Menadione and cumene hydroperoxide induced cytotoxicity in biliary epithelial cells isolated from rat liver

Parola, Maurizio; Kh, Cheeseman; Biocca, Maria E.; Mu, Dianzani; Tf, Slater

doi:10.1016/0006-2952(90)90118-5

Cited by 20 publications

(6 citation statements)

References 31 publications

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“…This could be protective in cells that have a glutathione content that is only one third of the one present in hepatocytes. 35 Overexpression in Xenopus laevis oocytes of IP 3 R type 3 increased influx of extracellular Ca 2ϩ , 36 and IP 3 R 3 has been suggested to play a role in store-operated or capacitative Ca 2ϩ entry. 36,37 In lymphocytes, apoptosis has been causally associated with increased expression of IP 3 R type 3 at the plasma membrane.…”

Section: Discussionmentioning

confidence: 99%

Expression of inositol 1,4,5-trisphosphate receptor isoforms in rat cirrhosis

et al. 1999

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Ca 2؉ signals mediate the hepatic effects of numerous hormones and growth factors. Hepatic Ca 2؉ signals are elicited by the inositol trisphosphate receptor, an intracellular Ca 2؉ channel. Three isoforms of this receptor have been identified; they are expressed and regulated differently. We investigated the effect of liver fibrosis and cirrhosis on the hepatic expression of the inositol trisphosphate receptor isoforms. Two different rat models were used: bile duct ligation (fibrosis) and chronic exposure to CCl 4 /phenobarbital (cirrhosis). Messenger RNA levels were determined by ribonuclease protection assay (RPA), competitive polymerase chain reaction (PCR) followed by Southern blotting, and real-time quantitative PCR. Protein expression was assessed by Western blotting; tissue distribution was assessed by immunohistology. In control animals, isoform 2 was the predominant isoform, isoform 1 represented less than one third, and isoform 3 less than 1%. After bile duct ligation, expression of types 1 and 3 increased 1.9-and 5.7-fold, and expression of type 2 decreased 2.5-fold at the protein level. After exposure to CCl 4 /phenobarbital, expression of types 1, 2, and 3 were 2.4-, 0.9-, and 4.2-fold their expression in control animals. Type 2 was localized to the apical domain of hepatocytes, consistent with a role for Ca 2؉ signals in canalicular function. Type 3 was detectable in intrahepatic bile duct epithelial cells and not in hepatocytes, suggesting that Ca 2؉ signals may be regulated differently in these cells. Signaling through inositol trisphosphate receptor participates in the pathogenesis of cirrhosis, because this process affects the expression of its isoforms. (HEPATOLOGY 1999;30:1018-1026.)Development of cirrhosis implies not only remodeling of the liver architecture, but also dramatic changes in the functions of hepatic cells. These changes are orchestrated by a network of receptors, protein-kinases, and transducers that compose complex signaling pathways. Among them, the inositol 1,4,5-trisphosphate receptor (IP 3 R) plays a central role. 1 Numerous hormones and growth factors bind to receptors on plasma membrane to stimulate the production of inositol 1,4,5-trisphosphate (IP 3 ) and to trigger IP 3 -dependent Ca 2ϩ release through the Ca 2ϩ channel of the IP 3 R. 2 Ca 2ϩ signals regulate many cellular functions from gene expression and cellular division to metabolic pathways and cellular secretion. 1 Both hepatocytes and biliary epithelial cells demonstrate complex Ca 2ϩ signals, which rely essentially on IP 3 R, because the ryanodine receptor, another intracellular Ca 2ϩ channel, could not be detected in liver. 3 In response to hormonal stimulation, intracellular Ca 2ϩ concentration oscillates in hepatocytes and even forms Ca 2ϩ waves through the entire lobule. 4 Hepatocellular Ca 2ϩ signals start in a specific apical location and diffuse in an apical to basal manner. 5 IP 3 -dependent Ca 2ϩ signals stimulate bile canalicular contractions, an effect blocked by nitric oxide. 6 In intrahepatic bil...

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Section: Discussionmentioning

confidence: 99%

Expression of inositol 1,4,5-trisphosphate receptor isoforms in rat cirrhosis

et al. 1999

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“…This was exemplified in this study for the cytotoxic effects of menadione, which have been found to be different in pure cultures of bile duct epithelial cells and of hepatocytes (Parola, 1990) and also in pure cultures of RL-ET-14 cells. To enhance the cytotoxic potential of this compound and to speed up the manifestation of cell death, the cultures had to be pretreated with galactosamine, which is known to exert a number of effects in hepatocytes including inhibition of protein biosynthesis (Bauer et al, 1974).…”

Section: Discussionmentioning

confidence: 99%

Perifusion of co-cultured hepatocytes: optimization of studies on drug metabolism and cytotoxicity in vitro

1996

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The combination of co-cultivation of hepatocytes and epithelial cell lines with a newly developed perifusion system was used for in vitro studies on drug metabolism and cytotoxicity. This approach improved the viability and enhanced the induction of the biotransforming capacity of the hepatocytes. As demonstrated for the induction of 7-ethoxyresorufin O-deethylase activity by 3-methylcholanthrene or benzanthracene, co-cultured hepatocytes in the perifusion system responded more sensitively to these inducers than without perifusion, most likely owing to stable (steady-state) concentrations of the inducers under the former conditions and rapidly declining concentrations under the latter conditions. The perifusion approach rendered it possible to determine the kinetics of drug metabolism during single or sequential incubations. After induction with 3-methylcholanthrene and phenobarbital, phase I metabolism of lonazolac to the monohydroxylated product in perifused co-cultures closely (87%) approached the values reported for the in vivo production, whereas in stationary co-cultures only 52% could be reached. Likewise, cytotoxic effects could be detected more precisely in the perifused co-cultures. If cells were pretreated with 0.2 mmol/L galactosamine for 3 h, perifusion with increasing concentrations of menadione differentially killed epithelial RL-ET-14 cells and hepatocytes at low and high concentrations, respectively, while in stationary co-cultures no differential effect was observed and only the higher concentrations were cytotoxic for both cells. Prevention by incubation with S-adenosylmethionine of menadione cytotoxicity up to a menadione concentration of 250 micromol/L was seen only in the perifused co-cultures, whereas in stationary cultures only a slight shift of the cytotoxic concentration exerting 50% cell damage to higher values was noted. These results demonstrate the versatile application of perifused co-cultures for studies on drug metabolism including induction of cytochrome P450-dependent enzymes and steady-state kinetics of biotransformation, as well as cytotoxic and protective effects of different drugs.

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“…Consequent upon biliary excretion, these metabolites could immediately target the biliary epithelium for injury by depletion of cellular GSH. Moreover, it should be noted that the vulnerability of biliary epithelial cells to GSH depletion is made more pronounced by the fact that this hepatic cell population contains relatively low levels of both GSH and glutathione reductase (47). Indeed, it has been proposed that the biliary pathogenesis of 1-naphthyl isothiocyanate, a structurally analogous carbamoylating agent to MPIC, is linked to its GSH conjugate which acts as a latent form of the isothiocyanate (48).…”

Section: Discussionmentioning

confidence: 99%

Characterization of Novel Isocyanate-Derived Metabolites of the Formamide N-Formylamphetamine with the Combined Use of Electrospray Mass Spectrometry and Stable Isotope Methodology

Borel¹,

Abbott²

1995

Chem. Res. Toxicol.

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Bioactivation of the formamide N-formylamphetamine (NFA) to 1-methyl-2-phenylethyl isocyanate (MPIC) was investigated in rats by screening bile and urine for conjugates subsequent to the phase I event. NFA was administered to rats as a mixture of protio- and pentadeuteriophenyl analogues to gain insight into the carbamoylating activity of MPIC when traced by electrospray liquid chromatography/mass spectrometry (LC/MS). An LC/MS contour generated by recording the summed mass spectrum as a function of chromatographic retention time allowed four biliary metabolites to be identified from four sets of doublets, with the peak of each doublet offset by 5 amu and ca. 0.07 min. Tandem mass spectrometry experiments allowed these metabolites to be attributed structurally to the glutathione, cysteinylglycine, cysteine, and N-acetylcysteine conjugates of the isocyanate MPIC. These assignments were subsequently validated by comparison of the LC/MS properties of the metabolites to synthetic reference compounds. Only the carbamoylated N-acetylcysteine conjugate was detected in urine. The observed excretion in bile of all metabolites of the mercapturate pathway is novel for formamide metabolism. NFA can thus be added to the short list of compounds that are eliminated in this fashion. Factors envisioned as contributory to this metabolic profile in bile include hepatorenal, enterohepatic, and biliary-hepatic cycling, in addition to possible equilibrium exchange of the isocyanate from thiocarbamate conjugates to endogenous free thiols during the course of biliary transit.

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Menadione and cumene hydroperoxide induced cytotoxicity in biliary epithelial cells isolated from rat liver

Cited by 20 publications

References 31 publications

Expression of inositol 1,4,5-trisphosphate receptor isoforms in rat cirrhosis

Expression of inositol 1,4,5-trisphosphate receptor isoforms in rat cirrhosis

Perifusion of co-cultured hepatocytes: optimization of studies on drug metabolism and cytotoxicity in vitro

Characterization of Novel Isocyanate-Derived Metabolites of the Formamide N-Formylamphetamine with the Combined Use of Electrospray Mass Spectrometry and Stable Isotope Methodology

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