• Journal of Trauma and Injury
• /
• v.19 no.1
• /
• pp.14-20
• /
• 2006

Purpose: Although hypothermia has been used in many clinical situations, such as post cardiopulmonary resuscitation, stroke, traumatic brain injury, septic shock, and hemorrhagic shock, the mechanism by which it works has not been clearly elucidated. We aimed to evaluate the effect of hypothermia on the plasma nitric oxide (NO) concentration, lung iNOS expression, and histologic changes in intestinal ischemia-reperfusion (IR). Method: Male Sprague-Dawley rats were randomly divided into the hypothermia group (HT, n=8, $27{\sim}30^{\circ}C$) and the normothermia group (NT, n=8, $36{\sim}37^{\circ}C$). They underwent 30 min of intestinal ischemia by clamping the superior mesenteric artery, which was followed by 1.5 h of reperfusion. They were then sacrificed. The acute lung injury (ALI) score, the plasma NO concentration, and lung iNOS gene expression were measured. Results: Compared with the HT group, the NT group showed severe infiltrations of inflammatrory cells, alveolar hemorrhages, and interstitial hypertrophies in lung tissues. There were significant differences in the ALI scores between the NT and the HT groups ($8.7{\pm}1.5/HPF$ in NT vs $5.8{\pm}1.2/HPF$ in HT, p=0.008). Although the plasma NO concentration was slightly lower in the HT group, there was no significant difference between the two groups ($0.80{\pm}0.24{\mu}mol/L$ in NT vs $0.75{\pm}0.30{\mu}mol/L$ in HT, p=0.917). Lung iNOS gene expression was stronger in the NT group than in the HT group. The band density of the expression of iNOS in lung tissues was significantly increased in the NT group compared to the HT group ($5.54{\pm}2.75$ in NT vs$0.08{\pm}0.52$ in HT, p=0.002). Conclusions: This study showed that hypothermia in intestinal IR reduces inflammatory responses, ALI scores, and iNOS gene expression in lung tissues. There was no significant effect of hypothermia on the plasma NO concentration.

• Journal of Veterinary Clinics
• /
• v.29 no.5
• /
• pp.372-376
• /
• 2012

Acute kidney injury (AKI) is a serious problem associated with high morbidity and mortality. Ischemia-reperfusion is an important cause of acute kidney injury. This study was performed to ascertain clinically useful biomarkers for the diagnosis of AKI. In three miniature pigs, AKI were induced by 60 minutes of bilateral renal ischemia by the clamping renal artery. Blood and urine samples were collected from the pigs prior to clamping (baseline) and 0, 1, 3 and 5 days post-clamping. Serum blood urea nitrogen (BUN), creatinine, sodium and uric acid were measured in serum and urine samples. Fractional excretion of sodium ($FE_{Na}$) and fractional excretion of uric acid ($FE_{UA}$) were calculated. Also, interleukin (IL)-6, IL-18, liver type fatty acid binding protein (L-FABP) and glutathione-S-transferase (GST) were detected by Western immunoblotting. Serum BUN and creatinine levels were increased significantly at day 1 post-clamping in all three miniature pigs. However, $FE_{Na}$ and $FE_{UA}$ showed marked individual differences. Western immunoblotting revealed significantly increased levels of IL-6, IL-18, L-FABP and GST in post-ischemic urine, compared to pre-clamping. While more research concerning the variance of $FE_{Na}$ and $FE_{UA}$ is needed, serum BUN, creatinine, IL-6, IL-18, L-FABP and GST may be sensitive urine biomarkers for diagnosis of AKI together with other biomarkers in the porcine ischemia-reperfusion model.

• Toxicological Research
• /
• v.4 no.1
• /
• pp.23-35
• /
• 1988

The role of calcium in the production of oxygen radical which causes reperfusion damage of ischemic heart has been examined. The reperfusion damage was indrced in isolated Langendorff perfused rat hearts by aortic clamping for 60 min followed by reperfusion with oxygenated Krebs-Henseleit solution with or without 1.25 mM $CaCl_2.$ On reperfusion of the ischemic hearts with the calcium containing solution, the release of cytosolic enzymes (LDH and CPK) increased abruptly. These increased release of enzymes were significantly inhibited by additions of oxygen radical scavengers (SOD, 5,000 U; catalase, 12,500 U) into the reperfusion solution. In the hearts isolated from rats pretreated with allopurinol(20 mg/kg orally, 24 hr and 2 hr prior to the experiments), the levels of enzymes being released during reperfusion were significantly lower than that of the control. However, in the hearts perfused with the calcium-free but oxygenated solution, the increase in the release of cytosolic enzymes during reperfusion was neither inhibited by oxygen radical scavengers nor by allopurinol pretreatment. For providing the evidence of oxygen radical generation during the reperfusion of ischemic hearts in situ, the SOD-inhibitable reduction of exogenously administered ferricytochrome C was measured. In the hearts perfused with the calcium containing solution, the SOD-inhibitable ferricytochrome C reduction increased within the first minute of reperfusion, and was almost completely inhibited by allopurinol pretreatment. When the heart was perfused with the calcium free solution, however, the reduction of ferricytochrome C was not only less than that in the calcium containing condition, but also was not so completely inhibited by allopurinol pretreatment. By ischemia, xanthine oxidase (XOD) in the ventricular tissue was changed qualitatively, but not quantitatively. In the heart made ischemic with the calcium containing condition, the oxygen radical producing O-form of XOD increased, while the D- and D/O-form decreased. However, in the ischemic heart reperfused with the calcium free condition, the D/O-form of XOD was elevated without significant increase in O-form of the enzyme. It is suggested from these results that the calclum may play a contributing role in the genesis of reperfusion damage by promoting the conversion of xanthine oxidase from the D/O-form to the oxygen radical producing O-form in the ischemic myocardium.

• Journal of Ginseng Research
• /
• v.33 no.4
• /
• 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 Korean Neurosurgical Society
• /
• v.29 no.9
• /
• pp.1171-1178
• /
• 2000

Objective : The purpose of the present study was to determine the appropriate time of clinical intervention by observing and analyzing the changes in the size of infarct, penumbra and cerebral edema and the extend of neurological deficit due to reperfusion damage according to time in a reversible cerebral ischemic model of reperfusing blood flow after inducing ischemia by maintaining middle cerebral artery occlusion for 2 hours(h) in rats. Methods : The rats were divided according to reperfusion time into control group(0 h reperfusion time) and experimental groups(0.5, 1, 2, 3, 4, 5, 6, 12, and 24 h of reperfusion time). Results : Changes in the size of infarction due to reperfusion damage were 0.93, 1.48 and 1.16% at 0.5, 1 and 2 h after reperfusion, respectively, and although a statistical significance was not present compared to 1.35% of the control group, damages increased drastically up to 6 h(6.64%), and the size increased were 6.65 and 6.78% at 12 and 24 h, respectively. Also there was no significant difference after 6 h up to 24 h in the size of infarction. In the areas where infarction occurred, reperfusion damage increased significantly with time in cortex than in subcortex. Accordingly, the size of penumbra area also showed a statistically significant decrease from 2 h up to 6 h after reperfusion, and 6 h after reperfusion, the area almost disappeared, becoming permanent infarction. Thus, reperfusion damage showed a significant increase from 2 h up to 6 h after reperfusion, and became steady thereafter. As for the mean ratio of the extend of cerebral edema, the control group and reperfusion 0.5 h group were 1.073 and 1.081, respectively ; up to 2 h thereafter, the ratio decreased to 1.01 but increased again with time ; and in reperfusion 12 h and reperfusion 24 h, the ratios were 1.070 and 1.075, respectively, showing similar size with that of control group. As for neurological deficit scores, the score of the control group was 2.67, that of reperfusion 2 h was 2, those of reperfusion 3 h and 6 h groups were 3.2 and 3.8, respectively, and those of reperfusion 12 h and 24 h groups were 4.2 and 4.6, respectively. Thus, as for the test results, the neurological deficit increased with time 2 h after reperfusion, and in reperfusion 12 and 24 h groups, almost all the symptoms appeared. Conclusion : As shown in these results, although the changes in the size of infarction due to reperfusion damage did not increase up to 2 h after reperfusion in the experimental groups compared to the control group, damage increased significantly thereafter up to 6 h, and the size remained about the same from 6 h to 24 h after reperfusion, becoming permanent infarction ; thus, the appropriate time of intervention according to the present study is at least 6 h before after maintaining reperfusion, including the time of cerebral artery occlusion.

• The Korean Journal of Physiology and Pharmacology
• /
• v.20 no.2
• /
• pp.147-152
• /
• 2016

Present study aimed to investigate the effect of curcumin-pretreatment on intestinal I/R injury and on intestinal mucosa barrier. Thirty Wistar rats were randomly divided into: sham, I/R, and curcumin groups (n=10). Animals in curcumin group were pretreated with curcumin by gastric gavage (200 mg/kg) for 2 days before I/R. Small intestine tissues were prepared for Haematoxylin & Eosin (H&E) staining. Serum diamine oxidase (DAO) and tumor necrosis factor (TNF)-${\alpha}$ levels were measured. Expression of intestinal TNF-${\alpha}$ and tight junction protein (ZO-1) proteins was detected by Western blot and/or immunohistochemistry. Serum DAO level and serum and intestinal TNF-${\alpha}$ leves were significantly increased after I/R, and the values were markedly reduced by curcumin pretreatment although still higher than that of sham group (p<0.05 or p<0.001). H&E staining showed the significant injury to intestinal mucosa following I/R, and curcumin pretreatment significantly improved the histological structure of intestinal mucosa. I/R insult also induced significantly down-regulated expression of ZO-1, and the effect was dramatically attenuated by curcumin-pretreatment. Curcumin may protect the intestine from I/R injury through restoration of the epithelial structure, promotion of the recovery of intestinal permeability, as well as enhancement of ZO-1 protein expression, and this effect may be partly attributed to the TNF-${\alpha}$ related pathway.

• Journal of Chest Surgery
• /
• v.29 no.8
• /
• pp.807-815
• /
• 1996

The protective effect of'ischemic preconditioning'on ischemid-reperfusion injury of heart has been reported in various animal species. but without known mechAnism in detail, In An attempt to investigate the cardioprotective mechanism of ischemic preconditioning, we examined the effects of nitric oxide(UO) synthesis in preconditioned heart of rat The isolated hearts perfused by Langendorfr's method were ex- posed to 30min global ischemia followed by 30min reperfusion with oxygenated Krebs-Henseleit(K-H) sol- ution. Ischemic preconditioning was performed with three episodes of Sm n ischemia and Smin repeyfusion before the induction of prolong ischemia(30min)-reperfusion(30min). Ischemic preconditioning prevented the depression of cardiac function(left ventricular pressure .K heart rate) observed in the ischemia- reperfusion hearts and reduced the release of lactate dehydrogenase during the reperfusion period. On electromicroscopic pictures, myocardial ultrastructures wore relatively well preserved in isthemic preconditioned hearts. N6_nitro-L-arginine methyl ester(L-NAME) an inhibitor of L-arginine citric oxide pathway, was infused at a rate O.Smllmin In a dose of 10mg kg-1 before the initial ischemic preconditioning. neither the protection of cardiac function nor the reduction of LDH releAse in ischemic preconditioning hearts was altered in the presence of added L-NAME On ultrastructural finding, the preservation of morphology in ischemic preconditioning heart was not change by the pretreatment of L-UAME. The failure of the WO synthesis inhibitor to reduce t e effect of ischemic preconditioning may be related to be species specific in that NO may allot be the trigger for ischemic preconditioning in rats.

• Applied Microscopy
• /
• v.25 no.3
• /
• pp.51-62
• /
• 1995

It has been well known that ischemia and reperfusion injury to skeletal muscle following an acute arterial occlusion causes significant morbidity and mortality. The skeletal muscle, which contains high energy phosphate compounds, has ischemic tolerance. During the ischemia, the ATP is catalyzed to hypoxanthine anaerobically and hypoxanthine dehydrogenase is converted to xanthine oxidase. During reperfusion, the hypoxanthine is catalyzed to xanthine by xanthine oxidase under $O_2$, presence and that results in production of cytotoxic oxygen free radicals. These cytotoxic free radicals, $O_2^-,\;H_{2}O_2,\;OH^-$, are toxic and make lesions in skeletal muscle during reperfusion. The authors perform the present study to investigate the effects of allopurinol, the inhibitor of xanthine oxidase, on reperfused ischemic skeletal muscles by observing the ultrastructural changes of the muscle fibers. A total of 48 healthy Sprague-Dawley rats weighing from 200 g to 250 g were used as experimental animals. Under urethane(3.0mg/kg., IP) anesthesia, lower abdominal incision was done and the left common iliac artery were ligated by using vascular clamp for 1, 2 and 6 hours. The left rectus femoris muscles were obtained at 6 hours after the removal of vascular clamp. In the allopurinol pretreated group, 50mg/kg of allopurinol was administered once a day for 2 days and before 2 hours of ischemia. The specimens were sliced into $1mm^3$ and prepared by routine methods for electron microscopic observations. All preparations were stained with uranyl acetate and lead citrate, and then observed with Hitachi -600 transmission electron microscope. The results were as follows: 1. In 1 hour ischemia/6 hours reperfused rectus femoris muscles of rats, decreased glycogen particles and electron density of mitochondrial matrix and dilated terminal cisternae are seen. In 2 hours ischemia/6 hours repersed rectus femoris muscles of rats, mitochondria with electron lucent matrix, irregularly dilated triad and spheromembranous bodies are observed. In 6 hours ischemia/6 hours reperfused rectus femoris muscles of rats, irregularly arranged myofibrils, and many spheromembranous bodies, fat droplets and lysosome are seen. 2. In 1 hour ischemia/6 hours reperfused rectus femoris muscles of rats pretreated with allopurinol, decreased glycogen particle and dilated cisternae of sarcoplasmic reticulum and triad are observed. In 2 hours ischemia/6 hours reperfused rectus femoris muscles of rats pretreated with allopurinol decreased electron density of mitochondrial matrix and spheromembranous bodies are seen. In 6 hours ischemia/6 hours reperfused rectus femoris muscles of rats pretreated with allopurinol, mitochondria with electron lucent matrix, spheromembranous bodies and dilated cisternae of sarcoplasmic reticulum and terminal cistern are observed. The results suggest that the allopurinol attenuates the damages of the skeletal muscles of rats during ischemia and reperfusion.

• The Korean Journal of Pharmacology
• /
• v.32 no.1
• /
• pp.31-37
• /
• 1996

The protective effect of 'ischemic preconditioning (IP)'on ischemia-reperfusion injury of heart has been reported in various animal species, but the mechanism is unclear. In an attempt to elucidate the mechanism of IP, we examined the effects of blockers against adenosine and protein kinase C in preconditioned heart of rat. The hearts perfused with oxygen-saturated Krebs-Henseleit solution by Langendorff method were exposed to 30 min global ischemia followed by 20 min reperfusion. IP was performed with three episodes of 5 min ischcmia and 5 min reperfusion just before ischemia-reperfusion. IP prevented the depression of contractile function and the myocardial contracture in the ischemic-reperfused heart and reduced the release of lactate dehydrogenase during the reperfusion period. Polymyxin B, chelerythrine and colchicine, PKC inhibitors, attenuated almost completely the anti-ischemic effect of IP, while adenosine receptor antagonists did not. These results indicate that PKC may be a crucial intracellular mediator in anti-ischemic action of IP in ischemic-reperfused rat heart, while adenosine may not be involved in the mechanism of IP.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.20 no.1
• /
• pp.98-102
• /
• 2006

The present stuby was carried out to determine if Radix Glycyrrhizae extract exerts beneficial effect against the ischemia-induced acute renal failure in rabbits. Radix Glycyrrhizae was known to reinforce the function of the spleen and replenish Qi, remove heat and counteract toxicity, dispel phlegm and relieve cough, alleviate spasmodic pain, and to moderate drug actions. It's indications are weakness of the spleen and the stomach marked by lassitude and weakness; cardiac palpitation and shortness of breath; cough with much phlegm; spasmodic pain in the epigastrium, abdomen and limbs; carbuncles and sores. It is often used for reducing the toxic or drastic actions of other drugs. Rabbits were treated with Radix Glycyrrhizae extract via i.v., followed by renal ischemia/reperfusion. Fractional excretion of glucose and phosphate, lipid peroxidation and light microscopy were done to evaluate the beneficial effect of Radix Glycyrrhizae extract on ischemia/reperfusion induced acute renal failure. Renal ischemia/reperfusion caused increase of fractional excretion of glucose and phosphate increased in ischemia-induced animals, which was partially prevented by Radix Glycyrrhizae extract treatment. Ischemia/reperfusion increased lipid peroxidation, which was prevented by Radix Glycyrrhizae extract administration. And the beneficial effect of Radix Glycyrrhizae extract on ischemia/reperfusion induced kidney injury was shown through the light micrographic observation. These results indicate that lipid peroxidation plays a critical role in ischemia-induced acute renal failure. Radix Glycyrrhizae extract exerts the protective effect against acute renal failure induced by renal ischemia/reperfusion.