OBJECTIVE To evaluate the effects of flavonoids from Xindakang(Hippophae Fructus flavone)on myocardial systolic and diastolic functions of isolated frog hearts and explore the possible mechanism,and provide experiment...OBJECTIVE To evaluate the effects of flavonoids from Xindakang(Hippophae Fructus flavone)on myocardial systolic and diastolic functions of isolated frog hearts and explore the possible mechanism,and provide experimental basis for improving the effect and efficacy of Xindakang on cardiac function.METHODS The isolated frog heart perfusion specimens were prepared by Yagi′s method,and the effects of different concentrations of Xindakang on myocardial contractility(0.0125,0.025,0.05,0.1 and 0.2 g·L^(-1)),heart rate and cardiac output of isolated frog heart were studied.Acetylcholine,atropine and epinephrine were administered successively to analyze the effects of Xindakang on cardiac systolic function of isolated frogs under the action of different drugs,and compared with propranolol.The effect of extracellular calcium ion concentration on the action of Xindakang was studied by using low calcium concentration,high calcium concentration and normal Ren′s solution.To study the effect and possible mechanism of Xindakang on cardiac systolic function of frog.RESULTS The concentration of Xindakang in the range of 0.0125-0.1 g·L^(-1)could weaken the contractility of isolated frog heart and increase the concentration of Xindakang.The inhibitory effect of Xindakang on contractility of isolated frog heart was enhanced,and showed obvious dose-effect relationship.Cardiac output was significantly decreased by Xindakang(P<0.01),slow heart rate(P<0.05);M receptor blocker atropine could not antagonize the contractile effect of Xindakang,and Xindakang could not completely antagonize the contractile effect of adrenalin.Xindakang could inhibit the isolated frog heart in low calcium concentration,high calcium concentration and normal Ren′s solution,and increased with the increase of extracellular calcium concentration(P<0.01).CONCLUSION Xindakang has inhibitory effect on isolated frog heart,which may be achieved by blocking the calcium channel on myocardial cell membrane and reducing the calcium concentration in myocardial cells.展开更多
Objective Levosimendan,a new calcium ion sensitizer,is currently used in the treatment of heart failure and as an option for patients with injury to the left heart or at high risk for surgery. The study tried to evalu...Objective Levosimendan,a new calcium ion sensitizer,is currently used in the treatment of heart failure and as an option for patients with injury to the left heart or at high risk for surgery. The study tried to evaluate the effects of levosimendan and ulinastain for protecting myocardium from ischemia-reperfusion (I / R) injury to展开更多
The effect of U50488, a selective K-opioid receptor agonist, on cardiac rhythm in the isolated perfused rat heart and intracellular calcium ([Ca2+] i) in the single ventricular myocyte were studied. The results showed...The effect of U50488, a selective K-opioid receptor agonist, on cardiac rhythm in the isolated perfused rat heart and intracellular calcium ([Ca2+] i) in the single ventricular myocyte were studied. The results showed that U50488 can induce arrhythmias dose-dependently in the isolated perfused rat heart and increase [ Ca2 + ] i in the single ventricular myocyte. The effect of U50488 can be blocked by a selectivek-receptor antagonist, nor-binaltorphimine. The arrhythmogenic effects and the increase of [ Ca2+]i induced by U50488 were blocked by U73122, neomycin and streptomycin, which are selective phospolipase C inhibitors, but not by U73433, the inactive structural analog of U73122. These results demonstrated that the arrhythmogenic effect of cardiac K-receptor is due to activation of phosphoinositol/Ca2+ pathway.展开更多
Background The maintenance of heart viability is important for heart transplantation. Currently, heart preservation is limited to 6 hours of cold ischemic storage. This study explored a new heart preservation method u...Background The maintenance of heart viability is important for heart transplantation. Currently, heart preservation is limited to 6 hours of cold ischemic storage. This study explored a new heart preservation method under a high-pressured mixed gas chamber. Methods C57BL/6 male mice were used to establish the model of mice cervical heterotopic heart transplantation. Adult donor mice were randomly divided into three groups subjected to naive operation （Group A）, standard control （Group B） and experimental control （Group C）. The recipient mice were randomly divided into two groups subjected to standard control and experimental control. Group A： hearts were isolated; Group B： hearts were isolated and preserved in HTK solution at 4 ℃ for 8 h and transplanted; Group C： hearts were isolated and preserved in high pressured gas （PO2：3200 hPa ＋ PCO： 800 hPa = 4000 hPa） at 4 ℃ for 8h and transplanted. After transplantation, the state of re-beating and cardiac function were observed for Group B and C. At 24 h after transplantation, samples were collected for HE staining, cardiac cell apoptosis detection by Tunnel staining and analysis of tumor necrosis factor α （TNF-α）, interleukin-1β （IL-1β）, interleukin-6 （IL-6） and interleukin-10 （IL-10） by reverse transcriotion-polymerase chain reaction （RT-PCR）. Results In group C, 15 transplanted hearts were re-beat, while only 6 in Group B. The re-beating rate in Group C was significantly higher than Group B [75.0%（15/20） vs. 30.0%（6/20） ,P = 0.01]. The time of re-beating was significantly different between Group B, and C [（352.35 ± 61.07）s vs. （207.85 ± 71.24） s, P 〈 0.011. HE staining showed that pathologic changes such as ceil edema and inflammatory cell infiltration were more obvious in Group B and C than in Group A, but less obvious in Group C compared with Group B. Tunnel staining showed that Group B had more obvious apoptosis than Group A and C. RT-PCR results showed significant increase of TNF-α, IL-1β and IL-6 expression in Group B than Group C （P 〈 0.01, the expression of IL-10 was higher in Group C than that in Group B. Conclusion Highpressured mixed gas （PO2：3200 hPa ＋ PCO： 800 hPa = 4000 hPa） preservation can reduce cold ischemia and reperfusion injury of donor heart, therefore to maintain myocardial viability and prolong preservation time of donor heart.展开更多
The model of this test was set up according to Langendoff isolated heart reperfusion mechanics. The experimental research was designed to observe the protective effects on ischemic andreperfuslon myocardial tissue by ...The model of this test was set up according to Langendoff isolated heart reperfusion mechanics. The experimental research was designed to observe the protective effects on ischemic andreperfuslon myocardial tissue by using ST. Thomas cardioplegic solution containing selenium andmagnesium. We conclude that using cold crystallold cardioplegic solution containing Se'+, Mg' 4 canobviously reduce ischemic and reperfusion myocardlal injury and bas an advantage of recovering myocardial runctlon after operation by observing the content or lactic dehydrogenase (LDH); creatineI,kasphoklnase CK in the coronary vessel's sinus reflux solutlonl glutatblone peroxldase (GPX); suI,eroxlde dismutase (SOD); maloydladehyde (MDA ) I Se4+ .Mg'+ .Ca'+ and cia-nging or myocardialultrastructure.展开更多
Myocardial ischemia is the most common and primary cause of myocardium damage. Numerous conventional techniques and methods have been developed for ischemia and reperfusion studies. However, because of damage to the h...Myocardial ischemia is the most common and primary cause of myocardium damage. Numerous conventional techniques and methods have been developed for ischemia and reperfusion studies. However, because of damage to the heart sample, most of these techniques can not be used to continuously monitor the full dynamic course of the myocardial metabolic pathway. The nuclear magnetic resonnance (NMR) surface coil technique, which overcomes the limitations of conventional instrumentation, can be used to quantitatively study every stage of the perfused heart (especially after perfusion stoppage) continuously, dynamically, and without damage under normal or designed physiological conditions at the molecular level. In this paper, 31 P NMR was used to study the effects of ischemia and hypoxia on isolated perfused hearts. The results show that complete hypoxia caused more severe functional damage to the myocardial cells than complete ischemia.展开更多
Direct effects of a high-dose aprotinin on the normally perfused hearts and the myocardial protection after ischemia and reperfusion were investigated in an isolated working rat heart model. In trial I, hearts had no ...Direct effects of a high-dose aprotinin on the normally perfused hearts and the myocardial protection after ischemia and reperfusion were investigated in an isolated working rat heart model. In trial I, hearts had no ischemia and were perfused with either K-H solution or the K-H solution containing aprotinin (200KIU/ml) for 55 min. No statistically significant difference was observed in hemodynamics betweem the two groups. In trial Ⅱ, hearts were exposed to 150 minperiod of global ischemia at 15℃ with 4℃ multidose St. Thomas'Ⅱ solution (STS). The control group I received norma1 K-H solution; the group Ⅱ was treated with the solution with aprotinin added. The group, was similar to the group Ⅰ and received the STS enriched with aprotinin. On reperfusion, the recovery of hearts in group, was significantly better than those of the group Ⅰand Ⅱ, as reflected by better hemodynamics and myocardial oxygen consumption,lower level myocardial enzymes, higher myocardial ATP levels and milder myocardial ultrastructural injury. There was no difference between the group Ⅰand Ⅱ. These results suggest that the aprotinin at a dose of 200 KIU/ml has no harmful effects on normally perfused hearts and has a marked myocardial protective effect on the prolonged myocardial ischemia when used in cold crystalloid cardioplegia.展开更多
基金Natural Science Foundation of Tibet Autonomous Region(2015ZR-13-16)。
文摘OBJECTIVE To evaluate the effects of flavonoids from Xindakang(Hippophae Fructus flavone)on myocardial systolic and diastolic functions of isolated frog hearts and explore the possible mechanism,and provide experimental basis for improving the effect and efficacy of Xindakang on cardiac function.METHODS The isolated frog heart perfusion specimens were prepared by Yagi′s method,and the effects of different concentrations of Xindakang on myocardial contractility(0.0125,0.025,0.05,0.1 and 0.2 g·L^(-1)),heart rate and cardiac output of isolated frog heart were studied.Acetylcholine,atropine and epinephrine were administered successively to analyze the effects of Xindakang on cardiac systolic function of isolated frogs under the action of different drugs,and compared with propranolol.The effect of extracellular calcium ion concentration on the action of Xindakang was studied by using low calcium concentration,high calcium concentration and normal Ren′s solution.To study the effect and possible mechanism of Xindakang on cardiac systolic function of frog.RESULTS The concentration of Xindakang in the range of 0.0125-0.1 g·L^(-1)could weaken the contractility of isolated frog heart and increase the concentration of Xindakang.The inhibitory effect of Xindakang on contractility of isolated frog heart was enhanced,and showed obvious dose-effect relationship.Cardiac output was significantly decreased by Xindakang(P<0.01),slow heart rate(P<0.05);M receptor blocker atropine could not antagonize the contractile effect of Xindakang,and Xindakang could not completely antagonize the contractile effect of adrenalin.Xindakang could inhibit the isolated frog heart in low calcium concentration,high calcium concentration and normal Ren′s solution,and increased with the increase of extracellular calcium concentration(P<0.01).CONCLUSION Xindakang has inhibitory effect on isolated frog heart,which may be achieved by blocking the calcium channel on myocardial cell membrane and reducing the calcium concentration in myocardial cells.
文摘Objective Levosimendan,a new calcium ion sensitizer,is currently used in the treatment of heart failure and as an option for patients with injury to the left heart or at high risk for surgery. The study tried to evaluate the effects of levosimendan and ulinastain for protecting myocardium from ischemia-reperfusion (I / R) injury to
文摘The effect of U50488, a selective K-opioid receptor agonist, on cardiac rhythm in the isolated perfused rat heart and intracellular calcium ([Ca2+] i) in the single ventricular myocyte were studied. The results showed that U50488 can induce arrhythmias dose-dependently in the isolated perfused rat heart and increase [ Ca2 + ] i in the single ventricular myocyte. The effect of U50488 can be blocked by a selectivek-receptor antagonist, nor-binaltorphimine. The arrhythmogenic effects and the increase of [ Ca2+]i induced by U50488 were blocked by U73122, neomycin and streptomycin, which are selective phospolipase C inhibitors, but not by U73433, the inactive structural analog of U73122. These results demonstrated that the arrhythmogenic effect of cardiac K-receptor is due to activation of phosphoinositol/Ca2+ pathway.
基金supported by Major International(Regional)Joint Research Project of Ministry of Science and Technology of China(No.2010DFA32660)
文摘Background The maintenance of heart viability is important for heart transplantation. Currently, heart preservation is limited to 6 hours of cold ischemic storage. This study explored a new heart preservation method under a high-pressured mixed gas chamber. Methods C57BL/6 male mice were used to establish the model of mice cervical heterotopic heart transplantation. Adult donor mice were randomly divided into three groups subjected to naive operation （Group A）, standard control （Group B） and experimental control （Group C）. The recipient mice were randomly divided into two groups subjected to standard control and experimental control. Group A： hearts were isolated; Group B： hearts were isolated and preserved in HTK solution at 4 ℃ for 8 h and transplanted; Group C： hearts were isolated and preserved in high pressured gas （PO2：3200 hPa ＋ PCO： 800 hPa = 4000 hPa） at 4 ℃ for 8h and transplanted. After transplantation, the state of re-beating and cardiac function were observed for Group B and C. At 24 h after transplantation, samples were collected for HE staining, cardiac cell apoptosis detection by Tunnel staining and analysis of tumor necrosis factor α （TNF-α）, interleukin-1β （IL-1β）, interleukin-6 （IL-6） and interleukin-10 （IL-10） by reverse transcriotion-polymerase chain reaction （RT-PCR）. Results In group C, 15 transplanted hearts were re-beat, while only 6 in Group B. The re-beating rate in Group C was significantly higher than Group B [75.0%（15/20） vs. 30.0%（6/20） ,P = 0.01]. The time of re-beating was significantly different between Group B, and C [（352.35 ± 61.07）s vs. （207.85 ± 71.24） s, P 〈 0.011. HE staining showed that pathologic changes such as ceil edema and inflammatory cell infiltration were more obvious in Group B and C than in Group A, but less obvious in Group C compared with Group B. Tunnel staining showed that Group B had more obvious apoptosis than Group A and C. RT-PCR results showed significant increase of TNF-α, IL-1β and IL-6 expression in Group B than Group C （P 〈 0.01, the expression of IL-10 was higher in Group C than that in Group B. Conclusion Highpressured mixed gas （PO2：3200 hPa ＋ PCO： 800 hPa = 4000 hPa） preservation can reduce cold ischemia and reperfusion injury of donor heart, therefore to maintain myocardial viability and prolong preservation time of donor heart.
文摘The model of this test was set up according to Langendoff isolated heart reperfusion mechanics. The experimental research was designed to observe the protective effects on ischemic andreperfuslon myocardial tissue by using ST. Thomas cardioplegic solution containing selenium andmagnesium. We conclude that using cold crystallold cardioplegic solution containing Se'+, Mg' 4 canobviously reduce ischemic and reperfusion myocardlal injury and bas an advantage of recovering myocardial runctlon after operation by observing the content or lactic dehydrogenase (LDH); creatineI,kasphoklnase CK in the coronary vessel's sinus reflux solutlonl glutatblone peroxldase (GPX); suI,eroxlde dismutase (SOD); maloydladehyde (MDA ) I Se4+ .Mg'+ .Ca'+ and cia-nging or myocardialultrastructure.
文摘Myocardial ischemia is the most common and primary cause of myocardium damage. Numerous conventional techniques and methods have been developed for ischemia and reperfusion studies. However, because of damage to the heart sample, most of these techniques can not be used to continuously monitor the full dynamic course of the myocardial metabolic pathway. The nuclear magnetic resonnance (NMR) surface coil technique, which overcomes the limitations of conventional instrumentation, can be used to quantitatively study every stage of the perfused heart (especially after perfusion stoppage) continuously, dynamically, and without damage under normal or designed physiological conditions at the molecular level. In this paper, 31 P NMR was used to study the effects of ischemia and hypoxia on isolated perfused hearts. The results show that complete hypoxia caused more severe functional damage to the myocardial cells than complete ischemia.
文摘Direct effects of a high-dose aprotinin on the normally perfused hearts and the myocardial protection after ischemia and reperfusion were investigated in an isolated working rat heart model. In trial I, hearts had no ischemia and were perfused with either K-H solution or the K-H solution containing aprotinin (200KIU/ml) for 55 min. No statistically significant difference was observed in hemodynamics betweem the two groups. In trial Ⅱ, hearts were exposed to 150 minperiod of global ischemia at 15℃ with 4℃ multidose St. Thomas'Ⅱ solution (STS). The control group I received norma1 K-H solution; the group Ⅱ was treated with the solution with aprotinin added. The group, was similar to the group Ⅰ and received the STS enriched with aprotinin. On reperfusion, the recovery of hearts in group, was significantly better than those of the group Ⅰand Ⅱ, as reflected by better hemodynamics and myocardial oxygen consumption,lower level myocardial enzymes, higher myocardial ATP levels and milder myocardial ultrastructural injury. There was no difference between the group Ⅰand Ⅱ. These results suggest that the aprotinin at a dose of 200 KIU/ml has no harmful effects on normally perfused hearts and has a marked myocardial protective effect on the prolonged myocardial ischemia when used in cold crystalloid cardioplegia.
