• 한국임상약학회지
• /
• 제7권1호
• /
• pp.33-39
• /
• 1997

Cardiac and antihypertensive effects of BMS-180448, a cardiac-selective ATP-sensitive potassium channel opener, and its newly synthesized derivatives KR-31281, KR-31282 and KR-31299 were evaluated in isolated perfused rat hearts (25 min global ischemia/30 min reperfusion) and conscious rats. Three new compounds $(10\;{\mu}M)$ induced positive inotropism as evidenced by increased LVDP (left ventricular developed pressure) and RPP (Rate-Pressure Product) in nonischemic rat heart. HR-31299 increased CF (coronary flow) and HR (heart rate) but the other two had no effects. KR-31282, KR-31281 and HR-31299 had a tendency to increase reperfusion LVDP and RPP compared with vehicle, while the latter two significantly reduced reperfusion EDP with a tendency to inclose TTC (time to contracture). All three KR-compounds had very weak effects on MBP and HR in conscious rats. These results indicate that KR-31281 and HR-31299 may have some cardioprotective effects, although weaker than BMS-180448, and their mode of action different from that of BMS-180448, despite the similarity in major structural moeity.

• The Korean Journal of Physiology and Pharmacology
• /
• 제6권4호
• /
• pp.183-186
• /
• 2002

Ischemic damage is one of the most serious problems. The openers of KATP channel have been suggested to have an effect to limit the ischemic damage. However, it is not yet clear how KATP channels of a cell correspond to hypoxic damage. To address the question, N2a cells were exposed to two different hypoxic conditions as follows: 6 hours hypoxia followed by 3 hours reperfusion and 12 hours hypoxia followed by 3 hours reperfusion. As the results, 6 hours hypoxic treatment increased glibenclamide- sensitive basal $K_{ATP}$ current activity (approximately 6.5-fold at 0 mV test potential) when compared with nomoxic condition. In contrast, 12 hours hypoxic treatment induced a relatively smaller change in the $K_{ATP}$ current density (2.5-fold at 0 mV test potential). Additionally, in experiments where $K_{ATP}$ channels were opened using diazoxide, the hypoxia for 6 hours significantly increased the current density in comparison to control condition (p＜0.001). Interestingly, the augmentation in the $K_{ATP}$ current density reduced after exposure to the 12 hours hypoxic condition (p＜0.001). Taken together, these results suggest that $K_{ATP}$ channels appear to be recruited more in cells exposed to the 6 hours hypoxic condition and they may play a protective role against hypoxia-reperfusion damage within the time range.

• Journal of Ginseng Research
• /
• 제33권4호
• /
• pp.268-277
• /
• 2009

Ginsenosides are among the most well-known traditional herbal medicines frequently used for the treatment of cardiovascular symptoms in South Korea. The anti-ischemic effects of compound K (CK), a metabolite of ginsenoside Rb1, on ischemia-induced isolated rat hearts were investigated through the analyses of the changes in the hemodynamics (blood pressure, aortic flow, coronary flow, and cardiac output) and the measurement of the infarct region. The subjects in this study were divided into four groups: the normal control, the CK-alone group, the ischemia-induced group without any treatment, and the ischemia-induced group treated with CK. No significant differences in perfusion pressure, aortic flow, coronary flow, and cardiac output were found between the groups before ischemia was induced. The oxygen and buffer supply was stopped for 30 min to induce ischemia 60 min after reperfusion in the isolated rat hearts, and the CK was administered 5 min before ischemia induction. The CK treatment significantly prevented decreases in perfusion pressure, aortic flow, coronary flow, and cardiac output under ischemic conditions. In addition, the hemodynamics (except for the heart rate) of the group treated with CK significantly recovered 60 min after reperfusion, unlike in the control group. CK significantly limited the infarct. These results suggest that CK treatment has distinct anti-ischemic effects in an exvivo model of an ischemia-reperfusion-induced rat heart.

• Journal of Ginseng Research
• /
• 제33권4호
• /
• pp.283-293
• /
• 2009

Ginsenosides, one of the most well-known traditional herbal medicines, are used frequently in Korea for the treatment of cardiovascular symptoms. The effects of ginseng saponin on ischemia-induced isolated rat heart were investigated through analyses of hemodynamic changes including perfusion pressure, aortic flow, coronary flow, and cardiac output. Isolated rat hearts were perfused and then subjected to 30 min of global ischemia followed by 60 min of reperfusion with modified Kreb's Henseleit solution. Myocardial contractile function was continuously recorded. Ginseng saponin administered before inducing ischemia significantly prevented decreases in perfusion pressure, aortic flow, coronary flow, and cardiac output. The ginseng saponin administered group significantly recovered all of the hemodynamic parameters, except heart rate, after ischemia-reperfusion (I/R) compared with ischemia control. The intracellular calcium ($[Ca^{2+}]_i$) content in rat neonatal cardiomyocytes was quantitatively determined. Administration of ginseng saponin significantly prevented $[Ca^{2+}]_i$ increase that had been induced by simulated I/R in vitro (p<0.01) in a dose-dependent manner, suggesting that the cardioprotection of ginseng saponin is mediated by the inhibition of $[Ca^{2+}]_i$ increase. Overall, we found that the administration of ginseng saponin has cardioprotective effects on the isolated rat heart after I/R injury. These results indicate that ginseng saponin has distinct cardioprotective effects in an I/R-induced rat heart.

• Archives of Pharmacal Research
• /
• 제28권12호
• /
• pp.1386-1391
• /
• 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.

• 한국자원식물학회지
• /
• 제31권3호
• /
• pp.268-273
• /
• 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.

• Journal of Chest Surgery
• /
• 제44권4호
• /
• pp.273-278
• /
• 2011

Despite aggressive treatment, the mortality rate of cardiogenic shock with acute myocardial infarction (AMI) is high. We performed extracorporeal membrane oxygenation (ECMO) prior to coronary reperfusion, and evaluated the early clinical results and risk factors. Materials and Methods: From May 2006 to November 2009, we reviewed the medical records of 20 patients in cardiogenic shock with AMI (mean age $67.7{\pm}11.7$ yrs, M : F 14 : 6). After initially performing ECMO using the CAPIOX emergency bypass system ($EBS^{(R)}$Terumo, Tokyo, Japan), patients underwent coronary reperfusion (coronary artery bypass grafting, 13; percutaneous coronary intervention, 7). Results: All patients were in a cardiogenic shock state, cardiopulmonary resuscitations (CPR) were performed for fourteen patients (mean CPR time $20.8{\pm}26.0$ min). The mean time from vascular access to the initiation of ECMO was $17.2{\pm}9.4$ min and mean support time was $3.8{\pm}4.0$ days. Fourteen patients were able to be weaned from ECMO and ten patients were discharged (mean admission duration $50.1{\pm}31.6$ days). Patients survived on average $476.6{\pm}374.6$ days of follow-up. Longer CPR and support time, increased cardiac enzyme, lower ejection fraction, lower albumin, and major complications were the risk factors of mortality (p<0.05). Conclusion: The early application of ECMO prior to coronary reperfusion and control of risk factors allowed for good clinical results in cardiogenic shock with AMI.

• Biomolecules & Therapeutics
• /
• 제13권1호
• /
• pp.20-25
• /
• 2005

The present study was performed to evaluate antiarrhythmic effects of KR-32570, a novel inhibitor of sodium hydrogen exchanger subtype-1 (NHE-1), in rat arrhythmia induced by focal ischemia and reperfusion. During ischemia, KR-32570 significantly decreased the number of premature ventricular contraction (PVC) from 152.0 times to 75.5, 52.4 and 20.0 times for 0.1, 0.3 and 1.0 mg/kg, respectively (p<0.05) and the duration of ventricular tachycardia (VT) from 88.1 s to 35.8, 7.7 and 1.3 s, respectively(p<0.05) in anesthetized rats subjected to 10-min coronary occlusion of coronary artery. Similarlt to ischemia-induced arrhythmia, KR-32570 significantly decreased reperfusion-induced arrhythmia including PVC (41.3, 21.5, 11.3 and 6.6 times at vehicle, 0.1, 0.3 and 1.0 mg/kg, respectively, p<0.05) and VT (100.5, 64.2, 25.8 and 25.2 s, respectively, p<0.05), and VF (86.9, 27.5, 6.9 and 0 s, respectively, p<0.05). Moreover, KR-32570 dose-dependently decreased the incidence of mortality occurring after reperfusion (41, 27, 18 and 0% at vehicle, 0.1, 0.3, 1.0 mg/kg, respectively). These results suggest that KR-32570 has a potent antiarrhythmic effect in rat arrhythmia induced by ischemia and reperfusion.

• The Korean Journal of Physiology and Pharmacology
• /
• 제18권1호
• /
• pp.67-72
• /
• 2014

To investigate the alteration of c-Jun N-terminal kinase (JNK) activity after myocardial ischemia reperfusion injury (MIRI) and further explore the effect of naloxone postconditioning on MIRI. Forty male Sprague Dawley rats were randomly divided into five groups: sham operation (sham, n=8); ischemia reperfusion (IR, n=8); IR+naloxone 0.5 mg/kg (Nal L, n=8); IR+naloxone 1.0 mg/kg (Nal M, n=8); IR+naloxone 2.0 mg/kg (Nal H, n=8). Pathological changes of myocardial tissue were visualized by HE staining. The expression of p-JNK, and the apoptosis of cardiomyocytes were investigated with Western blotting and the TUNEL assay, respectively. Irregular arrangement and aberrant structure of myocardial fibers, cardiomyocytes with granular or vacuolar degeneration, and inflammatory cells infiltrating the myocardial interstitial regions characterized MIRI in the IR group. Signs of myocardial injury and inflammatory infiltration were less prominent in the Nal-treated groups. The expression of p-JNK in the sham group and in all Nal-treated groups was significantly lower than that in the IR group (p<0.01). The apoptosis index of cardiomyocytes in the IR group was significantly higher than in the sham group (p<0.01). The apoptosis indices of cardiomyocytes in all Nal-treated groups were significantly reduced to 55.4%, 26.2%, and 27.6%, respectively, of the IR group (p<0.01). This study revealed that Naloxone postconditioning before reperfusion inhibits p-JNK expression and decreases cell apoptosis, thus alleviating MIRI.

• Nutrition Research and Practice
• /
• 제4권3호
• /
• pp.196-202
• /
• 2010

To investigate the neuroprotective effects of bovine colostrums (BC), we evaluate the ability of consuming BC after focal brain ischemia/reperfusion injury rat model to reduce serum cytokine levels and infarct volume, and improve neurological outcome. Sprague-Dawley rats were randomly divided into 4 groups; one sham operation and three experimental groups. In the experimental groups, MCA occlusion (2 h) and subsequent reperfusion (O/R) were induced with regional cerebral blood flow monitoring. One hour after MCAO/R and once daily during the experiment, the experimental group received BC while the other groups received 0.9% saline or low fat milk (LFM) orally. Seven days later, serum pro-inflammatory cytokine (IL-$1{\beta}$, IL-6, and TNF-${\alpha}$) and anti-inflammatory cytokine (IL-10) levels were assessed. Also, the infarct volume was assessed by using a computerized image analysis system. Behavioral function was also assessed using a modified neurologic severity score and corner turn test during the experiment. Rats receiving BC after focal brain I/R showed a significant reduction (-26%/-22%) in infarct volume compared to LFM/saline rats, respectively (P < 0.05). Serum IL-$1{\beta}$, IL-6, and TNF-${\alpha}$ levels were decreased significantly in rats receiving BC compared to LFM/saline rats (P < 0.05). In behavioral tests, daily BC intake showed consistent and significant improvement of neurological deficits for 7 days after MCAO/R. BC ingestion after focal brain ischemia/reperfusion injury may prevent brain injury by reducing serum pro-inflammatory cytokine levels and brain infarct volume in a rat model.