The Experts below are selected from a list of 126 Experts worldwide ranked by ideXlab platform
Toshio Yamamoto - One of the best experts on this subject based on the ideXlab platform.
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Type II Crigler-Najjar syndrome with intrahepatic cholestasis
Journal of Gastroenterology, 1994Co-Authors: Atsushi Kagita, Akira Kambe, Yukihiko Adachi, Toshinori Kamisako, Toshio YamamotoAbstract:A 58-year-old Japanese man was admitted to our hospital with appendicitis and marked unconjugated hyperBilirubinemia (11.6 mg/dl). The jaundice worsened following appendectomy, and the directreacting Bilirubin increased, probably due to the ceftizoxime administered postoperatively. Bilirubin Diglucuronide was the main component of the serum direct-reacting Bilirubin (51%) in serum measured by liquid chromatography. Because the discontinuation of ceftizoxime did not markedly improve the jauncice, epomediol, 200 mg tid, was administered orally. There was a marked decrease of serum Bilirubin with an increase in the δ Bilirubin/(conjugated Bilirubin + δ Bilirubin) ratio. After improvement of jaundice to below the pre-surgical level (4.4 mg/dl), we analyzed the duodenal bile for Bilirubin fractions; those showed a marked reduction in Bilirubin Diglucuronide and a marked increase in Bilirubin monoglucuronide, which was consistent with type II Crigler-Najjar syndrom. A marked increase of Bilirubin Diglucuronide in serum of this patient during cholestasis suggests that Bilirubin conjugation proceeds in this syndrome when excretion of conjugated Bilirubin decreases.
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functional integrity of hepatocyte canalicular membrane transport of taurocholate and Bilirubin Diglucuronide in eisai hyperBilirubinuria rats
Life Sciences, 1993Co-Authors: Yukihiko Adachi, Hiroaki Kobayashi, Mika Shouji, Motokazu Kitano, Yoshifumi Okuyama, Toshio YamamotoAbstract:Abstract Eisai hyperBilirubinuria rats (EHBR) are characterized by conjugated hyperBilirubinemia, and impaired or defective excretion of Bilirubin, reduced glutathione and other organic anions from hepatocytes. Hepatocyte canalicular membrane vesicles (CMV) from EHBR and normal SD rats were studied with regard to taurocholate (TC) transport driven by ATP or a membrane potential and bicarbonate-stimulated Bilirubin Diglucuronide (BDG) transport. ATP-dependent uptake or association of BDG with CMV was also studied in both strains of rats. No significant differences in the uptake of TC and BDG by CMV were observed. This indicates the functional integrity of the canalicular transporters for both organic anions in EHBR. Biliary excretion of taurolithocholic acid sulfate (TLCS) is defective in EHBR. However, TLCS inhibited ATP-dependent TC uptake by SD rat CMV competitively, which may be against the hypothesis that a common organic anion carrier is defective in canalicular membranes of jaundiced rats.
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Bilirubin Diglucuronide transport by rat liver canalicular membrane vesicles stimulation by bicarbonate ion
Hepatology, 1991Co-Authors: M Yukihiko D Adachi, Hiroaki Kobayashi, Yoshiaki Kurumi, Mika Shouji, Motokazu Kitano, Toshio YamamotoAbstract:The purpose of this study was to provide further insight into the mechanism of Bilirubin Diglucuronide excretion through the hepatocyte canalicular membrane by investigating the uptake of (3H)Bilirubin Diglucuronide by purified canalicular membrane vesicles of rat liver. The uptake was analyzed by a rapid filtration technique. The difference between vesicle-associated (3H)Bilirubin Diglucuronide at 37° C and at 0° C during the initial 1 min was regarded as uptake. Twenty second uptake was saturated by increasing the (3H)Bilirubin Diglucuronide concentration at a vesicle-inside-directed 100 mmol/L KCl gradient (Km = 75 μmol/L, Vmax = 320 pmol/mg protein 20 sec at 37° C). No sodium dependency was observed. When canalicular membrane vesicles were preincubated with nonlabeled Bilirubin Diglucuronide, the uptake increased 1.3-fold (transstimulation). Vesicle-inside-positive potential induced by valinomycin and potassium caused a 1.4-fold increase in the uptake. When Cl− was replaced by equivalent ion concentrations of SO, HCO, NO and SCN−, the uptake was 78%, 244%, 68% and 50%, respectively, and specific stimulation by HCO was observed (Km = 75 μmol/L, Vmax = 700 pmol/mg protein 20 sec at a vesicle-inside-directed 100 mmol/L KHCO3 gradient at 37° C). The uptake was inhibited in a dose-dependent manner by the addition of 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid. The uptake was ATP independent. From these results, it was concluded that Bilirubin Diglucuronide transport through the canalicular membrane is carrier mediated, electrogenic and stimulated by HCO. (HEPATOLOGY 1991;14:1251–1258.)
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The effects of temporary occlusion of the superior mesenteric vein or splenic vein on biliary Bilirubin and bile acid excretion in rats
Journal of Laboratory and Clinical Medicine, 1991Co-Authors: Yukihiko Adachi, Toshinori Kamisako, Toshio YamamotoAbstract:Abstract To elucidate the possible implication of hepatic blood supply to the occurrence of hepatolithiasis, the rat superior mesenteric vein, which drains blood from the intestine, or the splenic vein, which drains from the spleen, was occluded for 30 minutes. Changes in the hepatic oxygen saturation index, intrahepatic uridine diphosphate-glucuronic acid concentration, bile flow, and the excretion of Bilirubin as well as its fraction, along with bile acid in bile before and after the procedure, were observed. In association with superior mesenteric vein occlusion, oxygen saturation index, hepatic uridine diphosphate-glucuronic acid concentration, bile flow, bile acid concentration in bile, and percentage of biliary Bilirubin Diglucuronide were all decreased. incubation of bile under sterile conditions from rats with occluded superior mesenteric veins resulted in precipitation of mainly calcium salt of fatty acid. in contrast, splenic vein occlusion caused no changes except for a decrease in biliary Bilirubin concentration. incubation of bile from rats with occluded splenic veins did not induce precipitation. From these findings it can be concluded that blood flow in the superior mesenteric vein is the primary source of oxygen supply to the rat liver and that this vein plays an important role in maintaining bile flow, bile acid excretion, and Bilirubin conjugation and in preventing the precipitation of bile (possibly preventing hepatolithlasis).
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Bilirubin Diglucuronide as the main source for in vitro formation of delta Bilirubin
Journal of Clinical Laboratory Analysis, 1991Co-Authors: Yukihiko Adachi, Akira Kambe, Masaki Yamashita, Toshio YamamotoAbstract:: To clarify which of the Bilirubin moieties is responsible for the formation of Bilirubin bonded to albumin (delta Bilirubin) in icteric serum, the in vitro formation of delta Bilirubin from bile acid-free Bilirubin glucuronides and unconjugated Bilirubin was examined by high-performance liquid chromatography. Bovine serum albumin (150 mumol/liter) was mixed with equimolar Bilirubin Diglucuronide (BDG), Bilirubin monoglucuronide (BMG), or unconjugated Bilirubin (UCB) and incubated in the dark at 37 degrees C under argon gas saturation. Although no delta Bilirubin was formed immediately, formation eventually occurred and increased with time. A similar amount of delta Bilirubin was formed when human serum albumin was used instead of bovine serum albumin. Of the three types of Bilirubin, BDG was found to be the greatest source of delta Bilirubin, whereas UCB produced the least. On the other hand, photoirradiation of a mixture of bovine serum albumin and UCB at a molar ratio of 1:1 resulted 6 hr later in the formation of three times as much delta Bilirubin as in nonirradiated specimens. This photoinduced delta Bilirubin formation increased further when the UCB/albumin molar ratio was increased to 2:1.
Yukihiko Adachi - One of the best experts on this subject based on the ideXlab platform.
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Type II Crigler-Najjar syndrome with intrahepatic cholestasis
Journal of Gastroenterology, 1994Co-Authors: Atsushi Kagita, Akira Kambe, Yukihiko Adachi, Toshinori Kamisako, Toshio YamamotoAbstract:A 58-year-old Japanese man was admitted to our hospital with appendicitis and marked unconjugated hyperBilirubinemia (11.6 mg/dl). The jaundice worsened following appendectomy, and the directreacting Bilirubin increased, probably due to the ceftizoxime administered postoperatively. Bilirubin Diglucuronide was the main component of the serum direct-reacting Bilirubin (51%) in serum measured by liquid chromatography. Because the discontinuation of ceftizoxime did not markedly improve the jauncice, epomediol, 200 mg tid, was administered orally. There was a marked decrease of serum Bilirubin with an increase in the δ Bilirubin/(conjugated Bilirubin + δ Bilirubin) ratio. After improvement of jaundice to below the pre-surgical level (4.4 mg/dl), we analyzed the duodenal bile for Bilirubin fractions; those showed a marked reduction in Bilirubin Diglucuronide and a marked increase in Bilirubin monoglucuronide, which was consistent with type II Crigler-Najjar syndrom. A marked increase of Bilirubin Diglucuronide in serum of this patient during cholestasis suggests that Bilirubin conjugation proceeds in this syndrome when excretion of conjugated Bilirubin decreases.
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functional integrity of hepatocyte canalicular membrane transport of taurocholate and Bilirubin Diglucuronide in eisai hyperBilirubinuria rats
Life Sciences, 1993Co-Authors: Yukihiko Adachi, Hiroaki Kobayashi, Mika Shouji, Motokazu Kitano, Yoshifumi Okuyama, Toshio YamamotoAbstract:Abstract Eisai hyperBilirubinuria rats (EHBR) are characterized by conjugated hyperBilirubinemia, and impaired or defective excretion of Bilirubin, reduced glutathione and other organic anions from hepatocytes. Hepatocyte canalicular membrane vesicles (CMV) from EHBR and normal SD rats were studied with regard to taurocholate (TC) transport driven by ATP or a membrane potential and bicarbonate-stimulated Bilirubin Diglucuronide (BDG) transport. ATP-dependent uptake or association of BDG with CMV was also studied in both strains of rats. No significant differences in the uptake of TC and BDG by CMV were observed. This indicates the functional integrity of the canalicular transporters for both organic anions in EHBR. Biliary excretion of taurolithocholic acid sulfate (TLCS) is defective in EHBR. However, TLCS inhibited ATP-dependent TC uptake by SD rat CMV competitively, which may be against the hypothesis that a common organic anion carrier is defective in canalicular membranes of jaundiced rats.
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The effects of temporary occlusion of the superior mesenteric vein or splenic vein on biliary Bilirubin and bile acid excretion in rats
Journal of Laboratory and Clinical Medicine, 1991Co-Authors: Yukihiko Adachi, Toshinori Kamisako, Toshio YamamotoAbstract:Abstract To elucidate the possible implication of hepatic blood supply to the occurrence of hepatolithiasis, the rat superior mesenteric vein, which drains blood from the intestine, or the splenic vein, which drains from the spleen, was occluded for 30 minutes. Changes in the hepatic oxygen saturation index, intrahepatic uridine diphosphate-glucuronic acid concentration, bile flow, and the excretion of Bilirubin as well as its fraction, along with bile acid in bile before and after the procedure, were observed. In association with superior mesenteric vein occlusion, oxygen saturation index, hepatic uridine diphosphate-glucuronic acid concentration, bile flow, bile acid concentration in bile, and percentage of biliary Bilirubin Diglucuronide were all decreased. incubation of bile under sterile conditions from rats with occluded superior mesenteric veins resulted in precipitation of mainly calcium salt of fatty acid. in contrast, splenic vein occlusion caused no changes except for a decrease in biliary Bilirubin concentration. incubation of bile from rats with occluded splenic veins did not induce precipitation. From these findings it can be concluded that blood flow in the superior mesenteric vein is the primary source of oxygen supply to the rat liver and that this vein plays an important role in maintaining bile flow, bile acid excretion, and Bilirubin conjugation and in preventing the precipitation of bile (possibly preventing hepatolithlasis).
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Uptake of Bilirubin glucuronides by isolated rat hepatocytes
Gastroenterologia Japonica, 1991Co-Authors: Yukihiko Adachi, Namita Roy Chowdhury, Rolf K H Kinne, Thao Tran, Jayanta Roy Chowdhury, Lorenz Theilmann, Irwin M AriasAbstract:The uptake of Bilirubin Diglucuronide (BDG) into isolated rat hepatocytes was investigated in order to characterize the mechanism by which bile pigments are transported by the liver. The BDG uptake by hepatocytes was saturable. The uptake was inhibited by Bilirubin, sulfobromophthalein, and Bilirubin monoglucuronide, but not by taurocholate. The uptake was not affected by replacement of sodium with other cations except for choline. Only when sodium was replaced with choline, was significant decrease in uptake observed. When chloride was replaced with nitrate, BDG uptake decreased, but it was not changed by replacement with sulfate. Metabolic inhibitors did not affect BDG uptake significantly. Thus bile pigments share a common sodium-independent and electrogenic potential-dependent transporter in liver cell membranes. A high concentration of albumin interferes with BDG uptake.
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Bilirubin Diglucuronide as the main source for in vitro formation of delta Bilirubin
Journal of Clinical Laboratory Analysis, 1991Co-Authors: Yukihiko Adachi, Akira Kambe, Masaki Yamashita, Toshio YamamotoAbstract:: To clarify which of the Bilirubin moieties is responsible for the formation of Bilirubin bonded to albumin (delta Bilirubin) in icteric serum, the in vitro formation of delta Bilirubin from bile acid-free Bilirubin glucuronides and unconjugated Bilirubin was examined by high-performance liquid chromatography. Bovine serum albumin (150 mumol/liter) was mixed with equimolar Bilirubin Diglucuronide (BDG), Bilirubin monoglucuronide (BMG), or unconjugated Bilirubin (UCB) and incubated in the dark at 37 degrees C under argon gas saturation. Although no delta Bilirubin was formed immediately, formation eventually occurred and increased with time. A similar amount of delta Bilirubin was formed when human serum albumin was used instead of bovine serum albumin. Of the three types of Bilirubin, BDG was found to be the greatest source of delta Bilirubin, whereas UCB produced the least. On the other hand, photoirradiation of a mixture of bovine serum albumin and UCB at a molar ratio of 1:1 resulted 6 hr later in the formation of three times as much delta Bilirubin as in nonirradiated specimens. This photoinduced delta Bilirubin formation increased further when the UCB/albumin molar ratio was increased to 2:1.
Hiroaki Kobayashi - One of the best experts on this subject based on the ideXlab platform.
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functional integrity of hepatocyte canalicular membrane transport of taurocholate and Bilirubin Diglucuronide in eisai hyperBilirubinuria rats
Life Sciences, 1993Co-Authors: Yukihiko Adachi, Hiroaki Kobayashi, Mika Shouji, Motokazu Kitano, Yoshifumi Okuyama, Toshio YamamotoAbstract:Abstract Eisai hyperBilirubinuria rats (EHBR) are characterized by conjugated hyperBilirubinemia, and impaired or defective excretion of Bilirubin, reduced glutathione and other organic anions from hepatocytes. Hepatocyte canalicular membrane vesicles (CMV) from EHBR and normal SD rats were studied with regard to taurocholate (TC) transport driven by ATP or a membrane potential and bicarbonate-stimulated Bilirubin Diglucuronide (BDG) transport. ATP-dependent uptake or association of BDG with CMV was also studied in both strains of rats. No significant differences in the uptake of TC and BDG by CMV were observed. This indicates the functional integrity of the canalicular transporters for both organic anions in EHBR. Biliary excretion of taurolithocholic acid sulfate (TLCS) is defective in EHBR. However, TLCS inhibited ATP-dependent TC uptake by SD rat CMV competitively, which may be against the hypothesis that a common organic anion carrier is defective in canalicular membranes of jaundiced rats.
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Bilirubin Diglucuronide transport by rat liver canalicular membrane vesicles stimulation by bicarbonate ion
Hepatology, 1991Co-Authors: M Yukihiko D Adachi, Hiroaki Kobayashi, Yoshiaki Kurumi, Mika Shouji, Motokazu Kitano, Toshio YamamotoAbstract:The purpose of this study was to provide further insight into the mechanism of Bilirubin Diglucuronide excretion through the hepatocyte canalicular membrane by investigating the uptake of (3H)Bilirubin Diglucuronide by purified canalicular membrane vesicles of rat liver. The uptake was analyzed by a rapid filtration technique. The difference between vesicle-associated (3H)Bilirubin Diglucuronide at 37° C and at 0° C during the initial 1 min was regarded as uptake. Twenty second uptake was saturated by increasing the (3H)Bilirubin Diglucuronide concentration at a vesicle-inside-directed 100 mmol/L KCl gradient (Km = 75 μmol/L, Vmax = 320 pmol/mg protein 20 sec at 37° C). No sodium dependency was observed. When canalicular membrane vesicles were preincubated with nonlabeled Bilirubin Diglucuronide, the uptake increased 1.3-fold (transstimulation). Vesicle-inside-positive potential induced by valinomycin and potassium caused a 1.4-fold increase in the uptake. When Cl− was replaced by equivalent ion concentrations of SO, HCO, NO and SCN−, the uptake was 78%, 244%, 68% and 50%, respectively, and specific stimulation by HCO was observed (Km = 75 μmol/L, Vmax = 700 pmol/mg protein 20 sec at a vesicle-inside-directed 100 mmol/L KHCO3 gradient at 37° C). The uptake was inhibited in a dose-dependent manner by the addition of 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid. The uptake was ATP independent. From these results, it was concluded that Bilirubin Diglucuronide transport through the canalicular membrane is carrier mediated, electrogenic and stimulated by HCO. (HEPATOLOGY 1991;14:1251–1258.)
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hepatic uptake of Bilirubin Diglucuronide analysis by using sinusoidal plasma membrane vesicles
Journal of Biochemistry, 1990Co-Authors: Yukihiko Adachi, Hiroaki Kobayashi, Jayanta Roychowdhury, Namita Roychowdhury, Rolf K H Kinne, Thao Tran, Irwin M AriasAbstract:: In order to characterize the mechanism for Bilirubin transport in the liver, the uptake of Bilirubin Diglucuronide (BDG) into purified sinusoidal plasma membrane vesicles was investigated. BDG uptake was saturable, and was inhibited by sulfobromophthalein and unconjugated Bilirubin, but was not affected by sodium taurocholate. BDG uptake was sodium-independent and was stimulated by intravesicular Bilirubin or BDG (trans-stimulation). BDG transport showed strong potential sensitivity; vesicle inside-negative membrane potential created by different anion gradients inhibited BDG uptake whereas vesicle inside-positive membrane potential generated by potassium gradients and valinomycin markedly stimulated BDG transport. These data suggest that BDG, sulfobromophthalein, and probably unconjugated Bilirubin share a common transporter in liver cells which is sodium independent, membrane-potential-dependent and capable of exchange. The direction of transport in vivo may be governed by the intracellular concentration of BDG and of other yet unidentified organic anions sharing this transporter.
Irwin M Arias - One of the best experts on this subject based on the ideXlab platform.
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Two distinct mechanisms for Bilirubin glucuronide transport by rat bile canalicular membrane vesicles. Demonstration of defective ATP-dependent transport in rats (TR-) with inherited conjugated hyperBilirubinemia.
Journal of Clinical Investigation, 1992Co-Authors: Toshirou Nishida, Zenaida Gatmaitan, Jayanta Roy-chowdhry, Irwin M AriasAbstract:Bilirubin is conjugated with glucuronic acid in hepatocytes and subsequently secreted in bile. The major conjugate is Bilirubin Diglucuronide. Using sealed vesicles which are primarily derived from the canalicular (CMV) and sinusoidal (SMV) membrane vesicle domains of the plasma membrane of hepatocytes, we demonstrated that Bilirubin glucuronides are transported by CMV by both ATP- and membrane potential-dependent transport systems. In CMV from normal rats, these processes are additive. In CMV from TR- rats, which have an autosomal recessively inherited defect in biliary secretion of nonbile acid organic anions, ATP-dependent transport of Bilirubin Diglucuronide was absent whereas the membrane potential driven system was retained. Other canalicular ATP-dependent transport systems, which were previously described for organic cations and bile acids, are functionally retained in TR- rats. Our study indicates that Bilirubin glucuronides are primarily secreted into the bile canaliculus by an ATP-dependent mechanism which is defective in an animal model of the human Dubin-Johnson syndrome.
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Two Distinct Mechanisms for Bilirubin Glucuronide Transport by Rat Bile Canalicular Membrane Vesicles
1992Co-Authors: Toshirou Nishida, Irwin M Arias, Zenaida Gatmaitan, Jayanta Roy-chowdhry, Marion BessinAbstract:Bilirubin is conjugated with glucuronic acid in hepatocytes and subsequently secreted in bile. The major conjugate is Bilirubin Diglucuronide. Using sealed vesicles which are primarily derived from the canalicular (CMV) and sinusoidal (SMV) membrane vesicle domains ofthe plasma membrane ofhepatocytes, we demonstrated that Bilirubin glucuronides are transported byCMV by both ATP- and membrane potential-dependent transport systems. InCMV from normal rats, these processes are additive. In CMV from TR- rats, which have an autosomal recessively inherited defect in biliary secretion of nonbile acid organic anions, ATP-dependent transport ofBilirubin Diglucuronide was absent whereas the membrane potential driven system was retained. Other canalicular ATP-dependent transport systems, which were previously described for organic cations and bile acids, are functionally retained in TR- rats. Our study indicates that Bilirubin glucuronides are primarily secreted into the bile canaliculus by an ATP-dependent mechanism which is defective in an animal model ofthehuman DubinJohnson syndrome. (J. Clin. Invest. 1992.90:2130-2135.) Key words: ATP-dependent transport * Bilirubin glucuronides* canalicular transport * inheritable jaundice (Dubin-Johnson syn
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Uptake of Bilirubin glucuronides by isolated rat hepatocytes
Gastroenterologia Japonica, 1991Co-Authors: Yukihiko Adachi, Namita Roy Chowdhury, Rolf K H Kinne, Thao Tran, Jayanta Roy Chowdhury, Lorenz Theilmann, Irwin M AriasAbstract:The uptake of Bilirubin Diglucuronide (BDG) into isolated rat hepatocytes was investigated in order to characterize the mechanism by which bile pigments are transported by the liver. The BDG uptake by hepatocytes was saturable. The uptake was inhibited by Bilirubin, sulfobromophthalein, and Bilirubin monoglucuronide, but not by taurocholate. The uptake was not affected by replacement of sodium with other cations except for choline. Only when sodium was replaced with choline, was significant decrease in uptake observed. When chloride was replaced with nitrate, BDG uptake decreased, but it was not changed by replacement with sulfate. Metabolic inhibitors did not affect BDG uptake significantly. Thus bile pigments share a common sodium-independent and electrogenic potential-dependent transporter in liver cell membranes. A high concentration of albumin interferes with BDG uptake.
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hepatic uptake of Bilirubin Diglucuronide analysis by using sinusoidal plasma membrane vesicles
Journal of Biochemistry, 1990Co-Authors: Yukihiko Adachi, Hiroaki Kobayashi, Jayanta Roychowdhury, Namita Roychowdhury, Rolf K H Kinne, Thao Tran, Irwin M AriasAbstract:: In order to characterize the mechanism for Bilirubin transport in the liver, the uptake of Bilirubin Diglucuronide (BDG) into purified sinusoidal plasma membrane vesicles was investigated. BDG uptake was saturable, and was inhibited by sulfobromophthalein and unconjugated Bilirubin, but was not affected by sodium taurocholate. BDG uptake was sodium-independent and was stimulated by intravesicular Bilirubin or BDG (trans-stimulation). BDG transport showed strong potential sensitivity; vesicle inside-negative membrane potential created by different anion gradients inhibited BDG uptake whereas vesicle inside-positive membrane potential generated by potassium gradients and valinomycin markedly stimulated BDG transport. These data suggest that BDG, sulfobromophthalein, and probably unconjugated Bilirubin share a common transporter in liver cells which is sodium independent, membrane-potential-dependent and capable of exchange. The direction of transport in vivo may be governed by the intracellular concentration of BDG and of other yet unidentified organic anions sharing this transporter.
M Osnes - One of the best experts on this subject based on the ideXlab platform.
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brown pigment stones in the common bile duct reduced Bilirubinate diconjugate in bile
Scandinavian Journal of Gastroenterology, 2000Co-Authors: O Sandstad, V Skar, Terje Osnes, P Urdal, M OsnesAbstract:Background: Bilirubin is the main component of most common bile duct stones. Normally, almost all Bilirubin in bile is conjugated to glucuronic acid or some other sugar moiety. These conjugates are unstable and liable to deconjugation. Unconjugated Bilirubin is insoluble and may precipitate as the calcium salt found in brown pigment stones. The pattern of Bilirubin conjugates in common duct bile of patients with choledocholithiasis has been unknown. Methods: In a clinical series of 55 patients with choledocholithiasis common-duct bile was aspirated, and the Bilirubin conjugates analyzed with high-performance liquid chromatography. One stone from each patient was analyzed for cholesterol and Bilirubin content to determine stone type. Results: Sixteen patients had cholesterol stones, 38 patients had brown pigment stones, and 1 patient had a black stone. Patients with pigment stones had a lower percentage of Bilirubin Diglucuronide (median, 60.3%; interquartile range, 49.7%-67.3%) than patients with choleste...
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β-Glucuronidase in common duct bile, methodological aspects, variation of pH optima and relation to gallstones
Scandinavian Journal of Clinical & Laboratory Investigation, 1997Co-Authors: Terje Osnes, V Skar, O Sandstad, M OsnesAbstract:β-Glucuronidase of human or bacterial origin may deconjugate Bilirubin Diglucuronide, causing pigment gallstones. Intrinsic interference by biliary compounds must be minimized for accurate assay of β-glucuronidase.We report a modified ion-pair extraction of interfering substances by tetrahexylammonium chloride (THAC) in ethyl acetate in the presence of albumin, and a microtitre plate assay for biliary β-glucuronidase activity in bile with the substrate β-nitrophenol-glucuronide. Adding albumin improved the recovery of β-glucuronidase activity to 99.8% (CV 1.9%), and 92.2% of the Bilirubin in bile samples was extracted in one step. Competitive inhibition was overcome by increasing the substrate concentration. In endoscopically obtained common duct bile from 44 patients, five different β-glucuronidase activity peaks were identified, at pH 3.9, 4.8, 5.3, 5.8 and 7.2. The pH profiles were classified into one bacterial pattern and five patterns for presumed human β-glucuronidase. Of the latter patterns, four d...
