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Objective:To evaluate the role of endoplasmic reticulum stress in myocardial ischemia-reperfusion (I/R) injury and the relationship with autophagy in rats.Methods:Thirty-six healthy adult male Sprague-Dawley rats, weighing 250-300 g, were divided into 3 groups ( n=12 each) using a random number table method: sham operation group (Sham group), myocardial I/R group (IR group), and endoplasmic reticulum stress inhibitor 4-PBA group (PBA group). Myocardial I/R was produced by occlusion of left anterior descending branch of coronary artery for 30 min followed by reperfusion for 120 min.Sham group only underwent thoracotomy without block of left anterior descending branch of coronary artery.Endoplasmic reticulum stress inhibitor 4-PBA 500 mg·kg -1·d -1 was given intragastrically for 3 consecutive days before the I/R model was developed in PBA group, while the equal volume of normal saline was given instead in Sham and IR groups.The blood samples from the iliac vein were collected at 120 min of reperfusion for determination of the plasma creatine kinase isoenzymes (CK-MB) and cardiac troponin I (cTnI) concentrations (by enzyme-linked immunosorbent assay). The rats were then sacrificed, and myocardial tissues were removed for detection of myocardial glucose-regulated protein 78 (GRP78) and microtubule-associated protein 1 light chain 3 Ⅱ (LC3 Ⅱ) and autophagy-related protein 5 (ATG5) expression (by Western blot). Result:Compared with Sham group, the concentrations of CK-MB and cTnI in plasma were significantly increased in IR and PBA groups, the expression of GRP78, ATG5 and LC3Ⅱ was up-regulated, and the pathological damage was aggravated in IR group ( P<0.05). Compared with IR group, the concentrations of CK-MB and cTnI in plasma were significantly decreased, the expression of GRP78, ATG5 and LC3Ⅱ was down-regulated ( P<0.05), and the pathological changes were significantly attenuated in PBA group. Conclusion:Endoplasmic reticulum stress is involved in the process of myocardial I/R injury, and the mechanism may be related to promotion of autophagy in rats.
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Objective To compare the efficacy of different concentrations of pyruvate-based peritoneal dialysis solution for peritoneal resuscitation in a rat model of hemorrhagic shock.Methods Forty SPF healthy male Sprague-Dawley rats,weighing 200-250 g,were assigned to 4 groups (n=10 each) using a random number table method:sham operation group (S group),routine Ⅳ resuscitation group (VR group),and intraperitoneal resuscitation with different concentrations of pyruvate-based peritoneal dialysis solution groups (PY1 group,PY2 group).The animals were anesthetized with pentobarbital sodium 400 mg/kg.Hemorrhagic shock was induced by withdrawing blood from the left femoral artery until mean arterial pressure (MAP) was reduced to 30-40 mmHg and maintained for 60 min,and the animals were then resuscitated by infusion of shed blood.In VR group,hemorrhagic shock was resuscitated by retransfusion of autologous blood and with normal saline 2 times the volume of blood loss at 1 h after hemorrhagic shock.Routine Ⅳ resuscitation was performed,and 40 and 80 mmol/L peritoneal dialysis solution 20 ml were intraperitoneally infused for 30 min at the same time in PY1 and PY2 groups,respectively.MAP was recorded before blood-letting (T0),at 5,30 and 60 min of shock (T1-3) and 5,30,60,90 and 120 min after the end of resuscitation (T4-8).Blood samples were collected at T8 for blood gas analysis,and pH value,partial pressure of oxygen (PaO2),partial pressure of carbon dioxide (PaCO2),base excess (BE),and bicarbonate ion concentration (HCO3-) were recorded.Results Compared with S group,MAP was significantly decreased at T1-8 in VR and PY1 groups and at T1-7 in PY2 group,and pH value,PaO2,BE and HCO3-were significantly decreased,and PaCO2 was increased in VR group (P＜0.05).Compared with VR group,MAP at T4-8,pH value,PaO2,BE and HCO3-were significantly increased,and PaCO2 was decreased in PY1 and PY2 groups (P＜0.05).Compared with PY1 group,MAP at T6-8 and pH value were significantly increased (P＜0.05),and no significant change was found in PaO2,PaCO2,BE or HCO3-in PY2 group (P＞0.05).Conclusion Peritoneal resuscitation with 80 mmol/L pyruvate-based peritoneal dialysis solution produces better efficacy than 40 mmol/L in a rat model of hemorrhagic shock.
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Objective To evaluate the relationship between the pathomechanism of neuropathic pain (NP)-inducced depression and autophagy in the cortex of the frontal lobe in rats.Methods Forty healthy male Sprague-Dawley rats in which IT catheters were successfully placed,aged 8-10 weeks,weighing 200-220 g,were divided into 4 groups (n =10 each) using a random number table method:sham operation group (group S),group NP,NP plus dimethyl sulfoxide group (group ND) and NP plus autophagy inducer rapamycin group (group NR).The neuropathic pain model was established by ligation of the left fifth spinal nerve of anesthetized rats in NP,ND and NR groups.Rapamycin 0.1 μgwas intrathecally injected via the intrathecal catheter immediately after ligation of the spinal nerve and every day after ligation once a day for 21 consecutive days in group NR.The equal volume of dimethyl sulfoxide was intrathecally injected instead of rapamycin in group ND.The mechanical paw withdrawal threshold (MWT) was measured before ligation and at 1,3,7,10,14 and 21 days after ligation.The forced swimming test was performed at 3 days before ligation and 14 and 21 days after ligation.The rats were sacrificed after the last measurement of the behaviour testing,and the prefrontal cortex was removed for determination of the expression of microtubule-associated protein light chain 3 Ⅰ (LC3 Ⅰ) and LC3 Ⅱ,Beclin-1 and p62 (by Western blot).The ratio of LC3 Ⅱ/LC3 Ⅰ was calculated.Results Compared with group S,the MWT was significantly decreased after ligation,the time of immobility was prolonged,the expression of LC3 Ⅰ was down-regulated,the expression of LC3 Ⅱ,Beclin-1 and p62 was up-regulated,and the LC3 Ⅱ/LC3 Ⅰ ratio was increased in NP and ND groups (P＜0.05).Compared with group NP,the MWT was significantly increased after ligation,the time of immobility was shortened,the expression of LC3 [and p62 was down-regulated,the expression of LC3 Ⅱ and Beclin-1 was up-regulated,and the LC3 Ⅱ/LC3 Ⅰ ratio was increased in group NR (P＜0.05).Conclusion Enhanced autophagy in the cortex of the frontal lobe is involved in the endogenous antidepressant mechanism in rats with NP.
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Objective To evaluate the role of M3 receptors in penehyclidine hydrochloride ( PHC)-induced reduction of lipopolysaccharide ( LPS)-induced injury to human pulmonary microvascular endotheli-al cells ( PMVECs) . Methods Human PMVECs transfected with M3 shRNA were seeded in 6-well plates (2 ml∕hole) or in culture flasks (4 ml∕flask) at the density of 1×105 cells∕ml and divided into 5 groups ( n=5 each) using a random number table method: control group ( group C) , LPS group, PHC plus LPS group ( group P+LPS) , LPS plus M3 shRNA transfection group ( group LPS+shRNA) , and PHC plus LPS plus M3 shRNA transfection group ( group P+LPS+shRNA) . Group C received no mediation, and LPS was added at the final concentration of 0. 1 μg∕ml in the other groups. PHC 2 μg∕ml was added at 1 h before adding LPS in P+LPS and P+LPS+shRNA groups. The cells were transfected with plasmid containing 2. 5 nmol∕L M3 receptor shRNA in LPS+shRNA group and P+LPS+shRNA group. Contents of filamentous actin ( F-actin) in endothelial cells were measured by flow cytometry at 1 h after adding LPS. The expression of myosin light chain kinase ( MLCK) and VE-cadherin protein was examined by immunofluorescence. The ex-pression of nuclear factor kappa B ( NF-κB) p65 and IκB was detected by Western blot. Contents of tumor necrosis factor-alpha ( TNF-α) and interleukin-6 ( IL-6) were determined by enzyme-linked immunosorbent assay. The M3 receptor mRNA transcription was detected by real-time polymerase chain reaction at 10, 30 and 60 min after adding LPS. Results Compared with group C, F-actin content was significantly de-creased, the expression of VE-cadherin and IκB was down-regulated, the contents of TNF-αand IL-6 were increased, and the expression of MLCK and NF-κB p65 was up-regulated in LPS and P+LPS groups ( P<0. 05) . Compared with group C, the expression of M3 receptor mRNA was significantly up-regulated in group LPS ( P<0. 05) , and no significant change was found in group P+LPS ( P>0. 05) . Compared with group LPS, F-actin content was significantly increased, the expression of VE-cadherin and IκB was up-reg-ulated, the contents of TNF-αand IL-6 were decreased, and the expression of MLCK, NF-κB p65 and M3 receptor mRNA was down-regulated in group P+LPS and group LPS+shRNA ( P<0. 05) . Compared with group P+LPS, F-actin content was significantly increased, the expression of VE-cadherin and IκB protein was up-regulated, TNF-α and IL-6 contents were decreased, and the expression of MLCK, NF-κB p65 and M3 receptor mRNA was down-regulated in group P+LPS+shRNA ( P<0. 05) . Conclusion PHC re-duces LPS-induced injury to human PMVECs through interfering with M3 receptors and inhibiting NF-κB-mediated inflammatory responses.
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Objective To evaluate the role of β-arrestin-1 in penehyclidine hydrochloride (PHC)-induced inhibition of lipopolysaccharide (LPS)-caused increase in pulmonary microvascular permeability in human pulmonary microvascular endothelial cells (PMVECs).Methods Human PMVECs were seeded in 6-well plates (2 ml/well) or in culture flasks (4 ml/flask) at the density of 1 × 105 cells/ml and divided into 5 groups (n=15 each) using a random number table:empty plasmid transfection group (group C),LPS plus empty plasmid transfection group (LPS group),PHC plus LPS plus empty plasmid transfection group (P+LPS group),LPS plus β-arrestin-1 short hairpin RNA (shRNA) transfection group (LPS+shRNA group) and PHC plus LPS plus β-arrestin-1 shRNA transfection group (P+LPS+shRNA group).In LPS and LPS+shRNA groups,the cells were transfected with empty plasmid 1.5 μg or with plasmid containing 15 nmol/L β-arrestin-1 shRNA,LPS with the final concentration of 0.1 μg/ml was added at 24 h of incubation,and the cells were then incubated for 1 h.In P+LPS and P+LPS+shRNA groups,the cells were transfected with empty plasmid 1.5 μg or with plasmid containing 15 nmol/L β-arrestin-1 shRNA,PHC with the final concentration of 2 μg/ml was added at 24 h of incubation,LPS with the final concentration of 0.1 μg/ml was added at 1 h of incubation,and the cells were then incubated for 1 h.The cell permeability was measured using Transwell chambers.The expression of heat shock protein (HSP27) was detected by immunofluorescence.The expression of β-arrestin-1,p38 mitogen-activated protein kinase (p38MAPK) and phosphorylated p38MAPK (p-p38MAPK) was detected by Western blot.The ratio of pp38MAPK/p38MAPK was calculated.Results Compared with group C,the cell permeability was significantly increased,the expression of HSP27 was up-regulated,p-p38MAPK/p38MAPK ratio was increased,and the expression of β-arrestin-1 was down-regulated in LPS,LPS + shRNA and P + LPS + shRNA groups (P＜0.05),and no significant change was found in the parameters mentioned above in group P+LPS (P＞ 0.05).Compared with group LPS,the cell permeability was significantly decreased,the expression of HSP27 was down-regulated,p-p38MAPK/p38MAPK ratio was decreased,and the expression of β-arrestin1 was up-regulated in group P +LPS,and p-p38MAPK/p38MAPK ratio was significantly increased (P＜0.05),and no significant change was found in the other parameters in group P+LPS+shRNA (P＞0.05).Compared with group P+LPS,the cell permeability was significantly increased,the expression of HSP27 was up-regulated,p-p38MAPK/p38MAPK ratio was increased,and the expression of β-arrestin-1 was down-regulated in group P+LPS+shRNA (P＜0.05).Conclusion The mechanism by which PHC inhibits LPS-induced increase in pulmonary microvascular permeability is totally related to β-arrestin-1 in human PMVECs.
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Objective To evaluate the effect of peritoneal resuscitation (PR) with pyruvate-based peritoneal dialysis solution (PDS) on kidney injury in a rat model of hemorrhagic shock.Methods Fifty healthy adult male Sprague-Dawley rats,weighing 200-250 g,aged 8 weeks,were divided into 5 groups (n=10 each) using a random number table:sham operation group (group SH),conventional Ⅳ resuscitation group (group VR),PR with normal saline group (group NS),PR with lactate-based PDS group (group LA) and PR with pyruvate-based PDS group (group PY).Hemorrhagic shock was induced by withdrawing blood from the left femoral artery at a rate of 0.6 ml/min about 10 min until mean arterial pressure was reduced to 30-40 mmHg which was maintained for 1 h.In group VR,the animals were resuscitated with infusion of the blood withdrawn and normal saline (the volume was 2 times volume of blood loss) at 1 h after hemorrhagic shock.In NS,LA and PY groups,conventional Ⅳ resuscitation was performed,and the animals were simultaneously resuscitated with normal saline,lactate-based PDS,and pyruvatebased PDS 20 ml infused intraperitoneally over 30 min,respectively.The animals were sacrificed at 180 min after resuscitation,and kidneys were removed for examination of the pathological changes (with a light microscope) and for measurement of the content of malondialdehyde (MDA) and activities of myeloperoxidase (MPO) and superoxide dismutase (SOD) in renal tissues.The damage to renal tubules was assessed and scored.Results Compared with group SH,the renal tubular damage scores,MDA content and MPO activity were significantly increased,and the activity of SOD was decreased in the other four groups (P＜0.05).Compared with group VR,the renal tubular damage scores,MDA content and MPO activity were significantly decreased,and the activity of SOD was increased in NS,LA and PY groups (P＜0.05).Compared with group NS or group LA,the renal tubular damage scores,MDA content and MPO activity were significantly decreased,and the activity of SOD was increased in group PY (P＜0.05).The pathological changes of renal tissues were significantly attenuated in group PY when compared with VR,NS and LA groups.Conclusion PR with pyruvate-based PDS can reduce kidney injury in a rat model of hemorrhagic shock.
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Objective To evaluate the relationship between inflammatory responses and autophagy in lung tissues after scald and nucleotide-binding oligomerization domain-containing protein 2 (NOD2) signaling pathway in septic rats.Methods Twenty SPF healthy male Sprague-Dawley rats,weighing 200-250 g,were divided into control group (group C,n=10) and sepsis after scald group (group SS,n=10) using a random number table.The rats were subjected to a third-degree scald burn covering 20％ of total body surface area (body surface was shaved and then exposed to 99-100 ℃ water for 12 s),and 24 h later muramyldipeptide 5 mg/kg was intravenously injected to induce sepsis.The rats were only exposed to 20 ℃ water,and 24 h later normal saline 1 ml was given instead in group C.At 6 h after muramyldipeptide injection in group SS and at 6 h after normal saline injection in group C,arterial blood samples were collected for determination of serum tumor necrosis factor-r and interleukin-6 concentrations by enzyme-linked immunosorbent assay.Then rats were sacrificed and lungs were removed tor measurement of activity of myeloperoxidase,NOD2 mRNA expression (using real-time polymerase chain reaction) and expression of receptor interacting protein 2,nuclear factor kappa Bp65 and microtubule-associated protein 1 light chain 3 Ⅰ (LC3 Ⅰ) and LC3 Ⅱ in lung tissues (by Western blot).The LC3 Ⅱ / Ⅰ ratio was calculated.Results Compared with group C,the expression of NOD2 mRNA,receptor interacting protein 2 and nuclear factor kappa Bp65 was significantly up-regulated,and the LC3 Ⅱ / Ⅰ ratio and serum tumor necrosis factor-α and interleukin-6 concentrations were increased in group SS (P＜0.05).Conclusion The mechanism underlying enhanced inflammatory responses and autophagy in lung tissues during sepsis after scald may be related to activation of NOD2 signaling pathway in rats.
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Objective To evaluate the efficacy of preoperative transversus abdominis plane (TAP) block with different volumes of ropivacaine for improving postoperative analgesia in patients undergoing laparoscopic radical resection of ovarian cancer.Methods Sixty American Society of Anesthesiologists physical status Ⅰ or Ⅱ patients,aged 30-60 yr,with body mass index of 18-24 kg/m2,scheduled for elective laparoscopic radical resection of ovarian cancer under general anesthesia,were divided into 3 groups (n =20 each) using a random number table:0.375％ ropivacaine 20 ml group (group R1),0.375％ ropivacaine 12 ml group (group R2) and control group (group C).In R1 and R2 groups,ultrasound-guided bilateral TAP block was performed before induction of anesthesia,and 0.375％ ropivacaine 20 and 12 ml were injected,respectively.Both groups received patient-controlled intravenous analgesia (PCIA) with sufentanil after operation,and the PCIA pump was set up with a 0.5 ml bolus dose,a 15 min lockout interval and background infusion at a rate of 2 ml/h after a loading dose of 2 ml to maintain the visual analogue scale score ≤ 3.When the visual analogue scale score ＞3,tramadol 100 mg was intravenously injected as rescue analgesic.The consumption of sufentanil during PCIA,effective pressing times of PCIA,requirement for rescue analgesic and occurrence of adverse reactions were recorded within 24 h after operation.At 10 min before induction of anesthesia and 4,8,12 and 24 h after operation,venous blood samples were collected for measurement of the plasma concentrations of interleukin-6 (IL-6) and IL-10 by enzyme-linked immunosorbent assay.Results Compared with group C,the consumption of sufentanil,effective pressing times of PCIA,requirement for rescue analgesic and incidence of nausea and vomiting and pruritus were significantly decreased,and the concentration of plasma IL-6 was decreased and the concentration of IL-10 in plasma was increased at each time point after operation in R1 and R2 groups (P＜0.05).The consumption of sufentanil,effective pressing times of PCIA,requirement for rescue analgesic and incidence of nausea and vomiting and pruritus were significantly lower,and the concentration of plasma IL-6 was lower and the concentration of IL-10 in plasma was higher at each time point after operation in group R1 than in group R2 (P＜0.05).Hematoma and infection at the puncture site were not found in R1 and R2 groups.Conclusion Preoperative TAP block can enhance the postoperative analgesic efficacy,reduce the occurrence of adverse reactions,and 0.375％ ropivacaine 20 ml provides better efficacy in patients undergoing laparoscopic radical resection of ovarian cancer.
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Objective To investigate the effects of heme oxygenase-1 (HO-1) transduced by cell penetrating peptide PEP-1 on renal ischemia/reperfusion (I/R) injury in rats.Methods Eighteen male Sprague-Dawley rats,aged 7-9 weeks,weighing 210-260 g,were randomly divided into 3 groups (n =6 each):sham operation group (group S),renal I/R injury group (group I/R) and fusion protein PEP-1/HO-I + I/R group (group HO).I/R injury was produced by occluding bilateral renal arteries for 45 min followed by reperfusion for 6 h.The fusion protein PEP-1/HO-1 was injected via the left iliac vein 30 min prior to ischemia in group HO.Bilateral renal arteries were only exposed but not occluded in group C.Blood samples were collected from the right common carotid artery at 6 h of reperfusion for determination of serum blood urea nitrogen (BUN) and creatinine (Cr) concentrations.The malondialdehyde (MDA) content,superoxide dismutase (SOD) activity and HO-1 expression in renal tissues were measured.Results Compared with group S,the levels of MDA,serum BUN and Cr were significantly increased,the SOD activity was decreased,and HO-1 expression was up-regulated in groups I/R and HO (P ＜0.05).Compared with group I/R,the levels of MDA,serum BUN and Cr were significantly decreased,the SOD activity was increased,and HO-1 expression was up-regulated in group HO (P ＜ 0.05).Conclusion HO-1 protein can be successfully transduced into renal tissues by PEP-1 and transduced HO-1 protein reduces renal I/R injury by inhibiting lipid peroxidation response.
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Objective To evaluate the effects of heme oxygenase-1 (HO-1) mediated by cell penetrating peptide PEP-1 on liverinjury induced by intestinal ischemia/reperfusion (I/R) in rats.Methods Twenty-four male Sprague-Dawley rats,aged 7-9 weeks,weighing 210-260 g,were randomly divided into 3 groups (n =8 each):sham operation group (group S),intestinal I/R group (group I/R) and PEP-1/HO-1 group (group HO).To establish a model of intestinal I/R,intestines were exteriorized and the superior mesenteric artery was exposed and occluded for 45 min ischemia,and then the clamp was removed for 120 min reperfusion.The PEP-1/HO-1 fusion protein 0.5 mg was injectedvia ihe left iliac vein 30 min prior to ischemia in group HO.The superior mesenteric artery was only exposed but not occluded in group S.At the end of reperfusion,blood samples were collected from the right common carotid artery for measurement of serum aspartate aminotransferase (AST),alanine aminotransferase (ALT) activities.The rats were then sacrificed and livers were removed for microscopic examination and for determination of malondialdehyde (MDA) content and superoxide dismutase (SOD) activity in livertissues.Results Compared with group S,serum AST and ALT activities and MDA content in liver tissues were significantly increased,while SOD activity in liver tissues was decreased in groups I/R and HO (P ＜ 0.05).Compared with group I/R,serum AST and ALT activities and MDA content in liver tissues were significantly decreased,while SOD activity in liver tissues was increased in group HO (P ＜0.05).Liver injury induced by intestinal I/R was significantly attenuated in group HO compared with group I/R (P ＜ 0.05).Conciusioon HO-1 protein mediated by cell penetrating peptide PEP-1 can attenuate liver injury induced by intestinalI/R in rats.
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Objective To investigate the effect of PEP-1-heme oxygenase-1 (PEP-1-HO-1) fusion protein transduction on hypoxia-reoxygenation (H/R) injury in rat H9c2 cells. Methods After construction of the prokaryotic expression plasmid pET15b-PEP-1-hHO-1 containing the human heme oxygenase-1 gene, it was then transformed to make PEP-1-HO-1 fusion protein express. The H9c2 cells were cultured in high-glucose Dulbecco's modified Eagle's medium (DMEM) supplemented with 15% fetal bovine serum and randomly divided into 4 groups (n = 4 each): control group (group C), H/R group, low-concentration fusion protein group (group L-HO), and high-concentration fusion protein group (group H-HO). The cells were exposed to 22 h of hypoxia followed by 8 h of reoxygenation. PEP-1-HO-1 fusion protein was added to the culture medium with a final concentration of 1.0 μ mol/L (group L-HO) or 2.0 μmol/L (group H-HO) before hypoxia. The cells and supernatant of the culture medium were collected after reoxygenation to determine the activity of lactate dehydrogenase (LDH) in the supernatant and the content of malondialdehyde (MDA) and activity of superoxide dismutase (SOD) in the cells. Results The SOD activity was significantly lower, while the MDA content and LDH activity were significantly higher in group H/R, L-HO and H-HO than in group C (P ＜0.05). The SOD activity was significantly higher, while MDA content and LDH activity were significantly lower in group L-HO and H-HO than in group H/R, and in group H-HO than in group L-HO ( P ＜ 0.05). Conclusion PEP-1-HO-1 fusion protein transdution can protect H9c2 cells against H/R injury in rats.
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Objective To investigate the protective effects of heme oxygenase-1 (HO-1) mediated by cell penetrating peptide PEP-1 on myocardium against ischemia/reperfusion (IR) injury in isolated rat hearts. Methods Healthy male SD rats weighing 220-280 g were anesthetized with intraperitoneal pentobarbital. Their hearts were excised and perfused in a Langendorff apparatus with K-H solution saturated with 95%O2-5% CO2 at 37 ℃. Eighteen isolated rat hearts were randomly divided into 3 groups ( n = 6 each): Ⅰ group sham operation (group S);Ⅱ group IR and Ⅲ group PEP-1/HO-1 + IR (group HO-1). The isolated rat hearts were perfused with an oxygena-ted (95% O2-5% CO2 ) K-H solution at 37 ℃ in a Langendorff apparatus and were subjected to 40 min of global ischemia followed by 50 min of reperfusion after 30 min of stabilization. In group Ⅲ (group HO- 1 ) the isolated hearts were perfused with 50 μmol/L PEP-1/HO-1 for 15 min before ischemia. After 50 min of reperfusion, HO-1expression, MDA content and SOD activity in myocardial tissues were determined. The activities of creatine kinase (CK) and lactic dehydrogenase (LDH) in coronary effluent fluid were measured. Results The HO- 1 expression was significanfly higher in HO-1 group than in group IR. IR induced significant increase in MDA content and decrease in SOD activity in myocardium and CK and LDH activities in coronary effluent in group Ⅱ compared with group S. PEP-1/HO-1 significantly attenuated IR-induced changes. Conciusion HO-1 mediated by PEP-1 has protective effects on myocardium ngainst IR injury in rats.