• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.04a
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• pp.97-97
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• 1997

It was reported that ATP depletion occurs and accelerates cell damage during ischemia and reperfusion. To determine the mechanism of cell damage, the change of energy metabolism in liver was studied during ischemia/reperfusion. The groups were divided into four categories : sham-operated group, ischemia/reperfusion group, and two types of ATP-MgCl$_2$ treatment groups(one was treated during ischemia and the another during reperfusion). Rats were administered intravenously saline or ATP-MgCl$_2$. Rats were anesthetized and blood vessels in the left and median lobes of the liver were occluded. After 60min of ischemia, the clamp at those vessels were removed. After ischemia, one and five hours after reflow, energy metabolites(ATP, ADP, AMP, inosine, adenosine, hypoxanthine, xanthine) in liver were measured with HPLC. To observe mitochondrial function, aterial keton body ratio in blood and mitochondrial glutamate dehydrogenase activity in liver were measured. And lipid peroxidation was measured to evalutate the involvement of free radicals. In this study, ATP and ADP were catabolized to their metabolites(AMP, inosine, adenosine, hypoxanthine, xanthine) during ischemia and they resynthesized ATP and ADP during reperfusion. But total purine base were not restored to level of normal rat. The main source of resynthesizing ATP and ADP was AMP. In both ATP-MgCl$_2$ treated groups, mitochondrial function was protected and lipid peroxidation was significantly reduced. Our findings suggest that ischemia/reperfusion impairs hepatic energy metabolism.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.340-340
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• 1994

Since total hepatic ischemia(IS) occurs with transplantation, there has been interest in evaluating hepatic function after ischemia and subsequent reflow of blood. Four groups of animals were studied: group 1 (sham), group 2 (30mins IS), group 3 (60mins IS), and g.cup 4 (90mins IS). Serum transaminase(STA), wet weight-to-dry weight ratio(W/D), lipid peroxides(LPO), glucose-6-phosphatase(G-6-Pase) activity, Na$\^$+//K$\^$+/-ATPase(ATPase) activity were measured at 1, 5 and 24hrs after hepatic ischemia. Significant changes occurred between 1 and 5hrs of reperfusion. STA was 3579${\pm}$401, 4593${\pm}$675 and 6348${\pm}$808 U/L in group 2, 3 and 4 respectively. These changes were ischemic time-dependent manner. W/D in group 3 and 4 were significantly increased than that in sham group at all time points measured. In sham group, the level of LPO in the liver microsome remained constant at approximately 0. 5nmole MDA formed/mg protein througllout the experiment, In all ischemic groups on the other hand, the level of LPO started to increase at ischemia and markedly increased at all reperfusion period. Similar to STA, these changes were also dependent on duration of ischemia. Although G-6-Pase activity remained unchanged in both group 2 and group 3 until 5hrs of reperfusion, marked decrease in G-6-Pase activity was observed at grcup 4. ATPase activity was significantly decreased at 1, 5 and 24 hrs of reperfusion in group 3, whereas it was not changed in group 2. Furthermore, ATPase activity in group 4 started to decrease at ischemia and markedly decreased for entire reperfusion period. These data suggest that severity of hepatocellular injury is associated with period of ischemia as well as period of reperfusion.

• Archives of Pharmacal Research
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• v.27 no.1
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• pp.111-117
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• 2004

Hepatic microcirculatory failure is a major component of reperfusion injury in the liver. Recent data provided some evidence that endothelium-derived vasoconstrictors and vasodilators may be functionally important to the control of the total hepatic blood flow under these conditions of circulatory failure. Since Kupffer cells provide signals that regulate the hepatic response in ischemia/reperfusion (I/R), the aim of this study was to investigate the role of Kupffer cells in the I/R-induced imbalance of vasoregulatory gene expression. Rats were subjected to 60 min hepatic ischemia, followed by 5 h of reperfusion. The Kupffer cells were inactivated by gadolinium chloride ($GdCl_3$, 7.5 mg/kg body weight, intravenously) 1 day prior to ischemia. Liver samples were obtained 5 hrs after reperfusion for RT-PCR analysis of the mRNA for genes of interest: endothelin-1 (ET-1), its receptors $ET_A and ET_B$, endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS) and heme oxygenase-1 (HO-1). ET-1 mRNA expression was increased by I/R. mRNA levels for $ET_A$ receptors showed no change, whereas $ET_B$ receptor transcripts increased in the I/R group. The increases in ET-1 and $ET_B$ mRNA were not prevented by the $GdCI_3$ pretreatment. The mRNA levels for iNOS and eNOS significantly increased within the I/R group with no significant difference between the I/R group and the $GdCl_3$-treated I/R group. HO-1 mRNA expression significantly increased in the I/R group and this increase was attenuated by $GdCI_3$. In conclusion, we have demonstrated that an imbalance in hepatic vasoregulatory gene expression occurs during I/R. Our findings suggest that the activation of Kupffer cells is not required for I/R-induced hepatic microvascular dysfunction.

• Korean Journal of Plant Resources
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• v.30 no.6
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• pp.647-653
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• 2017

Hepatic ischemia-reperfusion injury (HIRI) is linked with high mortality rate. Several agents have been developed so far to reduce the risk of HIRI. In this study, we investigated the effects of Acanthopanax senticosus extract (AS) on hepatic ischemia-reperfusion. To explore the protective effects of A. senticosus extract injection (ASI) on hepatic ischemia-reperfusion injury rats animal model were used. After the development of HIRI by using clamping method rats were then randomly divided into five groups. Different doses of AS were administered in HIRI rat model. The level of ALT, AST, and MDA content in serum were detected in sham and HIRI groups. The activity of SOD, MPO and $Ca^{2+}-ATPase$, content of MDA, and cAMP in hepatic tissue were also measured. Expression of Bcl-2 and Bax protein were detected by immunohistochemical staining method. Compared with sham group, ASI has the protective effect on the HIRI model in rats. Blood levels of ALT, AST, SOD, MPO, and MDA were significantly lower in ASI group compared with HIRI. Indeed SOD and $Ca^{2+}-ATPase$ activities, MDA content, and cAMP level were improved in ASI group. Furthermore, Bcl-2 and Bax protein were improved in ASI group compared with only HIRI group. These results suggest that AS may provide potential ameliorative therapy by inhibiting the damage signaling mechanism in hepatic ischemia/reperfusion injury model.

• Biomolecules & Therapeutics
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• v.21 no.2
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• pp.132-137
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• 2013

Geniposide is an active product extracted from the gardenia fruit, and is one of the most widely used herbal preparations for liver disorders. This study examined the cytoprotective properties of geniposide and its metabolite, genipin, against hepatic ischemia/reperfusion (I/R) injury. C57BL/6 mice were subjected to 60 min of ischemia followed by 6 h of reperfusion. Geniposide (100 mg/kg) and genipin (50 mg/kg) were administered orally 30 min before ischemia. In the I/R mice, the levels of serum alanine aminotransferase and hepatic lipid peroxidation were elevated, whereas hepatic glutathione/glutathione disulfide ratio was decreased. These changes were attenuated by geniposide and genipin administration. On the other hand, increased hepatic heme oxygenase-1 protein expression was potentiated by geniposide and genipin administration. The increased levels of tBid, cytochrome c protein expression and caspase-3 activity were attenuated by geniposide and genipin. Increased apoptotic cells in the I/R mice were also significantly reduced by geniposide and genipin treatment. Our results suggest that geniposide and genipin offer significant hepatoprotection against I/R injury by reducing oxidative stress and apoptosis.

• Archives of Pharmacal Research
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• v.28 no.12
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• pp.1386-1391
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• 2005

This study examined the role of Kupffer cells in altering the hepatic secretory and microsomal function during ischemia and reperfusion (ls/Rp). Rats were subjected to 60 min of hepatic ischemia, followed by 1 and 5 h of reperfusion. Gadolinium chloride ($GdCl_{3}$, 7.5 mg/kg body weight, intravenously) was used to inactivate the Kupffer cells 1 day prior to ischemia. Is/Rp markedly increased the serum aminotransferase level and the extent of lipid peroxidation. $GdCl_{3}$ significantly attenuated these increases. Is/Rp markedly decreased the bile. flow and cholate output, and $GdCl_{3}$ restored their secretion. The cytochrome P450 content was decreased by Is/Rp. However, these decreases were not prevented by $GdCl_{3}$. The aminopyrine N-demethylase activity was decreased by Is/Rp, while the aniline p-hydroxylase activity was increased. $GdCl_{3}$ prevented the increase in the aniline p-hydroxylase activity. Overall, Is/Rp diminishes the hepatic secretory and microsomal drug-metabolizing functions, and Kupffer cells are involved in this hepatobiliary dysfunction.

• Biomolecules & Therapeutics
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• v.13 no.3
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• pp.127-132
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• 2005

We investigated whether ischemic preconditioning (IPC) protects liver against cold ischemic injury using isolated perfused rat liver. Rat livers were preconditioned by 5 minutes of ischemia and 5 minutes of reperfusion and preserved for 30 hours at $4^{\circ}C$ in University of Wisconsin solution. Livers were then reperfused for 120 minutes. Oxygen uptake and bile flow in ischemic livers markedly decreased during reperfusion. These decreases were prevented by IPC. Portal pressure was elevated in cold ischemic and reperfused livers and this elevation was prevented by IPC. Lactate dehydrogenase and purine nucleoside phosphorylase activities markedly increased during reperfusion. These increases were prevented by IPC. The ratio of reduced glutathione to glutathione disulfide was lower in ischemic livers. This decrease was prevented by IPe. Our findings suggest that IPC protects the liver against the deleterious effect of cold ischemia/reperfusion, and this protection is associated with the reduced oxidative stress.

• Biomolecules & Therapeutics
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• v.2 no.2
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• pp.141-148
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• 1994

This study was done to determine whether specific alterations exist in hepatic microsomal function after varying periods of ischemia (IS) and reperfusion (RP) during microsomal lipid peroxidation occurs. Rats were pretreated with $\alpha$-tocopherol to inhibit lipid peroxidation or with vehicle (soybean oil). Control animals were time-matched sham-ischemic animals. Four groups of animals were studied: Group 1 (sham), group 2 (30 mins IS), group 3 (60 mins IS) and group 4 (90 mins IS). After 1, 5 or 24 hr of reperfusion, liver microsomes were isolated and cytochrome P-450s were studied. In all vehicle-treated ischemic rats, serum ALT levels peaked at 5 hr and were significantly reduced by $\alpha$-tocopherol pretreatment. Similarly, microsomal lipid peroxidation was elevated in all vehicle-treated ischemic animal groups, but this elevation was prevented by $\alpha$-tocopherol pretreatment. Cytochrome P-450 content was significantly decreased in both group 3 and group 4. In all vehicle-treated ischemic animal groups, aminopyrine N-demethylase activity was significantly decreased for the entire reperfusion period. $\alpha$-Tocopherol inhibited reductions of cytochrome P-450 content and aminopyrine N-demethylase activity at both 1 hr and 5hr of reperfusion but did not affect the reduced levels of cytochrome P-450 content and aminopyrine N-demethylase activity at 24 hr of reperfusion. Aniline p-hydroxylase activity was significantly decreased in group 4, whereas it was increased in group 3. These decreases and increases were prevented by $\alpha$-tocopherol pretreatment. Our finding suggests that abnormalities in microsomal drug metabolizing function occur during hepatic ischemia and reperfusion in vivo and this is attributed to microsomal lipid peroxidation.

• Archives of Pharmacal Research
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• v.25 no.6
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• pp.940-945
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• 2002

The present study was done to determine the effect of trolox C, a hydrophilic analogue of vitamin E, on hepatic injury, especially the alteration in cytochrome P-450 (CYP)-dependent drug metabolism during ischemia and reperfusion (I/R). Rats were subjected to 60 min of hepatic ischemia and 5 h of reperfusion. Rats were treated intravenously with trolox C (2.5 mg/kg) or vehicle (PBS, pH 7.4), 5 min before reperfusion. Serum alanine aminotransferase and lipid peroxidation levels were markedly increased after I/R. This increase was significantly suppressed by trolox C. Cytochrome P-450 content was decreased after I/R but was restored by trolox C. There were no significant differences in ethoxyresorufin O-dealkylase (CYP 1A1) and methoxyresorufin O-dealkylase (CYP 1A2) activities among any of the experimental groups. Pentoxyresorufin O-dealkylase (CYP 2B1) activity was decreased and aniline p-hydroxylase (CYP 2E1) activity was increased after I/R. Both these changes were prevented by trolox C. Our findings suggest that trolox C reduces hepatocellular damage as indicated by abnormalities in microsomal drug-metabolizing function during I/R, and that this protection is, in part, caused by decreased lipid peroxidation.

• Korean Journal of Plant Resources
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• v.31 no.3
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• pp.268-273
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• 2018

Hepatic ischemia-reperfusion injury (HIRI) is linked with high mortality rate. Several agents have been developed so far to reduce the risk of HIRI. In this study, we investigated the effects of combined treatment of Ginko biloba leaves extract and vitamin C (GLEVC) on hepatic ischemia-reperfusion injury. To explore the protective effects of GLEVC on HIRI rats model were tested. After the development of HIRI by using clamping method rats were then randomly divided into four groups. Different doses of GLEVC were administered in HIRI rat model. The level of ALT, AST, SOD and MDA content in serum were detected in HIRI groups. Moreover, the activity of SOD, content of MDA, and GSH in hepatic tissue were also examined. Bcl-2 and Bax protein expression were detected by immunohistochemical staining method. Compared with sham group, GLEVC has the protective effect on the HIRI-induced model. Level of ALT, AST, and MDA in blood were significantly lower in GLEVC group compared with HIRI-induced group. Moreover, SOD activity and GSH were increased in GLEVC group whereas MDA content was reduced by GLEVC treatment. Furthermore, HIRI-induced Bax protein was reduced upon GLEVC treatment, whereas Bcl-2 protein expression was enhanced. These results demonstrate that GLEVC treatment may provide potential ameliorative therapy by reducing damaged signaling mechanism in hepatic ischemia/reperfusion injury model.