Formation of 7α‐ and 7β‐hydroxylated bile acid precursors from 27‐hydroxycholesterol in human liver microsomes and mitochondria

Junichi Shoda, Anders Toll, Magnus Axelson, Fritz Pieper, Kjell Wikvall, Jan Sjövall – 1 March 1993 – In a search for enzymes involved in the formation of bile acids from 27‐hydroxycholesterol in humans, the metabolism of this and other side‐chain oxygenated steroids was studied in human liver microsomes and mitochondria. The microsomal fraction contained enzyme(s) catalyzing 7α‐hydroxylation of 27‐hydroxycholesterol and 3β‐hydroxy‐5‐cholestenoic acid, whereas the 7α‐hydroxylation of cholesterol and 3β‐hydroxy‐5‐cholenoic acid was low.

Variability in the expression of a β2‐microglobulin epitope on hepatocytes in chronic type C hepatitis on treatment with interferon

Luisa García‐Buey, Miguel López‐Botet, Asunción García‐Sánchez, María A. Balboa, José Aramburu, Carmelo García‐Monzón, Agustín Acevedo, Ricardo Moreno‐Otero – 1 March 1993 – Cytotoxic CD8+ T lymphocytes recognize viral antigens in the context of human leukocyte antigen class I molecule coexpression by target cells. Analysis of β2‐microglobulin reactivity is useful in evaluating changes in human leukocyte antigen class I antigen distribution.

Zonal changes of hepatobiliary taurocholate transport in intrahepatic cholestasis induced by 17α‐ethinyl estradiol: A histoautoradiographic study in rats

Hans‐Peter Buscher, Inge Meder, Sabine Macnelly, Wolfgang Gerok – 1 March 1993 – The liver has a great reserve capacity for hepatobiliary bile salt transport. This study was performed to elucidate the significance of this capacity in ethinyl estradiol–induced cholestasis by direct visualization of the zonal involvement in taurocholate transport. The acinar distribution of [3H]taurocholate was determined by histoautoradiographical study of cryopreserved liver slices in normal rats and rats treated with ethinyl estradiol for 5 days.

Dissection of compartments in rat hepatocytes involved in the intracellular trafficking of high‐density lipoprotein particles or their selectively internalized cholesteryl esters

Stefan Jäckle, Franz Rinninger, Thomas Lorenzen, Heiner Greten, Eberhard Windler – 1 March 1993 – The trafficking of apolipoprotein E–deficient highdensity lipoprotein particles and of their component cholesteryl esters in rat hepatocytes was studied. Human high‐density lipoprotein 3, labeled with two nondegradable, intracellularly trapped tracers in their apolipoprotein A–I and their cholesteryl esters, were injected into rats, and five subcellular hepatocytic fractions were isolated at various time intervals.

Effects of dietary cholesterol on bile formation and hepatic processing of chylomicron remnant cholesterol in the rat

Martin J. Smit, Folkert Kuipers, Roel J. Vonk, Arno M. Temmerman, Stefan Jäckle, Eberhard E. T. Windler – 1 March 1993 – We have studied the coupling between hepatic uptake of chylomicron remnant cholesteryl ester and biliary excretion of cholesterol and bile acids in rats, after feeding them a cholesterol‐free (control) or a high‐cholesterol diet (1% wt/wt) for 2 wk. We equipped rats with permanent catheters in the bile duct, duodenum and heart to allow experiments in unanesthetized, unrestrained animals.

Accumulation of organic anion in intracellular vesicles of cultured rat hepatocytes is mediated by the canalicular multispecific organic anion transporter

Ronald P. J. Oude Elferink, Conny T. M. Bakker, Han Roelofsen, Esther Middelkoop, Roelof Ottenhoff, Marc Heijn, Peter L. M. Jansen – 1 March 1993 – Transport of organic anions within hepatocytes and the possible involvement of intracellular vesicles were studied with fluorescence microscopy. For this purpose monochlorobimane, a nonfluorescent hydrophobic compound that readily permeates into cells and is conjugated with glutathione to form the fluorescent glutathione bimane, was used. In the isolated perfused livers of normal rats, glutathione bimane is rapidly secreted into bile.

Hemodynamic and humoral changes after liver transplantation in patients with cirrhosis

Miquel Navasa, Faust Feu, Joan Carles García‐Pagan, Wladimiro Jiménez, Josep Llach, Antoni Rimola, Jaume Bosch, Joan Rodés – 1 March 1993 – Splanchnic and systemic hemodynamics and plasma levels of aldosterone, glucagon and plasma renin were investigated in 12 patients with advanced cirrhosis before and 2 wk (14.6 ± 2.8 days) and 2 mo (60.8 ± 10.5 days) after orthotopic liver transplantation. Liver transplant was followed by significant (p < 0.01) changes in systemic hemodynamics at 2 wk, with a marked reduction in cardiac index (4.9 ± 0.8 vs.

Is vesicular exocytosis and membrane recycling a mechanism for secretin‐induced choleresis in bile duct epithelium?

Jorge J. Gumucio, Won Kyoo Cho, James L. Broder – 1 March 1993 – Intrahepatic bile duct epithelial cells, or cholangiocytes, contribute to bile secretion in response to hormones, including secretin. However, the mechanism by which secretin stimulates ductular bile flow is unknown. Since recent data in nonhepatic epithelia have suggested a role for exocytosis in fluid secretion, we tested the hypothesis that secretin stimulates exocytosis by isolated cholangiocytes.

Subscribe to