• Biomedical Science Letters
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• v.11 no.1
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• pp.45-49
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• 2005

The change of catechol-O-methyltransferase (COMT) activity during regeneration of rat liver was studied. Cytosolic, mitochondrial and microsomal COMTs activities were estimated in regenerating rat livers over a period of ten days after $70\%$ (median and left lateral lobes) partial hepatectomy. The values of Km and Vmax in the hepatic enzymes were also measured. The activities of cytosolic and microsomal COMTs in regenerating rat liver after partial hepatectomy were found to be significantly increased between the second and the third day. Whereas the mitochondrial COMT activity did not change. The Vmax values of the cytosolic and microsomal COMTs in the regenerating rat liver were significantly increased at the second day after partial hepatectomy, however, the Km values of the above hepatic enzymes did not vary in all the experimental groups. Therefore, the results suggest that the biosynthesis of COMT was increased during the regeneration of rat liver.

• Applied Microscopy
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• v.18 no.2
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• pp.205-217
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• 1988

An ultrastructural study of hepatocyte proliferation in the regenerating rat liver has been made by means of the partial hepatectomy. And electron microscopic histochemistry of hepatocyte in the regenerating rat liver is studied through alkaline phosphatase reaction. The results are as follows: 1. When the regeneration of rat liver is induced by the partial hepatectomy, the prominent ultrastructural characteristics of hepatocyte are changes of the distribution of chromatin in nucleus, increase of the number of mitochondria and decrease of the size of them, development of rough endoplasmic reticulum, and transient decrease of glycogen granules in cytoplasm. 2. Alkaline phosphatase reaction products are appeared in the nucleus or rough endoplasmic reticulum of hepatocyte during the initial regeneration of liver as 24, 48 and 72 hour groups after partial hepatectomy. And these positive reaction are mainly increased in cytoplasm and plasma membrane of hepatocytes during 1, 2 and 3 week groups after partial hepatectomy. As 4 weeks passed after partial hepatectomy, these positive reaction is located in the sinusoidal epithelial cells or erythrocytes. With above results, we concluded that alkaline phosphatase was synthesized in the rough endoplasmic reticulum bounded ribosomes of regenerating hepatocyte, was transported to the plasma membrane of them, and then was transported in blood by the way sinusoidel epithelial cells.

• YAKHAK HOEJI
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• v.32 no.4
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• pp.239-244
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• 1988

Transcriptional rate of lactate dehydrogenase A-gene(LDH-A) during the prereplicative phase of regenerating rat liver was determined by in vitro run-off transcription assay. The results show that the transcription rate of LDH A-gene increases between 12 hours and 15 hours peaking at 13 hours after partial hepatectomy of rat liver. The increased rate of LDH A-gene transcription was interfered after DL-propranolol treatment intraperitoneally injected twice at 1 hour and 8 hours after partial hepatectomy indicating that the transcriptional control of LDH A-gene expression may be mediated by beta adrenergic receptor and cAMP as a second messenger. And also was it shown that the temporally increased rate of LDH A-gene transcription was maximum one hour after the second cAMP-surge which is known to play an important role for the initiation of DNA replication during regeneration of rat liver. And the transcriptional rate of LDH A-gene was decreased to the basal level at the time period when the hepatocytes proliferate rapidly suggesting that the induced LDH Aisozyme may be required for the initiation of DNA replication during regeneration of rat liver. These data may be supporting for the hypothesis suggesting that the induced LDH A-isozyme during the pre-replicative phase of regenerating rat liver may play bifunctional roles as a glycolytic enzyme and a helix destablizing protein as well.

• Proceedings of the Ginseng society Conference
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• 1990.06a
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• pp.58-64
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• 1990

The effects of ginseng saponins, G-Rbl and G-Rc on the rat liver LDH A-gene transcnptional activity was investigated during pro-replicative phase of rat liver after partial hepatectomy. Changes in LDH A-mRNA levels in regenerating rat liver after intraperitoneal administrations of G-Rbl of G-Rc were tested by slot blot hybridization methods. The results showed that G-Rbl (1 mg/100g B.W) and G-Rc (1 ma/100g B.W) caused marked increases of LDH A-mRNA contents by respectively 1.9- and 1.5-fold in rat liver at 5·hours after partial hepatectomy. Dose dependent effect of G-Rbl and G-Rc (1-25 mg/100g B.W) on the LDH A-mRNA levels on regenerating rat liver were also analyzed. The maximal in- creases of liver LDH A-mRNA levels were observed with the doses of 1 mg for G-Rbl and 5 mg for G-Rc However, when the administration doses of G-Kbl and G-Rc were increased to 20 mg, G-Rbl caused a marked decrease of LDH A-mRNA level to 61% of those in sham-operated rat liver In contrast, G-Rc slightly decreased the liver LDH A-mRNA contents by 30% as compared to those of the maximum value but still maintained 22% higher LDH A-mRNA levels then those of sham-operated rate liver. On the basis of these experimental results, we conclude that ginseng saponin, G-Rb 1 and G·Rc have stimulatory effect at the lower concentration (1 mg/100g B.W) and inhibitory effect at the higher concentration (20 moi loos 5.W) on the LDH A-gene transcription during regeneration of rat liver, Additionally we also investigated the stimulatory effects of ginsenosides on the protein and DNA synthetic activities in hepatocyte primary cell cultures isolated from regenerating rat liver. Both of G·Rc and -Re increased the synthetic rates of hepatocytes proteins and DNA at the administration doses of 50 ug and 100 ug/3 ml/dish respectively representing 1.3-1.6 fold increases. From these results we postulate that G-Rc and -Re may have a mitogen enhancer activity for the hepatocyte proliferation during rat liver regeneration period. Keywords Inductive effects of ginsenosides, G-Rb, -Rc, and -Re, rat LDH A-gene transcription, the sin thetic rate of proteins and DNA in regeneration rat liver.

• Journal of Ginseng Research
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• v.14 no.2
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• pp.200-206
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• 1990

The effects of ginseng saponins, SRbl and G-Rc on the rat liver LDH A-gene transcriptional activity was investigated during prereplicative phase of rat liver after partial hepatectomy. Changes in LDH A-mRNA levels in regenerating rat liver after intraperitoneal administrations of G-Rbl or 'G-Rc were tested by slot blot hybridization methods. The results showed that G-Rbl (1 mg/100g B.W) and G-Rc (1 mg/100g B.W) caused marked increases of LDH A-mRNA contents by respectively 1.9- and 1.5-fold in rat liver at 5-hours after partial hepatectomy Dose dependent elect of G-Rbl and G-Rc (1-25 mg/ 100g B.W) on the LDH A-mRNA levels on regenerating rat liver were also analyzed. The maximal increases of liver LDH A-mRNA levels were observed with the doses of 1 mg for G-Rbl and 5 mg for G-Rc. However, when the administration doses of G-Rbl and G-Rc were increased to 20 mg, G-Rbl caused a marked decrease of LDH A-mRNA level to 61% of those in sham-operated rat liver. In contrast, G-Rc slightly decreased the liver LDH A-mRNA contents by 30% as compared to those of the maximum value but still maintained 22% higher LDH A-mRNA levels then those of sham-operated rate liver. On the basis of these experimental results, we conclude that ginseng saponin, G-Rbl and G-Rc have stimulatory effect at the lower concentration (1 mg/ 100g B.W) and inhibitory effect at the higher concentration (20 mg/ 100g B.W) on the LDH A-gene transcription during regeneration of rat liver. Additionally we also investigated the stimulatory effects of ginsenosides on the protein and DNA sinthetic activities in hepatocyte primary cell cultures isolated from regenerating rat liver. Both of G-Rc and -Re increased the synthetic rates of hepatocytes proteins and DNA at the administration doses of 50 us and 100 $\mu\textrm{g}$/3 ml/dish respectively representing 1.3-1.6 fold increases. From these results we postulate that G-Rc and -Re may have a mitogen ehincer activity for the hepatocyte proliferation during rat liver regeneration period.

• BMB Reports
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• v.32 no.1
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• pp.45-50
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• 1999

We previously found three transcription factor-binding motifs in the rat p53 promoter. They are two recognition motifs of NF1-like protein (NF1-like element 1: -296 ~ -312, NF1-like element 2: -195 ~ -219) and a bHLH protein binding element (-142 ~ -146). In this study, we investigated the DNA-protein complex formation of the three elements with nuclear extracts from both normal and regenerating liver to find the element involved in the induced transcription of p53. The level of each DNA-protein complex on NF1-like and bHLH motifs was not changed. Instead, a new element located at -264 ~ -284 was detected in the DNase I footprinting assay with regenerating nuclear extract. This element has partial homology to the AP1 consensus motif. However, the competition studies with diverse oligonucleotides suggest that the binding protein is not AP1. An in vitro transcription assay shows that this element is important for the transcriptional activation of the rat p53 promoter. Therefore, for the induced transcription of the rat p53 promoter, the-264 ~ -284 region is required in addition to two NF1-like and one bHLH motif.

• Archives of Pharmacal Research
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• v.20 no.3
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• pp.239-246
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• 1997

In the present study, liver regeneration rate (%) was increased up to 70% 3 days after partial hepatectomy (PH). Nitric oxide synthase (NOS) activity in liver tissue as well as serum nitrite/ nitrate content had no timed response, revealing no significant difference between shamoperated and partially hepatectomized rat liver. Contents of free methylarginines in liver tissue were increased biphasically in a time-dependent manner after PH. However, those in serum did not exhibit the same patterns as in liver. Taken together, the results suggest that $N^{G}$-monomethyl-L-arginine (MMA) and $ N^{G}, N^{G}$-dimethylarginine (DMA) play a role in inhibiting nitric oxide (NO) synthesis in regenerating rat liver because the increase of their contents was synchronized with NOS expression.

• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.232.1-232
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• 1998

No Abstract, See Full Text

• Animal cells and systems
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• v.5 no.3
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• pp.263-266
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• 2001

Metallothionein (MT) is induced in the regenerating rat liver. We have investigated expression of MT gene by RT PCR as well as specific localization of MT by immunocytochemistry in regenerating rat liver after partial hepatectomy (PH). MT mRNA level started to increase from 1 h and reached the peak at 8 h after PH. The level decreased gradually by 24 h, and became similar to that of control group. In the immunocytochemical study, in all groups treated with primary antibody, immunogold particles indicating the presence of MT were evenly distributed throughout both cytoplasm and nucleus of the rat hepatocytes. Within the nucleus, the gold particles appeared to be intensely localized in the areas of euchromatin and nucleolus. Within the cytoplasm, gold particles did not seem to adhere to mitochondria or Iysosomes, but were freely distributed. However, rough endoplasmic reticulum was the obvious compartment on which the gold particles were localized. Time course of MT immunoreactivity revealed that distribution of gold particles in hepatocytes increased gradually by 24 h, and decreased at 48 h after PH. Briefly, PH resulted in the sharpest increase in the expression of MT mRNA at 8 h and in the immunoreactivity of MT at 24 h, respectively. It is suggested that the increase of MT mRNA expression, the intensity of immunoreactivity and the specific localization of MT may be associated with the compensatory cell proliferation followed by PH.

• Smart Media Journal
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• v.9 no.3
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• pp.59-70
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• 2020

This paper presents a fully automatic tool to recognize the liver region from CT images based on a deep learning model, namely Multiple Filter U-net, MFUnet. The advantages of both U-net and Multiple Filters were utilized to construct an autoencoder model, called MFUnet for segmenting the liver region from computed tomograph. The MFUnet architecture includes the autoencoding model which is used for regenerating the liver region, the backbone model for extracting features which is trained on ImageNet, and the predicting model used for liver segmentation. The LiTS dataset and Chaos dataset were used for the evaluation of our research. This result shows that the integration of Multiple Filter to U-net improves the performance of liver segmentation and it opens up many research directions in medical imaging processing field.