Effects of nitric oxide on mitochondrial damage caused by exogenous calcium

AIM: To study the effects of nitric oxide (NO) on mitochondrial damage caused by exogenous calcium. METHODS: Normal myocardial mitochondria were divided into three groups; L-arginine control group (CG), Ca^2＋-damaged group (DG) and L-NAME-preserved group (PG). Mitochondria of all groups were incubated at 30 ℃ with reaction medium containing 20 μmol/L EDTA, 100 μmol/L CaCl₂ and 1 μmol/L L-NAME with 100 μmol/L CaCl₂ respectively. Then the NO₂^-/NO₃^- contents, mitochondrial viability and membrane potential were investigated. RESULTS: The NO₂^-/NO₃^- contents of DG was obviously higher than that of CG and PG, meanwhile, there was no obvious difference between CG and PG. Mitochondrial viability and membrane potential of DG were significantly lower than that of CG and PG, and negatively related to NO^-₂/NO^-₃ contents (r=-0.5297, P＜0.01; r=-0.6041, P＜0.01). But, the mitochondrial viability and membrane potential of PG were still lower than that of CG. CONCLUSION: Exogenous calcium could activate mitochondrial nitric oxide synthase resulting in NO production and the latter play an important role in decreasing mitochondrial viability and membrane potential.     

Progress in mitochondrial nitric oxide synthase

Nitric oxide (NO) is an intra- and intercellular messenger with a broad spectrumof activities in the central nervous system, cardiovascular and immune systems. Mitochondrial nitric oxide synthase (mt-NOS), which might be a new form of NOS in mitochondria, has been discovered to be active in the regulation ofmitochondrial respiration, energy metabolism and many pathophysiological processes.In this review, the location, properties, physiological and pathophysiological significance of mtNOS were summarized.     

Effects of nitric oxide and inducible nitric oxide synthase on process of atherosclerosis

AIM：To explore the dynamic changes of nitric oxide and inducible nitric oxide synthase during the process of atherosclerosis, and to analyze their influence on the formation of atherosclerosis. METHODS：SD rats (n=60) were randomly divided into control group and atherosclerosis group (30 rats in each group). Atherosclerosis model was induced by feeding high-fat diet and vitamin D3. The values of blood biochemical were analyzed enzymatically using bioMérieux kit. The concentration of serum nitric oxideing was detected by a colorimetric method. The success of atherosclerosis modeling was determined by pathological examination. The protein expression of inducible nitric oxide synthase in atherosclerotic plaque was detected by the method of immunohistochemistry. RESULTS：The atherosclerosis model was successfully established in 90 d. The concentration of serum nitric oxide gradually decreased in atherosclerosis group, and a significant difference among groups was observed. Atherosclerosis index was positively correlated with calcium ion, and negatively correlated with nitric oxide. The protein expression of inducible nitric oxide synthase in the atherosclerotic plaque after 90 d was found. CONCLUSION:The protein expression of inducible nitric oxide synthase in the plaque area of aorta increases and the concentration of serum nitric oxide decreases with the process of atherosclerosis. The anti-atherosclerosis role of nitric oxide is gradually decreased.     

Effects of folic acid on antioxidant enzyme,nitric oxide synthase and nitric oxide in ovariectomized rats

AIM: To observe the effects of folic acid (FA) on antioxidant enzyme, nitric oxide synthase (NOS) and nitric oxide (NO) in ovariectomized (OVX) rats.METHODS: Forty three-month-old female SD rats were randomly divided into 5 groups: sham group, OVX group, diethylstilbestrol group (0.03 mg·kg^-1·d^-1), low-dose FA group (5 mg·kg^-1·d^-1) and high-dose FA group (20 mg·kg^-1·d^-1). Gastric gavage started 1 week after operation and lasted for 10 weeks. The rats in sham group and OVX group were given distilled water instead of FA as controls. At the end of the 10th week, the L₅ vertebra and right femur were removed for determination of bone mineral density (BMD). The bone homogenates were made using the L₃ and L₄ vertebrae. The levels of the total antioxidant capacity (TAC), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), NOS and NO were detected in plasma and bone homogenates.RESULTS: Compared with sham group, the BMD levels in L₅ vertebra and right femur and the levels of GSH-Px and NO in the plasma were all decreased. The levels of TAC, GSH-Px, NOS and NO in the bone homogenates were also decreased, while the MDA concentration was increased in OVX group (all P < 0.01). Compared with OVX group, the levels of TAC, GSH-Px, NOS, NO and BMD of the L₅ vertebra and right femur were all increased, while the MDA concentration was decreased in high-dose FA group (all P < 0.01). CONCLUSION: In female SD rats, ovariectomy leads to a significant reduction of antioxidant enzyme, NOS and NO levels. Oxidative stress is possibly involved in the development of osteoporosis. Protection against osteoporosis by high-dose FA may be linked to improvement of antioxidant enzyme activity, the levels of NOS and NO as well as a reduction of oxidative stress in ovariectomized rats.     

Effects of nitric oxide inhalation on nitric oxide synthase and endothelin-1 in patients with hypoxic pulmonary hypertension

AIM: To investigate the effects of nitric oxide (NO) inhalation on nitric oxide synthase (NOS) and endothelin-1 (ET-l) of patients with hypoxic pulmonary hypertension. METHODS: Examined 13 pulmonic blood samples to determine the concentration of NOS in leukocyte and ET-1 in plasma before NO inhalation, 30 minutes after inhalation, 2 and 12 hours after stopping of inhalation respectiviy. RESULTS: The values taken before inhalation was NOS (0.70 ± 0.21 )mol/min·mg^-1, ET-1 (78.89 ± 46.59) Pmol/L; 30 minutes after inhalation (0.74±0.14)mol/min·mg^-1, ET-1 (88.27 ± 45.41 )pmol/L; 2 hours after stopping of inhalation NOS (0.64 ± 0.22)mol/min·mg-1, ET-1 (80.76±42.66)pmol/L; and 12 hours after stopping of inhalation NOS (0. 63± 0. 17)mol/min.mg-1, ET-1(61.07±29.44)pmol/L. NO significant difference was found in the values of NOS and ET- 1 before and after inhalation, P＞ 0.05. CONCLUSION: The effects of NO inhalation on NOS and ET-l in patients with hypoxic pulmonary hypertension are not significant according to the above investigation.     

Effects of external counterpulsation on nitric oxide system in myocardial infarction canines

AIM:To investigate the effects of external counterpulsation(ECP)on nitric oxide(NO)and nitric oxide synthase(NOS)and the expression of NOS gene in myocardial infarction canines.METHODS:Nineteen healthy dogs were randomly divided into three groups ie.controls, ischemia group, ischemia and ECP group.Serum NO concentrations and myocardium NO levels and NOS specific activity were determined by modified nitrate reductase method.T he protein synthesis of sub-type NOS including inducible NOS(iNOS)and endothelial NOS(eNOS)of myocardial tissue were also determined by immunohistochemical method.The constitutive NOS(cNOS)mRNA was measured via in situ hybridization.RESULTS:120 and 180 minutes after the ligat ing of LAD, serum NO concentration in ECP groups were higher than those in ischemic groups(P<0.05).The NO levels and NOS specific activity in myocardium of ischemic dogs were lower than those in controls and ECP group(P<0.05).Protein synthesis of iNOS increased and that of eNOS decreased in ischemic myocardium.But ECP could control the protein synthesis of iNOS, and increase that of eNOS.Further studies showed that the expression of cNOS mRNA decreased in ischemic myocardial tissue, ECP might promote the expression of it and regulate NOS in the gene level.CONCLUSION:The results suggested that it was one of the most important mechanisms through raising the NO levels to protect ischemic myocardium in ECP.     

Role of nitric oxide in aortic contractile function of renal hypertensive rats

AIM:To investigate the changes of aortic contractile function in renal hypertension with two-kidney, one-clip (2K1C) rats and its interrelation with nitric oxide (NO). METHODS:Animals were divided into 5 groups, sham operation group, 2K1C group, captopril group, L-arginine group and L-NAME group. At 4th week after operation, isometric tension changes of aortic rings were recorded, aortric cGMP content were also measured. RESULTS:Phenylephrine, acetylcholine, angiotensin Ⅱ and high potassium chloride solution-induced contraction was significantly increased, and aortric cGMP content was lowered in aortic rings from 2K1C rats compared with rings from sham rats. These changes were abolished in 2K1C rats treated with captopril. L-arginine partially reversed the change of aortic contractibility of 2K1C rats, and elevated aortic cGMP content. In 2K1C rats treated with nitric oxide synthase inhibitor L-NAME, aortric cGMP content were decreased further, but phenylephrine-induced contractile response were unaffected. After blockade of NO production with L-NAME, the maximal responses of aortric rings relaxation to sodium nitroprussidum were not significantly different in all five groups. CONCLUSION:These results indicate that the deficiency of nitric oxide production and the increase in the contractive factor in vascular tissue may contribute to changes in aortic contractile function of 2K1C rats.     

Effects of aspirin on production of nitric oxide and inducible nitric oxide synthase mRNA expression under inflammatory conditions in human vascular endothelial cells

AIM: To explore the effect of aspirin on inducible nitric oxide synthesis and gene expression under inflammation in endothelial cells. METHODS:Using NADPH, Griess methods and RT-PCR, the activity of isozymes of NO synthase (NOS), nitric oxide (NO) level, and iNOS mRNA expression were examined respectively. Also, the lactate dehydrogenase (LDH) release rate, malondialdehyde (MDA) content and cell viability were measured. RESULTS: Aspirin (3 mmol/L) reduced inducible NO production and NOS activity(P＜0.05), caused a significant decrease in LDH release rate and MDA content with a further increase in cell viability. Aspirin inhibited inducible NO excretion and alleviated the damage caused by NO in a concentration-dependent manner. However,aspirin had no effect on basal NO levels in the absence of stimulation by inflammatory factor. On the other hand, under middle concentration (＜10 mmol/L), aspirin was able to reduce enzymatic activity of NOS and protein expression by increasing the stability of iNOS mRNA. In contrast, at high concentration (20 mol/L), aspirin could decrease the stability of iNOSmRNA. Sodium salicylate and indomethacin did not inhibit inducible NO production. CONCLUSION:Aspirin could significantly inhibit inducible NO production in vascular endothelial cells during inflammation.     

Effects of nitric oxide synthase inhibitors on focal cerebral ischemic injury in rats

AIM:To observe the effects of nitric oxide and different isoforms of nitric oxide synthase inhibitors on the focal cerebral ischemic injury in rats. METHODS:After the rat model of focal cerebral ischemia were established with middle cerebral artery occlusion (MCAO), aminoguanidine(AG)and N^G-nitro-L-arginine(L-NA )were administrated and the cerebral infarct size, NO production,MDA content, nitric oxide synthase(NOS) and SOD activities in the focal ischemic brain tissues were examined. RESULTS:AG could significantly attenuate the focal cerebral ischemic injury, and L-NA had a protective effect when it was administrated at 1 h,6 h but not at 3 h after surgery.CONCLUSION:Cerebral ischemic injury could be attenuated by both selective and nonselective inhibition of NOS.     

Effects of nitric oxide on hepatic encephalopathy in cirrhotic rats induced by LPS

AIM: To investigate the effects of nitric oxide (NO) on hepatic encephalopathy in cirrhotic rats induced by LPS. METHODS: The cirrhotic model of rats was established by complex pathogeny. Since the end of the 8 th week, the rats were intragastrically-infused with 0.9% salt, L-arginine(L-arg) and LNNA respectively for 2 weeks.The hepatic encephalopathy in cirrhotic rats were induced by 3 mg/kg LPS (ip) 4 hours before the rats were sacrificed. RESULTS: The normal behaviors and electroencephalograph were appeared in L-arg group. LNNA group showed hepatic encephalopathy. The content of NO₂^-/NO₃^- of brain tissue was markedly higher in L-arg group than LNNA group(P<0.05), but the content of histamine in brain tissue was lower in L-arg group than LNNA group(P<0.05). There was a negative correlation between the content of histamine in brain tissue and the content of NO₂^-/NO₃^- of brain tissue. CONCLUSION: NO can prevent hepatic encephalopathy in cirrhotic rats induced by LPS.     

Insulin-like growth factor I protects neonatal rat cardiomyocytes from apoptosis through improvement of mitochondrial function

AIM：To investigate whether mitochondrial mechanism is involved in the anti-apoptotic effect of insulin-like growth factor I (IGF-I) on cardiomyocytes. METHODS：Primary neonatal rat cardiomyocytes (NRCMs) were cultured and treated with 200 μmol/L hydrogen peroxide (H2O2) to induce apoptosis. Kruppel-like factor 9 (KLF9)-specific siRNA was transfected into the cells by Lipofectamine 2000. The mitochondrial function was measured by JC-1 mitochondrial membrane potential (MMP) assay. The mitochondrial morphology was observed by transmission electron microscopy. Myocardial cell apoptosis was detected by Annexin V-FITC/PI dual staining, caspase-3 activity assay, DNA-ladder analysis and Hoechst 33258 staining. RESULTS：The apoptosis of NRCMs was induced by H2O2, with MMP decreased by (24.0±1.6)% compared with control group. The fall rates of MMP in IGF-I group and KLF9 siRNA group were (18.3±1.2)% and (15.2±1.2)%, respectively (both P<0.01 vs H2O2 group), and improved mitochondrial morphology, decreased caspase-3 activity, attenuated DNA fragmentation and reduced apoptotic bodies were also observed in these two groups. The apoptotic rates of NRCMs in IGF-I group and KLF9 siRNA group were (22.4±4.2)% and (32.5±3.5)%, respectively, both lower than that in H2O2 group ［(42.5±1.8)%, P<0.01］. The anti-apoptotic effect of KLF9 silencing on NRCMs was consistent with that of IGF-I treatment. CONCLUSION：IGF-I protects NRCMs from apoptosis through down-regulating KLF9 expression and improving mitochondrial function.     

Effects of atorvastatin on nitric oxide,endothelin-1 and myocardial function in a rabbit model of acute myocardial infarction and reperfusion

AIM: To evaluate the effects of atorvastatin on nitric oxide(NO), endothelin-1(ET-1)and myocardial no-reflow in a rabbit model of acute myocardial infarction and reperfusion(AMI/R). METHODS: Twenty-four rabbits were randomized into 3 groups: 8 in AMI/R group, 8 in atorvastatin-treated group(5 mg·kg-1·d-1)and 8 in sham-operated group. Animals in the former two groups were subjected to 60 min of coronary occlusion followed by 120 min of reperfusion. Data on haemodynamics were collected. NO in blood sample, and in normal, and in infarcted reflow and no-reflow myocardium were evaluated respectively by nitrate reductase method. The levels of ET-1 in blood sample, and in normal, infarcted reflow and no-reflow myocardium were determined by radioimmunoassay. RESULTS: (1)Compared to the baselines, the heart rate(HR), systolic blood pressure(SBP), diastolic blood pressure(DBP), left ventricular systolic pressure(LVSP), maximal rate of increase and decline in left ventricular pressure(±dp/dtmax)and cardiac output(CO)in AMI/R and atorvastatin-treated groups were significantly declined, whereas left ventricular end-diastolic pressure(LVEDP)was increased after 60 min of coronary occlusion and 120 min of reperfusion(P<0.05 or P<0.01). However, in atorvastatin-treated group, LVSP, LVEDP, ±dp/dtmax and CO at the time point of 120 min of reperfusion recovered more significantly than those at the time point of 60 min of coronary occlusion(P<0.01), which was more significant than those in AMI/R group(P<0.05 or P<0.01). Compared to AMI/R group, the SBP and DBP were significantly heigher in atorvastatin-treated group(P<0.01).(2)In atorvastatin-treated group, the levels of ET-1 in blood sample were significantly lower than those in AMI/R group(P<0.01), and the levels of NO were significantly higher(P<0.01). Moreover, the levels of NO or ET-1 in infarcted reflow myocardium were significantly lower than that in AMI/R group(P<0.05 or P<0.01).(3)Atorvastatin could ameliorate myocardial function. CONCLUSION: Atorvastatin is effective in increasing NO and reducing ET-1 in blood plasma and local myocardium, and in protection of endothelial cells. Atorvastatin also has a beneficial effect on improving left ventricular function during acute myocardial infarction and reperfusion in rabbits.     

Changes of nitric oxide synthase and nitric oxide in lung of smoking rats

AIM:To observe the changes of iNOS and eNOS in lung tissue and NO in bronchoalveolar lavage fluid (BALF) in smoking rats.METHODS:80 Wistar rats were divided into control, smoking group, L-NIL group and L-NAME group (rats were exposed to smoke and injected (i.p.) with selective iNOS inhibitor L-NIL or NOS inhibitor L-NAME). iNOS and eNOS protein levels in whole lung were detected by immunohistochemical staining, and NOS mRNA was quantified using RT-PCR. In addition, NO₂^-/NO₃^- was determined using Griess assay.RESULTS:The expression of iNOS mRNA and protein in smoking rats increased, the expression of eNOS mRNA and eNOS protein decreased, and the total cell count and the level of NO₂^-/NO₃^-in BALF increased(P＜0.05). In vivo, L-NIL reduced the total cell count and NO₂^-/NO₃^- in BALF (P＜0.05), while L-NAME had no effect on them.CONCLUSION:Cigarette smoke increased expression of iNOS mRNA and protein and decreased expression of eNOS mRNA and protein. The large amount of NO generated by iNOS may amplify inflammation in lung tissue.     

Effects of hypoxia on endothelial nitric oxide synthase expression in cerebral artery endothelial cells

AIM: To investigate the molecular mechanism by which hypoxia affect the endothelial nitric oxide synthase (eNOS) expression in cerebral artery endothelial cells (CAECs). METHODS: Primary cultured porcine CAECs were exposed to hypoxia for 2 h, 6 h, 12 h, 24 h and 48 h. The eNOS mRNA level was determined by RT-PCR. The level of eNOS protein was detected by Western blotting. After specific PKC inhibitors BIM Ⅰ(1 μmol/L) and G6983 (1 μmol/L) were added, CAECs were exposed to hypoxia for 24 h. The effect of hypoxia on eNOS mRNA stability was analyzed after actinomycin D was added. RESULTS: After exposure to hypoxia for 2 h, the levels of eNOS mRNA and protein in CAECs were increased. The levels of eNOS mRNA and protein reached peak after 12 h of hypoxia (about 2.5 fold and 2.0 fold, respectively, compared to control), and remained at higher level even after 48 h of hypoxia. Moreover, hypoxia did not change the stability of eNOS mRNA. The specific PKC inhibitors BIM Ⅰ and G6983 attenuated significantly the effects of hypoxia on eNOS gene expression. CONCLUSION: These results suggest that hypoxia may enhance the expression of eNOS gene in CAECs through PKC signaling pathway, which might be one of the mechanisms of cerebral artery dilation and neuroprotection during cerebral hypoxia.     

Effects of hypoxia on levels of nitric oxide,endothelin-1 and inducible nitric oxide synthase mRNA expression in cultured human umbilical vein endothelial cells

AIM: To observe the effects of hypoxia on the levels of nitric oxide (NO), endothelin (ET-1) and the expression of inducible nitric oxide synthase (iNOS) mRNA in human umbilical vein endothelial cells (HUVECs), and further investigate the mechanism of hypoxic pulmonary hypertension. METHODS: On the basis of the HUVECs culture model, the methods of nitrate reductase and radioimmunoassay were used to determine the changes of NO and ET-1 in the medium secreted by HUVECs, and the expression of iNOS mRNA was analyzed by semi quantitative RT-PCR after exposure to hypoxia (3% O2) for 6, 12 or 24 h. RESULTS: The contents of NO2-/NO3- and ET-1 in hypoxia group in the medium was significantly higher than that in control group at different time points (P<0.05). Also, iNOS mRNA expression increased significantly (P<0.05). CONCLUSION: Hypoxia stimulates the release of NO and ET-1 from HUVECs, also induces iNOS-mRNA expression. The change of NO may be the result of iNOS mRNA upregulation induced by hypoxia.     

Changes in endogenous nitric oxide and effects of inhaled nitric oxide on pulmonary artery hypertension in chronically hypoxic rats

AIM: To investigate the role of nitric oxide (NO)in the development of chronically hypoxic pulmonary artery hypertension (PAH) and the hemodynamic effects of inhaled NO on pulmonary circulation. METHODS: 67 male adult SD rats were randomly divided into 7 groups: (1) control (n=9);(2) chronically intermitent hypoxia (CIH, 6 h/d, 7 d/w) 1 week(n=7); (3) CIH 2 weeks (n=11); (4) CIH 3 weeks (n=11); (5) CIH 1 week+L-NAME (NO synthase inhibitor, 30 mg/kg, by gavage, n=10); (6)CIH 3 weeks+L-Arg (NO precursor, 10 mg/kg, by gavage, n=9); (7) CIH 3 weeks+inhaled NO (0.0004% for 20 min, n=10) to determine the mean pulmonary artery pressure (MPAP), weigh the right ventricle (R) and ventricular segment plus left ventricle (S+L), and calculate R/(S+L) (g/g) and R/Wt (Wt: body weight, g/kg). RESULTS: 1.MPAP increased compared with control when CIH 1 week, reaching the highest when CIH 2 weeks; R/(S+L) and R/Wt also increased notably when CIH 1 week (P＜0.01); 2. The level of plasma NO₂^-/NO₃^- elevated significantly when CIH 2 weeks, but fell when CIH 3 weeks; the content of plasma ET-1(endothelin-1) also increased significantly. The level of plasma ET-1 correlated with R/(S+L) and R/Wt, r=0.43 and 0.46, respectively, both P＜0.01; 3. The level of plasma NO₂^-/NO₃^- droped 33.2 % (P＜0.01) after treatment with L-NAME, with R/(S+L) increasing 15.2 % (P＜0.05); 4. L-Arg decreased the MPAP 17.8 %(P＜0.01). CONCLUSION: The endogenous NO release increases at early stage (1-2 weeks) of chronic hypoxia, but falls at the prolonged stage; the elevated level of plasma ET-1 possibly plays an important role in remodeling of chronically hypoxic pulmonary vessels and ventricle; inhaled NO significantly decreases the chronically hypoxic PAH.     

Effects of diazoxide preconditioning on mitochondrial respiratory function and enzyme activity in rats

AIM: To investigate the effects of the selective mitochondrial ATP-sensitive K+ channels opener diazoxide on mitochondrial respiratory function and enzyme activity in isolated rat myocardium under ischemia/reperfusion.METHODS: Observation was made on rat hearts perfused with Langendorff apparatus.72 Sprague-Dawley (SD) rats were randomly divided into 4 groups: normal group (NOR),ischemia reperfusion (IR),diazoxide group (DIA) and 5-hydroxydecanoate (5-HD) antagonized diazoxide group (5HD-DIA).Hearts isolated from SD rats were mounted on a Langendorff apparatus and started with a 20 min perfusion for equilibration.NOR went on perfusion for another 100 min after equilibration.IR underwent 40 min global ischemia and followed by 30 min reperfusion after 30 min stabilization.DIA was administered with K-H solution containing diazoxide at concentration of 50 μmol/L for 10 min before ischemia and reperfusion.5HD-DIA was infused with 100 μmol/L 5-HD (a specific mitochondrial ATP sensitive K+ channel blocker) and the same procedure was carried out as DIA group.Hearts were taken down to extract mitochondrial at the end-equation,before ischemia and at the end-reperfusion for determination of mitochondrial respiratory function and the enzyme activity of mitochondria.RESULTS: At the end of reperfusion,mitochondrial respiratory function (mitochondrial respiratory control rate,P/O ratio and state 3 respiration) and mitochondrial enzyme activity (NADH oxidase,succinate oxidase and cytochrome C oxidase) in DIA group were better than those in IR group and 5HD-DIA group (P<0.05),but worse than those NOR group (P<0.01).No significant difference in all parameters was observed between IR and 5HD-DIA (P>0.05).CONCLUSION: Preconditioning with mitochondrial ATP sensitive potassium channel opener,diazoxide,protects rat heart mitochondria against ischemia-reperfusion injury.The mechanisms are involved in the safeguarding of respiratory function and activity of enzymes of respiratory chain.     

Effect of glycine liposomes on mitochondrial membrane potential and apoptosis in cultured cardiomyocytes

AIM: To observe the effect of glycine liposomes on the mitochondrial membrane potential and the apoptosis rate in cardiomyocytes induced by hypoxia/reoxygenation injury. METHODS: A cardiomyocyte injury model was established by using hypoxia/reoxygenation. DiOC6(3) as fluorescence molecular probe was used to detect the mitochondrial membrane potential in each group. The method of Annexin V associated with PI was used to detect the apoptosis ratio in each group. RESULTS: (1) The result of flow cytometry showed that the mitochondrial membrane potential of cardiomyocytes in H/R group was obviously lower than that in control group (P<0.01). The decrease in mitochondrial membrane potential in Gly-liposome group was the lowest, the percentage of cells about the part of hypofluorescence was (9.61±0.76)%, which was lower than that in glycine group (P<0.01). (2) The apoptosis rate of cardiomyocytes in H/R group was higher than that in control group (20.78±1.58)%,P<0.01. After the treatment of Gly-liposome, the apoptosis rate of cardiomyocytes was lower than that in glycine group (P<0.01). No difference in the apoptosis ratios between blank-liposome group and H/R group was observed(P>0.05).CONCLUSION: Glycine liposomes protect cultured cardiomyocytes against hypoxia/reoxygenation injury. Glycine liposomes produce the better protective effects than glycine.