• Biomedical Science Letters
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• v.10 no.4
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• pp.429-434
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• 2004

The effects of intravenous administration of high concentration of taurocholic acid (TCA) on cathepsin B and D, and acid phosphatase activities in rat liver lysosome were studied. These liver lysosomal enzymes were determined from the experimental rats with choledocho-caval shunt (CCS). The activities of liver lysosomal cathepsin B and D, and acid phosphatase were found to be significantly increased in the CCS plus TCA injection group than in control group, such as group of CCS alone group. However, these hepatic enzyme activities did not change in the CCS plus tauroursodeoxycholic acid injection group. The above results suggest that TCA stimulates the biosynthesis of the lysosomal cathepsin B and D, and acid phosphatase in the liver.

• Applied Microscopy
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• v.28 no.1
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• pp.73-82
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• 1998

To elucidate how microfilaments and vesicles participate in bile formation, the pericanalicular cytoplasms were observed in the liver of rats treated with taurocholic acid by deep etching with rapid freezing, and copmpared them with the findings on convensional thin sections. The microfilaments were identified around the bile canaliculi in the forms of core filaments of microvilli, filaments of pericanalicular web running in parallel to the border of bile canaliculi, and filaments on the junctional complex. In taurocholic acid-treated rats, microfilaments could be visualized around the bile canaliculi and along their borders. The microfilaments appeared to be installed to link to both the canalicular membrane and vesicles. Such specialized microfilaments are considered to participate in the translocation of vesicles in the pericanalicular cytoplasm. From the evidence, it is assumed that the microfilament induces the vesicles to transport and fuse to bile canalicull into which bile acids is secreted by exocytosis.

• Biomedical Science Letters
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• v.10 no.2
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• pp.93-98
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• 2004

The effects of intravenously administered of high concentration of taurocholic acid (TCA) on $\alpha$-D- and $\beta$-D-mannosidase activities in rat liver lysosomes were studied. These liver lysosomal enzymes, and serum lysosomal $\alpha$-D- and $\beta$-D-mannosidase isozymes activities were determined in experimental rats with common bile duct ligation (CBDL). The liver lysosomal $\beta$-D-mannosidase activity as well as the serum lysosomal $\alpha$-D- and $\beta$-D-mannosidase isozymes activities were found to be significantly increased in the CBDL plus TCA injected group than in the control group such as CBDL alone group. However, the liver lysosomal $\alpha$-D-mannosidase activity was found to be significantly decreased in the CBDL plus TCA injected group. The above results suggest that TCA repress the biosynthesis of the lysosomal $\alpha$-D-mannosidase and induce the biosynthesis of the lysosomal $\beta$-D-mannosidase in the liver. And that the elevated serum lysosomal $\alpha$-D- and $\beta$-D-mannosidase isozymes activities are most likely due to increased hepatocyte membrane permeability caused by TCA mediated liver cell necrosis.

• Biomedical Science Letters
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• v.12 no.2
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• pp.91-97
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• 2006

The effects of intravenous administration of high concentration of taurocholic acid (TCA) on monoamine oxidase (MAO) A and B activities in rat liver mitochondria and microsomes were studied. These liver subcellular organelles and serum MAO activities were determined from the experimental rats with choledocho-caval shunt (CCS). The Michaelis-Menten constants in these hepatic enzymes were also measured. The activities of mitochondrial MAO A and B, and microsomal MAO B as well as their $V_{max}$ values were found to be decreased significantly in CCS plus TCA injected group then in the control group, such as CCS alone groups. However their $K_m$ values in the experimental groups did not vary. MAO of serum appeared in the CCS plus TCA injected groups only. The above results suggest that TCA represses biosynthesis of the MAO in the liver. The MAO of serum is believed to be caused by the increment of membrane permeability of hepatocytes upon TCA mediated liver cell necrosis.

• Biomedical Science Letters
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• v.13 no.2
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• pp.135-140
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• 2007

The possible mechanism of decreased catechol-O-methyltransferase (COMT) activity in cholestatic rat liver was studied. Hepatic and serum COMT activities were determined from the experimental rats with choledocho-caval shunt (CCS). The Michaelis-Menten constants in this hepatic enzyme was also measured. The activities of cytosolic, mitochondrial and mircosomal COMT as well as their $V_{max}$ values were found to be decreased significantly in CCS plus taurocholic acid (TCA) injected group than in the control group, such as CCS alone groups. However, their $K_m$ values in the experimental groups did not vary. Seru4m COMT activity increased slightly in the CCS plus TCA injerted group than in the control group. The above results suggest that TCA represses biosynthesis of the COMT in the liver, The elevated activity of the serum COMT is believed to be caused by the increment of membrane permeability of hepatocytes upon TCA mediated liver cell necrosis.

• Biomolecules & Therapeutics
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• v.4 no.2
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• pp.162-166
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• 1996

This study was done to investigate whether cholic acid derivatives have anti-stress activity and what is a cause of this anti-stress effect. Seven cholic acid derivatives (cholic acid, taurocholic acid, ursodeoxycholic acid, tauroursodeoxychoic acid, chenodeoxy cholic acid, dehydrocholic acid, hyodeoxycholic acid) were used, silymarin and valproic acid were used as positive controls. Stress was induced by restraint immobilization technique plus water immersion (24hrs) and adrenal weight, spleen weight, adrenal ascorbic acid, serum cholesterol, lactate dehydrogenase (LDH), alkaline phosphatase (ALP), adrenal cholesterol, glucose and corticosterone levels were measured as stress indicators. Most cholic acid derivatives markedly decreased the adrenal weight, and TUDCA and DHCA increased the spleen weight. The restraint stress induced increments in serum LDH, ALP and cholesterol were attenuated by most cholic acid derivatives. Cholic acid, taurocholic acid and tauroursodeoxycholic acid only increased the content of adrenal ascorbate. While valproic acid showed an inhibitory effect against stress, silymarin did not. Our findings suggest that most cholic acid derivatives have anti-stress effect and that their anti-stress effect is, in part, related to choleretic activity.

• Biomedical Science Letters
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• v.11 no.4
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• pp.473-479
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• 2005

Possible mechanism of decreased catechol-O-methyltransferase (COMT) activity in cholestatic rat liver was studied. Hepatic and serum COMT activities were determined from the experimental rats with common bile duct ligation (CBDL). The Michaelis-Menten constants in this hepatic enzyme were also measured. The activities of cytosolic, mitochondrial and mircosomal COMT as well as their Vmax values were found to be decreased significantly in CBDL plus taurocholic acid (TCA) injected group than in the control group, such as CBDL alone groups. However, their Km values in the experimental groups did not vary. Serum COMT activity increased slightly in the CBDL plus TCA injected group than in the control group. The above results suggest that TCA represses biosynthesis of the COMT in the liver. The elevated activity of the serum COMT is believed to be caused by the increment of membrane permeability of hepatocytes upon TCA mediated liver cell necrosis.

• Biomedical Science Letters
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• v.11 no.4
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• pp.503-508
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• 2005

Possible mechanisms of increased serum aryl sulfotransferase (AST) isozyme activities in cholestatic rats were studied. Serum AST-I, II and -III, IV isozymes activities were determined from the experimental rats with common bile duct ligation (CBDL) or choledocho-caval shunt (CCS). The activities of serum AST-I, II and -III, IV isozymes were found to be increased significantly in both the CCS plus taurocholic acid (TCA) injected group, and the CBDL plus TCA group than those in each control group, such as CCS or CBDL alone groups. The above results suggest that the elevated serum AST most likely due to increased hepatocyte membrane permeability caused by TCA mediated liver cell necrosis.

• Biomedical Science Letters
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• v.11 no.1
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• pp.37-43
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• 2005

The possible mechanisms of increased aryl sulfotransferase (AST) isozymes activities in cholestatic rat liver were studied. Hepatic AST-I, II and -III, IV activities were determined from the experimental rats with common bile duct ligation (CBDL). The Michaelis-Menten constants in these hepatic enzymes were also measured. The activities of mitochondrial AST-I, II and -III, IV, and microsomal AST-III, IV as well as their Vmax values were found to be increased significantly in CBDL plus taurocholic acid (TCA) injected group than in the control group, such as CBDL alone groups. However, their Km values in the experimental groups did not vary. The results suggest that TCA stimulates biosynthesis of the AST in the liver.

• Biomedical Science Letters
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• v.10 no.4
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• pp.421-427
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• 2004

The possible mechanisms of decreased monoamine oxidase (MAO) A and B activities in cholestatic rat liver were studied. Hepatic and serum MAG activities were determined from the experimental rats with common bile duct ligation (CBDL). The Michaelis-Menten constants in these hepatic enzymes were also measured. The activities of mitochondrial MAO A and B, and mircosomal MAO B as well as their Vmax values were found to be decreased significantly in CBDL plus taurocholic acid (TCA) injected group than in the control group, such as CBDL alone groups. However, their Km values in the experimental groups did not vary. Serum MAO activity increased significantly in the CBDL plus TCA injected group than in the control group. The above results suggest that TCA represses biosynthesis of the MAO in the liver. The elevated activity of the serum MAO is believed to be caused by the increment of membrane permeability ofhepatocytes upon TCA mediated liver cell necrosis.