• Proceedings of the Korean Aquaculture Society Conference
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• 2001.12a
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• pp.228-229
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• 2001

• Fisheries and Aquatic Sciences
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• v.5 no.4
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• pp.251-257
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• 2002

Effects of bisphenol-A (BPA) on vitellogenin (VTG) synthesis and estrogen-estrogen receptor $(E_2- ER)$ binding activity were examined in primary hepatocyte cultures of rainbow trout, Oncorhynchus mykiss. Hepatocytes were precultured for 2 days and then $estradiol-17\beta\;(E_2,\;2\times10^{-6}M)\;BPA\;(10^{-5}-10^{-8}M)$ and/or 4-hydroxy-tamoxifen $(4-OHT,\;10^{-6} M)$ were simultaneously added to the incubation medium. Hepatocytes were cultured for 5 more days and then spent medium was analyzed by SDS-PAGE for VTG production. The addition of BPA to the incubation medium had no effect on the viability of hepatocytes in the culture. On the other hand, BPA increased VTG production in a concentration-dependent way and a significant increment occurred at BPA concentrations greater than $10^{-6}$M. Although VTG was increased by the addition of $E_2\;(2\times10^{-6}\;M)\;or\;BPA\;(10^{-5}M)$, its were reduced by a simultaneous 4-OHT $(10^{-6}\;M)$ addition. BPA inhibited $E_2-human$ ER binding activity by $72\%$ at $10^{-5}$ M of BPA. These results suggested that BPA induced VTG synthesis by BPA-ER binding activity in the hepatocyte of rainbow trout.

• Toxicological Research
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• v.16 no.2
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• pp.125-131
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• 2000

The ethanol extract of Rhus verniciflua Stokes (RVS), the Korean Lacquer tree, was subsequentely isolated and fractioned into two portions using distilled water (SED) and 99% ethanol (SEE) as elution buffers through silica gel column (4x28 em, 22 $\AA$. 28~200 mesh). To know the antioxidative effect of the RVS extracts, primary hepatocytes were exposed to hydroxyl radical generated by 20 mU/$m\ell$ glucose oxidase with SED or SEE for 4 hr. The addition of 100$\mu\textrm{g}$/$m\ell$ SED in culture medium showed good protection from glucose oxidase (GO)-mediated cytotoxicity of hepatocytes, showing approximately equivalent to control. When the hepatocytes were incubated with 100 $\mu\textrm{g}$/$m\ell$ SED or SEE only for 4 hr. the activities of cell-associated superoxide dismutase (SOD) and catalase were elevated up to 1.22 fold and 1.4 fold, respectively, compared to control. Further increase, 1.88fold in SOD activity or 1.64fold in catalase activity, was also observed when the hepatocytes were incubated with 100 units/$m\ell$ of commercial SOD or catalase for 4 hr. Moreover. the glucose oxidase-mediated cytotoxicity in cultured hepatocytes was generally reduced upon addition of lysate obtained from SED or SEE-stimulated hepatocytes in a dose-dependent manner. From these results, we suggest that, in cultured hepatocytes, RVS ethanol extract can efficiently reduce cytotoxicity induced by glucose oxidase and may increase the activity of cell-associated SOD and/or catalase, thereby preventing and/or scavenging superoxides and hydroxyl radicals in this experiment.

• Fisheries and Aquatic Sciences
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• v.1 no.1
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• pp.19-23
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• 1998

Effects of pituitary and thyroid hormones on estradiol-induced vitellogenin (VTG) induction were electrophoretically examined in primary hepatocyte cultures of rainbow trout. Hepatocytes were precultured for 2 days and then estradiol-17 $\beta$ $(E_2,\;2 \times 10^{-6}M)$>, triiodothyronine $(T_3,\;10^{-8}-10^{-6}M)$, bovine growth hormone (bGH, 10-100 ng/ml), ovine prolactin (oPRL, 100-500 ng/ml), and pituitary extract (PE) of rainbow trout (0.75PE/dish) were added to the incubation medium. The hepatocytes were cultured for 7 more days. The addition of oPRL to the incubation medium was not effective in increasing VTG production at any concentrations. The addition of PE to the incubation medium with $E_2$ was not effective in increasing VTG production. The addition of bGH to the incubation medium with $E_2$ was not effective in increasing the rate of VTG production at concentrations of 10-50 ng/ml. However, a higher concentration of bGH, 100 ng/ml, increased VTG production. The various concentrations of $T_3$ were ineffective in stimulating VTG production. These results suggest that GH could be one of stimulus factors for VTG production in rainbow trout.

• Fisheries and Aquatic Sciences
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• v.4 no.4
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• pp.180-185
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• 2001

Al and Cd-induced inhibition of vitellogenin (VTG) production was examined at the estrogen receptor (ER) level in rainbow trout Oncorhynchus mykiss hepatocytes. The binding of $[^3H]$ $estradiol-17\beta\;(E_2)$ to hepatocytes reached a plateau 3 days after addition of $E_2\;(2\times\;10^{-6} M)$to the medium. The binding activity was linearly reduced with the increased concentrations $(-10^{-5}\;M)$ of 4-hydroxy-tamoxifen (4-OHT) and specific binding linearly increased with the increased doses of $[^3H]\;E_2$, indicating that the radioligand bound to ER. Al $(-10^{-4}\;M)$and Cd $(10^{-6}\;M)$ as well as 4-OHT $(10^{-6}\;M)$ significantly reduced the $[^3H]\;E_2$-binding activity by $30­40\%$, while they completely inhibited VTG production. Al and Cd had no effect on $E_2-human$ $ER\alpha$ binding activity at any concentrations used $(-10^5\;nM\;each)$. These results suggested that Al and Cd inhibited VTG production in part by interfereing with the ER level. Inhibitory effects of these metals on the $E_z-dependent$ upregulation of ER activity are also discussed.

• Environmental Mutagens and Carcinogens
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• v.7 no.2
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• pp.59-64
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• 1987

Cytotoxic and genotoxic potential of monosodium glutamate (MSG) were evaluated in primary cultures of rat hepatocytes. When exposed to liver cell culture continuously for 24 hr, MSG did not show any cytotoxic effects up to 0.5% (w/v) level as determined by Tryphan Blue exclusion and lactic dehydrogenase release test. MSG also did not induce unscheduled DNA synthesis or DNA single-strand breaks in hepatocyte cultures up to 1% level. No synergistic effects of MSG were observed on aflatoxin B$_1$-induced DNA damage when 1% MSG was treated to liver cell culture along with aflatoxin B$_1$.

• Environmental Analysis Health and Toxicology
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• v.22 no.3
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• pp.227-233
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• 2007

It has been reported that hepatic glutathione (GSH) levels are decreased in diabetic patients, and glucagon increases hepatic efflux of GSH into blood. The signaling pathways responsible for mediating the glucagon effects on GSH efflux, however, are unknown. The signaling pathways involved in the regulation of GSH efflux in response to glucagon and insulin were examined in primary cultured rat hepatocytes. The GSH concentrations in the culture medium were markedly increased by the addition of glucagon, although cellular GSH levels are significantly decreased by glucagon. Insulin was also increased the GSH concentrations in the culture medium, but which is reflected in elevations of both cellular GSH and protein. Treatment of cells with 8-bromo-cAMP or dibutyryl-cAMP also resulted in elevation of the GSH concentrations in the culture medium. Pretreatment with H89, a selective inhibitor of protein kinase A, before glucagon addition markedly attenuated the glucagon effect. These results suggest that glucagon changes GSH homeostasis via elevation of GSH efflux, which may be responsible for decrease in hepatic GSH levels observed in diabetic condition. Furthermore, the present study implicates cAMP and protein kinase A in mediating the effect of glucagon on GSH efflux in primary cultured rat hepatocytes.

• Journal of Biomedical Engineering Research
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• v.19 no.3
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• pp.215-224
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• 1998

This paper is fundamental study to develope the extracorporeal liver support system for patient with fulminant hepatic failure(FHF) or being expected for orthotopic liver transplantation. The polyurethane foam, which is composed of the density of 33kg/m3, the average pore diameter of 500${\mu}{\textrm}{m}$, the closed window of 60-70%, was manufactured with the prepolymer of 15% NCO-, Hepatocytes were inoculated to form spheroids in polyurethane foam. The time of spheroid formation in BSA(Bovine Serum Albumin) coated polyurethane foam was shorter than that in raw polyurethane foam. To verify the function of hepatocyte spheroids, we measured ammonia removal rate, urea and albumin secretion rate. Polyurethane foam was suitable for culture of hepatocyte spheroids. And culture of hepatocyte spheroids in polyurethane foam has high possibility in using as an extracorporeal liver support system.

• Toxicological Research
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• v.7 no.2
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• pp.239-255
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• 1991

Several types of IFNs were tested for their ability to suppress TCDD-inducible P-450 dependent mixed function oxidase (MFO) system in mouse primary hepatocytes. Mouse IFN-gamma (IFN-G) markedly suppressed EROD activity when added at the same time as TCDD (10 nM). The antagonism of EROD activity by IFN-G exhibited both a dose-(10-100 U/ml) and time-depedence. In contrast, mouse IFN-A/B was only moderately suppressive and only at high concentrations (500 U/ml). Rat IFN-G was even more selective than mouse, wherase human IFN-G had no activity.

• Toxicological Research
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• v.23 no.4
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• pp.301-309
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• 2007

Paecilomyces tenuipes (PT), one of the Ascomycetes family, has been used for medicinal purposes due to its broad pharmacological activities. The present study was undertaken to investigate the hepatoprotective effects of PT water extracts against $CCl_4$-induced hepatotoxicity in primary cultures of adult rat hepatocytes. When the extract of PT was directly added into the culture medium at 1, 2, and 5 mg/ml, the extracts not only reduce the $CCl_4$-induced elevation of aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase, and lipid peroxide, but also protect cultured hepatocytes from $CCl_4$-induced reduction of reduced glutathione, glutathione reductase, glutathione-S-transferase, glutathione peroxidase, catalase and superoxide dismutase. In addition, the effects of PT water extracts on cytochrome P450 enzymes were relatively marginal, indicating that the hepatoprotective effects of PT extract against $CCl_4$-induced toxicity might not be due to the inhibition of $CCl_4$ activation. In conclusion, the PT extracts were effective in protecting against $CCl_4$ induced hepatotoxicity in hepatocyte cultures, at least in part, by scavenging free radicals, and by modulating enzyme systems involved in cellular oxidative stress.