• Polymer(Korea)
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• v.32 no.2
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• pp.131-137
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• 2008

We have fabricated polystyrene (PS) nanofibrous scaffold for hepatocyte culture by electrospinning method and subsequently coated with specific ligand of Poly[N-p-vinylbenzyl-O-$\beta$-D-galactopyranocyl-($1{\rightarrow}4$)-D-gluconamide](PVLA) to enhance hepatocytes attachment. Rat hepatocytes behavior on the PVLA-coated and non-coated PS nanofibrous matrices have been investigated. Electrospun PS nanofiber structures revealed randomly aligned fibers with average diameter of 500 nm. It is observed that PS nanofibrous matrix could incorporate many cells into the interior of the matrix probably due to the suitable pore size. Cell viabilities cultured on PVLA-coated PS nanofibrous mats were maintained for 3 weeks, while it was decreased rapidly on PVLA-coated PS dishes. High hepatic functions especially for albumin secretion and ammonia removal were maintained at least for 2 weeks on nanofibrous mats but rapidly decreased on flat PS dishes. These results indicate that nanofibrous structure enabled 3-D culture with high level of cell-cell contact results in providing cell-cell communications and subsequent long-term maintenance of specific cell functions.

• Investigative Magnetic Resonance Imaging
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• v.2 no.1
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• pp.73-82
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• 1998

Purpose : A precise NMR technique for measuring the rate of water exchange and cell membrane permeability across the hepatocyte membrane using liver-specific MR contrast agent is described. Materials and Methods : The rat hepatocytes isolated by perfusion of the livers were used for the NMR measurements. All experiments were performed on an IBM field cycling relaxometer operating from 0.02MHz to 60 MHz proton Larmor frequency. spin-echo pulse sequence was empolyed to measure spin-lattice relaxation time, T1. The continuous distribution analysis of water proton T1 data from rat hepatocytes containing low concentrations of the liver specific contrast agent, Gd-EOB-DTPA, modeled by a general two compartment exchange model. Results : The mean residence time of water molecule inside the hepatocyte was approximately 250 msec. The lower limit for the permeability of the hepatocyte membrane was $(1.3{\pm}0.1){\;}{\times}{\;}10^{-3}cm/sec$. The CONTIN analysis, which seeks the natural distribution of relaxation times, reveals direct evidence of the effect of diffusive exchange. the diffusive water exchange is not small in the intracellular space in the case of hepatocytes. Conclusions : Gd-EOB-DTPA, when combined with continuous distribution analysis, provides a robust method to study water exchange and membrane permeability in hepatocytes. Water exchange in hepatocyte is much slower thatn that in red blood cells. Therefore, tissue-specific contrast agent may be used as a functional agent to give physiological information such as cell membrane permeability.

• The Korean Journal of Zoology
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• v.34 no.3
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• pp.403-409
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• 1991

화학적 암 유발물인 diethylnitrosamine(DENA) 연여로 야기되는 흰쥐 (Sprague Dawley) 간세포의 변화 양상을 전자현미경과 silver염색방법으로 관찰하였다. DENA는 간세포내의 핵, 미토콘드리아, 담즙관에 뚜렷한 형태적 변화를 일으켰으며 인(nucleolus)의 크기와 수도 증가하였다. 또한 정상세포보다 인 (nucleolus) 부위의 염색 정도도 강하였는데 이것은 silver granule이 서로 연결되어 망상구조를 형성하기 때문인 것으로 생각되며 이들 망상구조는 순수한 rDNA부분과 핵내 단백질이 인내에서 서로 엉킨어 나타나는 현상일 것으로 사료된다. 또한 DENA투여 켤과 나타난 인의 크기와 인부위의 수적 증가현상의 결과로 rRNA 합성물의 변화를 유추할 수 있었다.

• Korean Journal of Environmental Agriculture
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• v.24 no.2
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• pp.146-152
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• 2005

The objective of present study was to investigate the effect of onion extracts on mercuryinduced cytotoxicity, lipid peroxidation and antioxidant enzyme activities in primary monolayer cultures of rat hepatocytes. Primary cultures of rat hepatocytes were incubated for 6 hr in the presence of various concentrations (0, 1, 5, 10, 30 or 50 ppm) of $HgCl_2$. Cytotoxicity and cell viability were determined by measuring glutamic oxaloacetic transaminase (GOT) activity, lactate dehydrogenase (LDH) activity and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) value. Lipid peroxidation w as evaluated using thiobarbituric acid reactive substances (TBARS) assay. Effects of onion extract on antioxidant system were determined by measuring catalase, glutathione peroxidase (GSH-Px), glutathione reductase (GSH-Rd) activities as well as DPPH free radical scavenging activity. $HgCl_2$ at the concentration of 10 ppm increased GOT activity and TBARS concentration but decreased %MTT reduction, whereas $HgCl_2$ at the concentration of 30 ppm increased LDH activity, representing that $HgCl_2$ caused cytotoxicity and lipid peroxidation in dose-dependent manner, $HgCl_2$ at the concentration of 30 ppm significantly decreased catalase, GSH-Px and GSH-Rd activities. When primary cultures of rat hepatocytes were incubated with various concentrations (0, 0.01, 0.05, 0.1 or 0.3 mg/ml) of onion extract for 6 hr in the presence of 30 ppm of $HgCl_2$, onion extracts at the concentration of 0.05 mg/ml decreased GOT activity, but increased %MTT reduction by 30 ppm of $HgCl_2$. $HgCl_2-induced$ LDH activity and TBARS concentration were decreased by onion extract at the concentration of 0.01 mg/ml. Taken together, onion extract prevented H$HgCl_2-induced$ hepatocyte injury and lipid peroxidation. Onion extracts at the concentration of 0.1 mg/ml almost or completely inhibited $HgCl_2-induced$ catalase and GSB-Px activities. GSH-Rd activity, however, was not affected by onion extract. Free radical scavengjing activity was increased as concentration of onion extract increased. Onion extract at the concentrion of 5 mg/ml possesed mote than 93% scavenging activity comparing to 100% radical scavenging activity by pyrogallol solution as a reference. These results demonstrate that onion extracts suppressed mercury-induced cytoctoxicity and lipid peroxidation by scavenging free radical and increasing catalase and GSH-Px activities.

• Journal of Life Science
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• v.19 no.8
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• pp.1119-1124
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• 2009

Hyperlipidemia has been reported to be associated with the development of fatty liver. Palmitic acid, a major saturated fatty acid, is involved in the development of diverse diseases. The activation of mitogen activated protein kinases (MAPKs), such as Jun N-terminal kinase (INKs) and p38 MAPK is implicated in the apoptosis in diverse cells. Thus, this study was conducted to investigate the effects of palmitic acid on apoptosis and its relationship between JNK and p38 MAPK in cultured rat hepatocytes. In the present study, palmitic acid (>50 uM) decreased cell proliferation and increased lactate dehydrogenase activity in hepatocytes, which was blocked by the treatment of SP600125 (a JNK inhibitor) and SB203580 (a p38 MAPK inhibitor). Indeed, palmitic acid decreased Bcl-2 expression but increased Bax expression in rat hepatocytes, which was blocked by the treatment of SP600125 and SB203580. In addition, palmitic acid decreased glutathione (GSH) content and increased lipid peroxide formation, which was blocked by the treatment of SP600125 and SB203580. Western immunoblotting analysis also revealed that palmitic acid increased JNK and p38 MAPK. In conclusion, palmitic acid induced apoptosis through oxidative stress via JNK and p38 MAPK activation in rat hepatocytes.

• Applied Biological Chemistry
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• v.49 no.3
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• pp.233-237
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• 2006

In the present study, we compared the functional analysis of pear extracts cultured in conventional and environment-friendly conditions in primary cultured rat hepatocytes. ATP synthesis significantly increased by the treatment with environment friendly cultured pear powder but not by conventional group. In addition, cell proliferation using $[^3H]$-thymidine incorporation was also stimulated by environment-friendly cultured pear extract compared to conventional group. Moreover, the expressions of CDK-2 and CDK-4 were increased but p21WAF1/Cip1 and p27 Kip1 decreased by environment-friendly cultured pear extract but not by conventional group. In conclusion, environment-friendly cultured pear powder has stimulatory effect on cell proliferation compared to conventional group in primary cultured rat hepatocytes.

• Journal of Life Science
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• v.31 no.2
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• pp.223-228
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• 2021

Cyclophosphamide (CP) is widely used in cancer and lymphoma treatments and as an immunosuppressant drug. CP is a DNA alkylating agent that metabolizes into 4-hydrocyclophosphamide (4H-CYP) and aldophosphamide in hepatocytes. However, its metabolites cause DNA synthesis disorder, leading to apoptosis and toxic side effects. The development of technology to minimize this side effect is essential to improve CP's clinical application. Various bioactive compounds have been reported to have anti-cancer and antioxidant functions and preventive or therapeutic roles in metabolic diseases. Many researchers have attempted to minimize the side effects and improve the efficacy of these drugs together with the use of bioactive compounds. Ulmus macrocarpa Hance has been used for the treatment of edema, mastitis, stomach pain, tumors, cystitis, and other inflammatory diseases. The aim of this study was to investigate at the histological level the protective function of U. macrocarpa Hance against CP's side effects and any potential toxic effect of U. macrocarpa Hance in the liver and kidney. Water extracts of U. macrocarpa Hance reduced CP-induced toxicity and did not induce any histological damage in the liver and kidney. Therefore, U. macrocarpa Hance would be applicable in the pharmaceutical industry.

• Journal of Digestive Cancer Research
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• v.4 no.1
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• pp.21-28
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• 2016

Hepatocellular carcinoma (HCC) is rather unique. Most of HCC patients have underlying chronic liver diseases with or without cirrhosis and the prognosis of HCC depends on the liver function, as well as the tumor extent. Non-invasive diagnosis of HCC can be made with certain risk factors and specific imaging findings (e.g. hypervascularity). Patients with HCC can receive surgical resection, radiotherapy, and systemic chemotherapy as other solid malignancies. HCC has more treatment options such as liver transplantation, transarterial chemoembolization (TACE) and radiofrequency ablation (RFA). A variety of practice guidelines for HCC has been published by many academic societies. Different healthcare systems and availability of resources also affect the practice guidelines; therefore, practice guidelines have similarities and dissimilarities. Herein, we review the current status of practice guidelines for HCC and future perspectives for the improvement of guidelines are also discussed.

• Journal of Aquaculture
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• v.11 no.2
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• pp.241-248
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• 1998

Effects of A23187 on estradiol$-17^{\beta}$-induced vitellogenin (VTG) induction were electrophore-tically examined in primary hepatocyte cultures in rainbow trout. hepatocytes were predultured for 2 days and then estradiol-$17^{\beta}$(E2, $2{\times}10^{-6}$M) and calcium ionophore (A23187, $10^{-7)$~$10^{-5}$ M) were added to the incubation medium. The hepatocytes were cultured for 7 more days. In addition, effects of A23187 on $E_2$-primed VTG production were investigated for 7 days. The addition of A23187 ($10^{-7)$~$10^{-5}$M) to the incubation medium specifically reduced VTG production by hepatocytes in a concentration-dependent way. The addition of A23187 significantly reduced the rate of $E_2$-primed VTG production to 18% of the control (E2 only) on Day 7. However, $E_2$-primed VTG production was reduced to 47% of the control by withdrawal of $E_2$ from the incubation medium. Therefore, these results suggest that intracellualr sequestered calcium could regulate VTG synthesis at the translational and/or post-translational stage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.2
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• pp.158-161
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• 2005

We have isolated fractions from Cordyceps militaris and Paecilomyces japonica and investigated their effects on the activity of rat liver cytosolic glucokinase, a key metabolic enzyme involved in carbohydrate metabolism. The dried powder of the C. militaris and P. japonica were successively extracted with ethanol and with 70% ethanol. The residue was exhaustively extracted with hot water. The extract was dialyzed against water, and to the non-dialyzable solution was added 2 volumes of ethanol. The precipitate was collected by centrifugation dispered in water, and lyophilized to afford fraction A. The residue after hot-water extraction was suspended in 5% sodium carbonate. The final residue was suspended in 5% NaOH. The alkaline suspension was purified in a similar manner as described above to afford fraction B. Hepatic glucokinase activities of the fraction A extracted from C. militaris and P. japonica were 371.4 and 379%, respectively. The fraction B was 314.2 and 147.4%. The activity of fraction B of C. militaris extracts was higher than that of P. japonica. Liver cytosolic glucokinase activity of rats fed normal diet supplemented with 0.1% C. militaris was 1316%. In conclusion, the present study has demonstrated that C. militaris extracts were able to prevent sudden postprandial peaks in blood glucose as a result of a marked increase in the liver cytosolic glucokinase activities.