUDC infusion at 1.8 mumol . min-1 . 100 g body wt-1 showed the minimum effect on these protein leakages. A combined infusion of TCDC (0.4 mumol . min-1 . 100 g-1) and TUDC (0.6 mumol . min-1 . 100 g-1) resulted in drastic (8- to 20-fold) decreases in excretion of these enzymes and albumin compared with respective values in rats infused with TCDC alone. Similar preventive effects were observed with the addition of TUDC to the infusion of TC (1.2 mumol . min-1 . 100 g-1). These results suggest that the hepatic cytotoxic effects of TC and TCDC can be prevented by the simultaneous infusion of TUDC in rats.

scholarly journals Comparative studies of rat recombinant purple acid phosphatase and bone tartrate-resistant acid phosphatase

1997 ◽  
Vol 321 (2) ◽  
pp. 305-311 ◽  
Author(s):  
Barbro EK-RYLANDER ◽  
Tomas BARKHEM ◽  
Jenny LJUSBERG ◽  
Lars ÖHMAN ◽  
K. Kristoffer ANDERSSON ◽  
...  
Keyword(s):  
Acid Phosphatase ◽  
Molecular Mass ◽  
Comparative Studies ◽  
Expression System ◽  
Recombinant Enzyme ◽  
Purple Acid Phosphatase ◽  
Tartrate Resistant Acid Phosphatase ◽  
Single Chain ◽  
Purple Colour ◽  
Rat Bone

The tartrate-resistant acid phosphatase (TRAP) of rat osteoclasts has been shown to exhibit high (85Ő94%) identity at the amino acid sequence level with the purple acid phosphatase (PAP) from bovine spleen and with pig uteroferrin. These iron-containing purple enzymes contain a binuclear iron centre, with a tyrosinate-to-Fe(III) charge-transfer transition responsible for the purple colour. In the present study, production of rat osteoclast TRAP could be achieved at a level of 4.3 mg/litre of medium using a baculovirus expression system. The enzyme was purified to apparent homogeneity using a combination of cation-exchange, hydrophobic-interaction, lectin-affinity and gel-permeation chromatography steps. The protein as isolated had a purple colour, a specific activity of 428 units/mg of protein and consisted of the single-chain form of molecular mass 34 kDa, with only trace amounts of proteolytically derived subunits. The recombinant enzyme had the ability to dephosphorylate bone matrix phosphoproteins, as previously shown for bone TRAP. Light absorption spectroscopy of the isolated purple enzyme showed a λmax at 544 nm, which upon reduction with ascorbic acid changed to 515 nm, concomitant with the transition to a pink colour. EPR spectroscopic analysis of the reduced enzyme at 3.6 K revealed a typical Ɓ-hydr(oxo)-bridged mixed-valent Fe(II)Fe(III) signal with g-values at 1.96, 1.74 and 1.60, proving that recombinant rat TRAP belongs to the family of PAPs. To validate the use of recombinant PAP in substituting for the rat bone counterpart in functional studies, various comparative studies were carried out. The enzyme isolated from bone exhibited a lower Km for p-nitrophenyl phosphate and was slightly more sensitive to PAP inhibitors such as molybdate, tungstate, arsenate and phosphate. In contrast with the recombinant enzyme, TRAP from bone was isolated predominantly as the proteolytically cleaved, two-subunit, form. Both the recombinant enzyme and rat bone TRAP were shown to be substituted with N-linked oligosaccharides. A slightly higher apparent molecular mass of the monomeric form and N-terminal chain of bone TRAP compared with the recombinant enzyme could not be accounted for by differential N-glycosylation. Despite differences in specific post-translational modifications, the recombinant PAP should be useful in future studies on the properties and regulation of the mammalian PAP enzyme.

The Influence of [3H]Taurocholate on the Biliary Excretion of [14C]Acetylprocaine Amide Ethobromide

1975 ◽  
Vol 53 (5) ◽  
pp. 888-894 ◽  
Author(s):  
S. H. Kuo ◽  
G. E. Johnson
Keyword(s):  
Biliary Excretion ◽  
Concentration Ratio ◽  
Jugular Vein ◽  
Sodium Taurocholate ◽  
Concomitant Administration ◽  
Plasma Concentration Ratio ◽  
Male Wistar Rats ◽  
The Common ◽  
Excretion Rates ◽  
Bile Samples

The biliary excretion rates of [14C]acetylprocaine amide ethobromide (acetyl-PAEB) and [3H]taurocholate, either administered alone or in combination to adult male Wistar rats, were studied. Their renal pedicles were ligated, and the common bile duct and one jugular vein cannulated. Acetyl-PAEB, 20 mg/kg, and sodium taurocholate, 70 mg/kg, were infused over a 5-min period. Blood and bile samples were collected every 10 min for 60 min. Liver samples were taken at 10 and 20 min. Approximately 100% of the administered taurocholate was excreted within 50 min. The simultaneous administration of acetyl-PAEB did not significantly alter the taurocholate excretion. The amount of the acetyl-PAEB dose excreted in 1 h was 9.4%. This was increased significantly to 16.5% when taurocholate was given concomitantly. The concentration of acetyl-PAEB in the bile increased significantly when taurocholate was given, and the ratios of its concentrations in bile–liver and bile–plasma were also increased. Taurocholate did not alter the liver–plasma concentration ratio of acetyl-PAEB. It is suggested that the concomitant administration of taurocholate increased the biliary excretion of acetyl-PAEB by facilitating its secretion by the liver into the bile.

What is the Optimal Frequency of Cycling in Automated Peritoneal Dialysis?

2000 ◽  
Vol 20 (5) ◽  
pp. 548-556 ◽  
Author(s):  
Rafael A. Perez ◽  
Peter G. Blake ◽  
Susan McMurray ◽  
Lou Mupas ◽  
Dimitrios G. Oreopoulos
Keyword(s):  
Peritoneal Dialysis ◽  
Residual Renal Function ◽  
Glucose Absorption ◽  
Published Data ◽  
Automated Peritoneal Dialysis ◽  
Optimal Frequency ◽  
Urea Clearance ◽  
Protein Excretion ◽  
The Individual ◽  
Sodium And Potassium

Objective The recent increase in the use of automated peritoneal dialysis (APD) has led to concerns about the adequacy of clearances delivered by this modality. Few clinical studies looking at the effects of varying the individual components of the APD prescription on delivered clearance have been done, and most published data are derived from computer modeling. Most controversial is the optimal frequency of exchanges per APD session. Many centers prescribe 4 to 6 cycles per night but it is unclear if this is optimal. The purpose of this study was to address at what point the beneficial effect of more frequent cycles is outweighed by the concomitant increase in the proportion of the total cycling time spent draining and filling. Methods A comparison was made between the urea and creatinine clearances (CCrs) achieved by 4 different APD prescriptions, used for 7 days each, in 18 patients. The prescriptions were for 9 hours each and were all based on 2-L dwell volumes, but differed in the frequency of exchanges. They were 5 x 2 L, 7 x 2 L, and 9 x 2 L, as well as a 50% tidal peritoneal dialysis (TPD) prescription using 14 L. Ultrafiltration, dwell time, glucose absorption, sodium and potassium removal, protein excretion, and relative cost were also compared. Clearances due to day dwells and residual renal function were not included in the calculation. Results Mean urea clearances were 7.5, 8.6, 9.1, and 8.3 L/night for the four prescriptions respectively. Urea clearance with 9 x 2 L was significantly greater than with the other three prescriptions ( p < 0 0.05). Urea clearance with 7 x 2 L and TPD were superior to 5 x 2 L ( p < 0.05). Mean CCr was 5.1, 6.1, 6.4, and 5.6 L/night, respectively. Compared to 5 x 2-L, the 7 x 2-L, 9 x 2-L, and TPD prescriptions achieved greater CCr ( p < 0.05). Taking both urea and CCr into account, 9 x 2 L was the optimal prescription in 12 of the 18 patients. Ultrafiltration and sodium and potassium removals were all significantly greater with the higher frequency prescriptions. Conclusion The 5 x 2-L prescription significantly underutilizes the potential of APD to deliver high clearances, and 7 x 2 L is a consistently superior prescription if 2-L dwells are being used. Although more costly, 9 x 2 L should be considered if higher clearances are required.

Biliary secretion in elasmobranchs. II. Hepatic uptake and biliary excretion of organic anions

1976 ◽  
Vol 230 (4) ◽  
pp. 974-981 ◽  
Author(s):  
JL Boyer ◽  
J Schwarz ◽  
N Smith
Keyword(s):  
Biliary Excretion ◽  
Binding Proteins ◽  
Organic Anion ◽  
Sodium Taurocholate ◽  
Hepatic Clearance ◽  
Hepatic Uptake ◽  
Organic Anions ◽  
Transport Systems ◽  
Raja Erinacea ◽  
Low Concentrations

[35S]Bromosulfophthalein ([35C]BSP), [14C]sodium taurocholate ([14C]NaTC), AND 10 MG OF UNLABELED BSP.and of phenol-3,6-dibromophthalein disulfonate (DBSP) per kilogram body weight were injected in the caudal artery of free-swimming dogfish sharks (Squalus acanthias) and small skates (Raja erinacea). Twenty-four hours later, 85.8 +/- 15.7% of [35S]BSP was recovered in bile and liver in dogfish and 78.4 +/- 9.9% in skates. Similar results were obtained for [14C]NaTC. Unlabeled BSP or DBSP (10 mg/kg body wt) were also selectively excreted in bile over a 4-day period and at comparable rates in both species. More than 85% of [35S]BSP, BSP, and DBSP in bile was in unconjugated form. Selective hepatic clearance of BSP occurred despite nonselective binding to liver homogenates and very low concentrations of binding proteins in liver cytosol. Analysis of the organic anion plasma disappearance curves suggest that the clearance of anions into bile in elasmobranchs is delayed disproportionately relative to hepatic uptake. Albumin-BSP infusions did not prevent selective hepatic uptake of [35S]BSP, although biliary excretion was delayed further. These studies demonstrate that transport systems for biliary excretion of organic anions evolved prior to migration of marine life from the sea and relatively independently of intrahepatic conjugation and organic anion-binding proteins.

scholarly journals Degradation of Benzo[a]pyrene by the Litter-Decomposing Basidiomycete Stropharia coronilla: Role of Manganese Peroxidase

2003 ◽  
Vol 69 (7) ◽  
pp. 3957-3964 ◽  
Author(s):  
Kari T. Steffen ◽  
Annele Hatakka ◽  
Martin Hofrichter
Keyword(s):  
Molecular Mass ◽  
Environmental Protection Agency ◽  
Manganese Peroxidase ◽  
Total Concentration ◽  
Basal Medium ◽  
Tween 80 ◽  
Ligninolytic Enzyme ◽  
Polycyclic Aromatic ◽  
The Individual

ABSTRACT The litter-decomposing basidiomycete Stropharia coronilla, which preferably colonizes grasslands, was found to be capable of metabolizing and mineralizing benzo[a]pyrene (BaP) in liquid culture. Manganese(II) ions (Mn2+) supplied at a concentration of 200 μM stimulated considerably both the conversion and the mineralization of BaP; the fungus metabolized and mineralized about four and twelve times, respectively, more of the BaP in the presence of supplemental Mn2+ than in the basal medium. This stimulating effect could be attributed to the ligninolytic enzyme manganese peroxidase (MnP), whose activity increased after the addition of Mn2+. Crude and purified MnP from S. coronilla oxidized BaP efficiently in a cell-free reaction mixture (in vitro), a process which was enhanced by the surfactant Tween 80. Thus, 100 mg of BaP liter−1 was converted in an in vitro reaction solution containing 1 U of MnP ml−1 within 24 h. A clear indication was found that BaP-1,6-quinone was formed as a transient metabolite, which disappeared over the further course of the reaction. The treatment of a mixture of 16 different polycyclic aromatic hydrocarbons (PAHs) selected by the U.S. Environmental Protection Agency as model standards for PAH analysis (total concentration, 320 mg liter−1) with MnP resulted in concentration decreases of 10 to 100% for the individual compounds, and again the stimulating effect of Tween 80 was observed. Probably due to their lower ionization potentials, poorly bioavailable, high-molecular-mass PAHs such as BaP, benzo(g,h,i)perylene, and indeno(1,2,3-c,d)pyrene were converted to larger extents than low-molecular-mass ones (e.g., phenanthrene and fluoranthene).

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