• 한국식품영양과학회지
• /
• 제26권6호
• /
• pp.1173-1180
• /
• 1997

Hepatotoxicity of caffeine and acetaminophen was investigated in this study. Special attention was paid to the effect of vitamins on the reduction of hepatotoxicity caused by the chemicals. Rat hepaocytes isolated by two-step perfusion method were cultured in two differents methods-suspension, monolayer cultures-, and exposed to caffeine and/or acetaminophen for 24hrs. Caffeine or acetaminophen exhibited no significant hepatotoxicity in terms of intracellular glutathione(GSH) level and lipid peroxidation(MDA), but GSH level was significantly decreased after administrated acetaminophen, and the toxicity caused by the chemicals showed a dose-dependent manner. The synergistic effect of caffeine and acetaminophen was observed when both caffeine and acetaminophen were supplemented to culture medium. At the concentration 1mM, caffeine enhanced the intracellular GSH depletion and MDA formation by 63% and 64%, respectively, compared to single supplementation of 10mM acetaminophen in culture medium. This hepatotoxicity induced membrane integrity loss was observed by lightmicroscope on the simultaneous administration of caffeine and acetaminophen in monolayer cultured hepatocytes. Co-supplementation of vitamins with caffeine/acetaminophen to culture medium results in the protection of hepatocytes from hepatotoxic attach by caffeine/acetaminophen. Especially, vitamin E was superior to vitamin C and $\beta$-carotene from the standpoints of GSH depletion and MDA formation. From this results, it has been speculated that vitamin E may play a role of antioxidant scavenging radicals produced from acetaminophen. Taken all together, in vitro culture system like monolayer culture of hepatocytes may be a useful tool for the evaluation of hepatotoxicity or protection ability of food ingredients.

• Toxicological Research
• /
• 제3권1호
• /
• pp.1-8
• /
• 1987

In vitro induction of cytochrome 450 associated monooxygenase activities by phenobarbital (PB) and 3-methylcholanthrene (MC) was investigated in primary cultures of adult rat hepatocytes. PB and MC were added to the culture 24 hr after the initial plating of hepatocytes. A signiftcant increase of the activities of 7-ethoxycoumarin 0-deethylase and aryl hydrocarbon hydroxylase were observed in MC and PB treated culture. MC caused about 500% induction of the initial oxidation rates of both enzymes in 48 hr. However the PB maintained both enzyme activities close to the level of freshly isolated hepatocytes. Biphenyl 4-hydroxylase and aminopyrine N-demethylase activities were also induced by MC and PB. But the level of induction was less than that occuring with 7-ethoxycoumarin 0-deethylase and aryl hydrocarbon hydroxylase. When aflatoxin $B_1$ was added to the hepatocyte cultures which have been treated with MC or PB, it caused a significant increase of the unscheduled DNA synthesis at higher dose of aflatoxin $B_1$ as compared to those of untreated control hepatocyte cultures. The results suggest that microsomal enzyme activities can be selectively controlled preferably in hepatocyte cultures by the in vitro induction method. This principle may be useful for studying the metabolism and other toxicological studies.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2003년도 생물공학의 동향(XIII)
• /
• pp.305-306
• /
• 2003

To treat fulminant hepatic failure (FHF) patients, various extracorporeal bioartificial liver (BAL) systems have been developed. Several requirements should be met for the development of BAL systems: hepatocytes should be cultured in a sufficiently high density; their metabolic functions should be of a sufficiently high level and duration; and the BAL systems module should permit scaling-up and aseptic handling. Several investigators have found that freshly isolated primary hepatocytes can be cultured into three dimensional, tightly packed, freely suspended, multicellular aggregates, or spheroids. These specialized cell structures exhibited enhanced liver specific functions and a prolonged differentiated state compared to cells maintained in a monolayer culture. Cells in spheroids appear to mimic the morphology and ultrastructure of the in vivo liver lobule. The ability of hepatocytes to organize into three-dimensional structures was hypothesized to contribute to their enhanced liver-specific activities. In this study, the ammonia removal rate and urea secretion rate of pig hepatocytes spheroids encapsulated in Ca-alginate bead were determined. A packed-bed bioreactor with encapsulated pig hepatocytes was devised as BAL support system. The efficacy of the system was evaluated in vitro.

• Macromolecular Research
• /
• 제11권6호
• /
• pp.488-494
• /
• 2003

We have fabricated gelatin-immobilized polyurethane foams (PUFG) by dipping polyurethane foam (PUF) in an aqueous solution containing gelatin and by subsequent reaction with glutaraldehyde after freeze-drying. Gelatin aqueous solutions of different concentrations were used as the dipping solutions to control the amount of immobilized gelatin. The average pore size of PUF decreased with an increase in gelatin concentration. It was found from the hepatocyte adhesion experiment that the amount of hepatocytes seeded on PUFG1, prepared by using a 1% aqueous gelatin solution, was higher than that on other PUFGs. The hepatocytes inoculated in PUFG1, were slightly aggregated as the incubation time increased. The cells inoculated in PUFG1 showed higher ammonia removal ability than those monolayer-cultured on a gelatin-immobilized polystyrene dish (PSG) after 1 and 4 days of incubation time. The inoculated cells exhibited higher albumin secretion relative to monolayer-cultured hepatocytes on PSG. Albumin secretion by hepatocytes seeded on PUFG1 was increased by the presence of serum and was further increased by both the presence of serum and cytokines. The results obtained from a 3-(3,4-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) assay indicated that PUFG can provide a better microenvironment for hepatocyte culture along with nutrition and metabolite transfer through the high porosity of PUF.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제8권1호
• /
• pp.41-46
• /
• 2003

Difficulties associated with bioartificial liver (BAL) preservation limit not only the commercialization of BAL, but also its clinical trials. In this study, the possibility of cold preservation of BAL cartridges containing porcine hepatocytes was examined at 4$^{\circ}C$. In an in vitro perfusion culture System, BAL cartridges maintained cytochrome P450 metabolic function for at least 50 days. However, all BAL cartridges completely lost their ammonia eliminating ability when stored at 4$^{\circ}C$. We a1so studied the effect of cell density on the maintenance of BAL liver function In a highly differentiated and healthy state. As expected, BALs containing a larger number of hepatocytes demonstrated higher metabolic functions. When metabolic functions were compared per gram of hepatotytes, no large differences were observed between devices containing different densities of hepatocytes. Decreased cell density did not Successfully prolong BAL function. The viability and function of isolated hepatotytes highly depend on the culture conditions, such as cell density, substrata, culture media, and additives to the culture media. Perfusion culture of BAL cartridges at 4$^{\circ}C$ gave a promosing result with respect to the maintenance of P450 activity. However, as indicated by the rapid loss of ammonia metabolic activity, many factors still remain to be optimized for preservation of BAL keeping high metabolic functions for a longer time.

• 한국식품영양과학회지
• /
• 제20권1호
• /
• pp.46-51
• /
• 1991

• 한국식품영양과학회지
• /
• 제20권1호
• /
• pp.45-45
• /
• 1991

• Fisheries and Aquatic Sciences
• /
• 제4권4호
• /
• pp.180-185
• /
• 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.

• Fisheries and Aquatic Sciences
• /
• 제1권1호
• /
• pp.19-23
• /
• 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.

• Archives of Pharmacal Research
• /
• 제21권6호
• /
• pp.718-722
• /
• 1998

Scopoletin (7-hydroxy-6-methoxycoumarin), a coumarin, was isolated from the aerial part of Solanum lyratum Thunb. by the activity-guided fractionation employing carbon te trachloride-intoxicated primary cultured rat hepatocytes as a screening system. Its hepatoprotective activity was first evaluated by measuring the release of glutamic pyruvic transaminase and sorbitol dehydrogenase from carbon tetrachloride-intoxicated rat hepatocytes into the culture medium. Scopoletin significantly reduced the releases of glutamic pyruvic transaminase and sorbitol dehydrogenase from the carbon tetrachloride-intoxicated primary cultured rat hepatocytes by 53% and 58%, respectively, from the toxicity in a dose-dependent manner over concentration ranges of 1mcM to 50mcM. Further studies revealed that at the concentration of 10mcM, scopoletin significantly preserved glutathione content by 50% and the activity of superoxide dismutase by 36% and also inhibited the production of malondialdehyde to the degree as seen in the control.