• Fisheries and Aquatic Sciences
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• v.4 no.4
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• pp.186-191
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• 2001

Vitellogenin (VTG) and VTG mRNA induction by $estradiol-17\beta\;(E_2)$ were examined in the primary cultures of hepatocyte in the rainbow trout. Hepatocytes were precultured for 2 days, then $E_2$ was added and cultured for another 5 days. Media and hepatocytes were then analyzed by electrophoresis and Northern blotting for VTG and VTG mRNA, respectively. The hepatocytes were formed a few aggregates within 5 days without further spreading to a monolayer. Cell viability and high DNA content were maintained during the incubation. The hepatocyte culture with E2 induced a weak VTG band at a molecular weight of 175kDa on Day 2 after $E_2$ addition. The relative amount of VTG was expressed in percentage of total protein concentrations. VTG was gradually increased as $1.9\%$ on Day 2, $6.3\%$ on Day 4 and $7.3\%$ on Day 5. VTG mRNA band was detected at about 6.6 kb in the culture with $E_2$ at day 1 of culture. The level of VTG mRNA expression linearly increased with time until Day 5 (r=0.97).

• Fisheries and Aquatic Sciences
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• v.1 no.1
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• pp.24-29
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• 1998

Effect of extracellular calcium in vitellogenin (VTG) production in response to estradiol-17 $\beta$ $(E_2,\;2\times10^{-6}M)$ was examined in primary hepatocyte culture of rainbow trout, Onchorhynchus mykiss. Total calcium in estrogenized sera significantly increased, compared with the control, while diffusible calcium was insignificant. However, diffusible calcium in the incubation medium with $E_2$ was significantly reduced, compared with the control. The uptake of extracellular calcium by cultured hepatocytes signifIcantly increased 90 min after $E_2$ addition. Moreover, the accumulation of intracellular calcium increased in the cultures with $E_2$, regardless of the calcium concentrations in the incubation media. In addition, $E_2-primed $ VTG production was significantly decreased by withdrawal of E_2$ from the incubation medium. Moreover, VTG production by $E_2-primed$ hepatocytes was reduced by removing calcium from the incubation medium with or without $E_2$. These results suggest that the entry of extracellular calcium into the cytoplasm is an important step for VTG production in primary hepatocyte cultures in rainbow trout.

• 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.8 no.1
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• pp.9-15
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• 1992

Hydroxybrazilin was examined for its effects on glycogen synthesis in primary cultured rat hepatocytes. At 10-6 M hydroxybrazilin, glycogen synthesis was increased in basal state, but not in insulin stimulated state. However, any signiFicant changes were nor observed at 10-5 M hydroxybrazilin in both states. The glycogen synthesis was rather suppressed at 10-5M hydroxybrazilin. It was also observed that hydroxybrazilin increased insulin sensitivity but not insulin responsiveness at 10-5M concentration. These results suggest that hydroxybrazilin might exert hypoglycemic action through its effects on insulin receptor and post receptor events.

• Archives of Pharmacal Research
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• v.13 no.4
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• pp.355-358
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• 1990

In order to investigate the cellular mechanisms of hypoglycemic of brazilin, hepatocyte monolayer culture was introduced and, glycogen synthesis rate and insulin binding were measured as parameters. Glycogen synthesis and insulin sensitivity were remarkably augmented by the treatment of brazilin. Brazilin slightely increased insulin binding. Scatchard analysis revealed that this increase in insulin binding was not due to increase in the binding capacity but in binding affinity. These results suggest that the augmentation of hepatic glycogenesis and insulin sensitivity by brazilin may play an important role in the improvement of hyperglycemia.

• YAKHAK HOEJI
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• v.37 no.5
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• pp.499-503
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• 1993

Betaine, a major component of Lycii Fructus, was evaluated for its anti-hepatotoxic activity on carbon tetrachloride-induced hepatotoxicity in primary cultured rat hepatocytes. Betaine was found to attenuate carbon tetrachloride-induced hepatotoxicity both morphologically and biochemically. Typical hepatocyte necrosis due to carbon tetrachloride seemed to be reduced by 50 to 500 $\mu{M}$ of betaine under microscopical observation. The value of glutamic pyruvic transaminase released from the hepatocytes into the medium significantly decreased as betaine concentration increased. Betaine also significantly elevated the reduced activities of some enzymes, cytochrome P-450, 7-ethoxycoumarin-0-deethylase and glutathione-S-transferase, involved in xenobiotic metabolism due to carbon tetrachloride-induced hepatotoxicity. These results demonstrate a possible hepato-protective role of betaine against fatty liver that could be easily induced by carbon tetrachloride.

• Animal Bioscience
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• v.35 no.11
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• pp.1787-1799
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• 2022

Objective: Choline deficiency, one main trigger for nonalcoholic fatty liver disease (NAFLD), is closely related to lipid metabolism disorder. Previous study in a choline-deficient model has largely focused on gene expression rather than gene structure, especially sparse are studies regarding to alternative splicing (AS). In modern life science research, primary hepatocytes culture technology facilitates such studies, which can accurately imitate liver activity in vitro and show unique superiority. Whereas limitations to traditional hepatocytes culture technology exist in terms of efficiency and operability. This study pursued an optimization culture method for duck primary hepatocytes to explore AS in choline-deficient model. Methods: We performed an optimization culture method for duck primary hepatocytes with multi-step digestion procedure from Pekin duck embryos. Subsequently a NAFLD model was constructed with choline-free medium. RNA-seq and further analysis by rMATS were performed to identify AS events alterations in choline-deficency duck primary hepatocytes. Results: The results showed E13 (embryonic day 13) to E15 is suitable to obtain hepatocytes, and the viability reached over 95% by trypan blue exclusion assay. Primary hepatocyte retained their biological function as well identified by Periodic Acid-Schiff staining method and Glucose-6-phosphate dehydrogenase activity assay, respectively. Meanwhile, genes of alb and afp and specific protein of albumin were detected to verify cultured hepatocytes. Immunofluorescence was used to evaluate purity of hepatocytes, presenting up to 90%. On this base, choline-deficient model was constructed and displayed significantly increase of intracellular triglyceride and cholesterol as reported previously. Intriguingly, our data suggested that AS events in choline-deficient model were implicated in pivotal biological processes as an aberrant transcriptional regulator, of which 16 genes were involved in lipid metabolism and highly enriched in glycerophospholipid metabolism. Conclusion: An effective and rapid protocol for obtaining duck primary hepatocytes was established, by which our findings manifested choline deficiency could induce the accumulation of lipid and result in aberrant AS events in hepatocytes, providing a novel insight into various AS in the metabolism role of choline.

• YAKHAK HOEJI
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• v.52 no.1
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• pp.56-61
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• 2008

The hepatoprotective effects of the water extracts of Hovenia dulcis Thunb (HD) were investigated in vitro. Following the induction of hepatotoxicity by ethanol in primary cultures of rat hepatocytes, the protective effects of four different water extracts of HD were determined through serial dose-response and time-dependent studies. The individual extracts used in these studies were prepared from fruits, seeds, leaves and tubes. Treatment of hepatocyte cultures with the water extracts of HD provided a significant protection from the increased lactate dehydrogenase activity induced by ethanol. Particularly, the fruits extract was the most effective against ethanol-induced hepatotoxicity in the primary cultures of rat hepatocytes. The results demonstrated that the extracts might have the protective effect against ethanol-induced toxicity in hepatocyte cultures.

• Fisheries and Aquatic Sciences
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• v.2 no.1
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• pp.85-92
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• 1999

We examined the expression patterns of heat shock proteins in primary cultured hepatocytes from flounder (Paralichthys olivaceus) exposed to heat shock. The expression of hsp90, hsp70, hsp40, hsp30, and hsp27 was induced and major polypeptides were hsp70, hsp30 and hsp27. Northern blot analysis showed that expression of hsp70 was inhibited by transcriptional inhibitor actinomycin D, suggesting that expression of hsp70 gene is regulated at the transcriptional level. Prolonged exposure of cells to an elevated incubation temperature $(30^{\circ}C)$ induced the transient synthesis of hsp90, hsp70, hsp40, and hsp30 whereas maintenance of cells at a slightly higher incubation temperature $(32^{\circ}C)$ induced the continuous syntheses of these hsps. When cells were incubated at a higher temperatures $(35^{\circ}C\;or\;37^{\circ}C)$, the synthesis of hsps was almost similar to that of hsps in cells exposed to 32't except for the induction of hsp27 synthesis. These results that temperature and incubation time for optimum expression of each hsp during prolonged heat shock are different.

• Korean Journal of Veterinary Research
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• v.46 no.4
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• pp.315-322
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• 2006

Ethanol abuse is associated with liver injury, neurotoxicity, modulation of immune responses, and increased risk for cancer, whereas moderate ethanol consumption exerts protective effects against liver injury. However, the underlying signal transduction mechanisms of insulin-like growth factors (IGFs) which play an important regulatory role in various metabolism mechanisms are not well understood. We investigated the effects of ethanol-induced p42/44 activity on IGF-I secretion, IGF-I receptor and IGFBP-1 secretion using radioimmunoassay and western blotting in primary cultured rat hepatocytes. The p42/44 activity, IGF-I secretion and IGF-I receptor activity significantly accelerated compared to control at 10 and 30 min after 200 mM ethanol treatment, but then it became suppressed at 180 min. In contrast, IGFBP-1 secretion was inhibited compared to control at 30 min after 200 mM ethanol treatment, but increased at 180 min. The IGF-I secretion, IGF-I receptor and p42/44 activity at 30 min after 200 mM ethanol treatment accelerated with increasing ethanol concentration but IGFBP-1 secretion inhibited (p<0.05). The increased IGF-I secretion, inhibited IGFBP-1 secretion and IGF-IR activity by ethanol-induced temporal p42/44 activity at 30 min after ethanol treatment was blocked by treatment with PD98059. Alcohol dehydrogenase (ADH) inhibitor, 4-methylpyramazole blocked the changes of IGF-I secretion, IGFBP-1 secretion, and IGF-IR activity by ethanol-induced p42/44 activity at 30 and 180 min. Taken together, these results suggest that ethanol is involved in the modulation of IGF-I and IGFBP-1 secretion and IGF-IR activity by p42/44 activity in primary cultured rat hepatocytes. In addition, changing of p42/44 activity by ethanol was caused with ADH.