1.Mechanisms of tumor necrosis factor-related apoptosis inducing ligandcombined with Triptolide in inducing the apoptosis of pancreatic cancer cells
Yan JIANG ; Wei LIU ; Zhiyu CHEN
Chinese Journal of Digestive Surgery 2015;14(4):321-328
Objective To investigate the mechanisms of tumor necrosis factor-related apoptosis inducing ligand (TRAIL) combined with Triptolide in inducing the apoptosis of pancreatic cancer cells.Methods (1) The pancreatic cancer cells (MiaPaca-2 cells) were divided into 4 groups:blank control group (no drugs were added),TRAIL + Triptolide-group (only TRAIL was added),TRAIL-Triptolide + group (only Triptolide was added) and TRAIL+ Triptolide+ group (TRAIL and Triptolide were added).The vitality of cells in all the 4 groups was assessed by CCK-8.The expressions of poly ADP-ribose polymerase (PARP),cysteinyl aspartate specific proteinase-3 (Caspase-3) and Caspase-8 were detected by Western blot.The vitality of cells was detected by CCK-8 and the vitality of Caspase-8 was detected by Caspase-Glo assays after adding Z-IETD-FMK,a specific inhibitor of Caspase-8.The expressions of myeloid cell leukemia-1 (Mcl-1),Bcl-xL and Bcl-2 were detected by Western blot.(2) The MiaPaca-2 cells were divided into 8 groups:①TRAIL-Mcl-1 siRNA-group (no TRAIL was added and Mcl-1 siRNA cells were not transfected),TRAIL+ Mcl-1 siRNA-group (TRAIL was added and Mcl-1 siRNA cells were not transfected),TRAIL-Mcl-1 siRNA + group (TRAIL was not added and Mcl-1 siRNA cells were transfected)and TRAIL+ Mcl-1 siRNA+ group (TRAIL was added and Mcl-1 siRNA cells were transfected).②TRAIL-Bcl-xL siRNA-group (TRAIL was not added and Bcl-xL siRNA was not transfected),TRAIL+ Bcl-xL siRNA-group (TRAIL was added and Bcl-xL siRNA was not transfected),TRAIL-Bcl-xL siRNA + group (TRAIL was not added and Bcl-xL siRNA was transfected) and TRAIL+ Bcl-xL siRNA+ group (TRAIL was added and Bcl-xL siRNA was transfected).The vitality of the cells in all the groups was detected by CCK-8.The expressions of Caspase-3 and Caspase-8 protein were detected by Western blot.The measurement data with normal distribution were presented as (x) ± s.The comparison among groups was done by ANOVA,and the pairwise comparison was done by LSD-t test.Results (1) The vitalities of MiaPaca-2 cells in the blank control group,TRAIL + Triptolide-group,TRAIL-Triptolide + group and TRAIL + Triptolide + group were 100.0% ± 1.1%,81.2% ± 2.3%,78.6% ± 3.6%and 40.1% ± 2.5 %,and the relative expressions of PARP protein were 0.510 ± 0.028,0.720 ±0.072,1.250 ±0.023 and 2.560 ± 0.220,the relative expressions of Caspase-3 were 0.080 ± 0.004,0.080 ± 0.003,0.110 ±0.005 and 2.720 ± 0.003,and the relative expressions of Caspase-8 were 0.070 ± 0.003,0.080 ± 0.005,0.120 ±0.003 and 0.990 ± 0.006,with significant differences among the 4 groups (F =203.607,1 457.785,332 421.900,35 437.218,P < 0.05).The vitality of M iaPaca-2 cells in the TRAIL + Triptolide + group was significantly different from those in the blank control group,the TRAIL + Triptolide-group and the TRAIL-Triptolide + group (t =34.583,355.936,36.271,P < 0.05).The relative expression of PARP protein of MiaPaca-2 cells in the TRAIL+ Triptolide + group was significantly different from those in the blank control group,TRAIL+ Triptolidegroup and TRAIL-Triptolide + group (t =591.784,63.739,2 268.987,P < 0.05).The relative expression of Caspase-3 protein of the MiaPaca-2 cells in the TRAIL + Triptolide + group was significantly different from those in the blank control group,the TRAIL + Triptolide-group and theTRAIL-Triptolide + group (t =3 266.153,9 145.228,1 738.713,P <0.05).The relative expression of Caspase-8 protein of the MiaPaca-2 cells in the TRAIL+ Triptolide +group was significantly different from those in the blank control group,the TRAIL+ Triptolide-group and the TRAIL-Triptolide + group (t =663.953,l 432.878,327.584,P < 0.05).The vitality of caspase-8 in the TRAIL+ Triptolide+ group was 711.0% ± 5.1% before adding Z-IETD-FMK,and then the vitality of MiaPaca-2 cells and caspase-8 changed to 70.0% ± 4.8% and 73.0% ± 2.4%,with significant differences (t =17.956,55.027,P < 0.05).The relative expressions of Mcl-1 protein in the blank control group,the TRAIL + Triptolidegroup,the TRAIL Triptolide + group and the TRAIL + Triptolide + group were 1.68 ± 0.22,2.08 ± 0.11,0.73 ±0.15 and 0.58 ± 0.18,the relative expressions of Bcl-xL protein were 0.65 ± 0.03,0.47 ± 0.03,0.32 ± 0.03and 0.26 ±0.05,the relative expressions of Bcl-2 protein were 0.65 ± 0.03,0.67 ± 0.03,0.62 ± 0.05 and 0.67 ± 0.03,with significant difference among the 4 groups (F =55.178,88.683,3.411,P < 0.05).The relative expressions of Mcl-1 protein of the MiaPaca-2 cells in the TRAIL-Triptolide + group and the TRAIL+ Triptolide +group were significantly different from those of the blank control group (t =23.506,47.631,P < 0.05) and the TRAIL + Triptolide-group (t =58.457,37.115,P < 0.05).The relative expressions of Bcl-xL protein of the MiaPaca-2 cells in the TRAIL-Triptolide + group and the TRAIL + Triptolide + group were significantly different from those of the blank control group (t =38.105,42.219,P < 0.05) and the TRAIL + Triptolide-group (t =32.476,15.814,P < 0.05).The relative expressions of Bcl-2 protein in the TRAIL-Triptolide + group and the TRAIL+ Triptolide + group were not significantly different from those of the blank control group (t =4.724,1.732,P > 0.05) and the TRAIL + Triptolide-group (t =3.464,0.000,P > 0.05).(2) The vitalities of MiaPaca-2 cells of the TRAIL-Mcl-1 siRNA-group,TRAIL + Mcl-1 siRNA-group,the TRAIL-Mcl-1 siRNA + group and the TRAIL + Mcl-1 siRNA + group were 100.0% ± 2.2%,79.3% ± 1.8%,71.2% ± 3.2% and 37.3% ± 5.4%,the relative expressions of Caspase-8 protein were 0.100 ± 0.003,0.100 ± 0.005,0.100 ± 0.003 and 0.350 ±0.005,and the relative expressions of Caspase-3 protein were 0.020 ± 0.003,0.060 ± 0.003,0.020 ± 0.003 and 0.590 ±0.004,with significant differences among the 4 groups (F =136.681,2 717.391,44 471.429,P <0.05).The vitality of MiaPaca-2 cells of the TRAIL + Mcl-1 siRNA + group was significantly different from those in the TRAIL-Mcl-1 siRNA-group,the TRAIL + Mcl-1 siRNA-group and the TRAIL-Mcl-1 siRNA + group (t =33.937,20.207,26.689,P < 0.05).The relative expression of Caspase-8 protein of the TRAIL + Mcl-1 siRNA +group was significantly different from those in the TRAIL-Mcl-1 siRNA-group,the TRAIL + Mcl-1 siRNA-group and the TRAIL-Mcl-1 siRNA + group (t =216.506,433.013,144.338,P < 0.05).The relative expression of Caspase-3 protein of the TRAIL + Mcl-1 siRNA + group was significantly different from those in the TRAIL-Mcl-1 siRNA-group,the TRAIL + Mcl-1 siRNA-group and the TRAIL-Mcl-1 siRNA + group (t =329.09,458.993,987.269,P <0.05).The vitalities of MiaPaca-2 cells of the TRAIL-Bcl-xL siRNA-group,the TRAIL+ Bcl-xL siRNA-group,the TRAIL-Bcl-xL siRNA + group and the TRAIL+ Bcl-xL siRNA + group were 100.0% ± 2.3%,87.2% ± 4.1%,74.1 ± 3.7% and 56.3% ± 5.4%,and the relative expressions of Caspase-3 protein were 0.060 ±0.004,0.070 ± 0.003,0.060 ± 0.004 and 0.390 ± 0.003,with significant differences among the 4 groups (F =70.074,4 643.478,P < 0.05).The vitality of MiaPaca-2 cells of the TRAIL + Bcl-xL siRNA + group was significantly different from those in the TRAIL-Bcl-xL siRNA-group,the TRAIL+ Bcl-xL siRNA-group and the TRAIL-Bcl-xL siRNA + group (t =24.416,41.170,18.136,P < 0.05).The relative expression of Caspase-3 protein of the TRAIL + Bcl-xL siRNA + group was significantly different from those in the TRAIL-Mcl-1 siRNA-group,the TRAIL + Mcl-1 siRNA-group and the TRAIL-Mcl-1 siRNA + group (t =285.788,554.256,190.526,P < 0.05).Conclusion Triptolide could induce the apoptosis of MiaPaca-2 cells by inhibiting the expressions of Mcl-1 and Bcl-xL,sensitizing TRAIL and activating Caspase-8 and Caspase-3.
2.Diagnosis and treatment of the sphenoid sinus malignant tumor
Xing YE ; Zhiyu YAN ; Guangliang GUO ;
Chinese Archives of Otolaryngology-Head and Neck Surgery 2006;0(09):-
OBJECTIVE To investigate the clinical characteristics,nasal endoscope and imaging findings, misdiagnosis and treatment results of sphenoid sinus malignant tumor.METHODS The clinical data of 9 cases with sphenoid sinus malignant tumor were summarized and analyzed.Headache was found in 8 patients, ophthalmic symptoms in 3 patients,nasal bleeding and obstruction in 3 patients,and cranial nerve palsy in 2 patients.They were often misdiagnosed as sphenoid sinusitis and nasopharyngeal carcinoma.RESULTS Only 1 patient with papillary carcinoma was cured for 6 years.One patient with neuroendocrine carcinoma was alive for 3 years after treatment.Four patients died at 2 to 3 years.Two patients were alive at 1 year after operation. One patient was lost to follow up.CONCLUSION Sphenoid sinus tumor had no characteristic symptoms in early stage.It is easy to misdiagnose and delay diagnosis. Patients with headache,visual symptoms and nasal bleeding should take nasal endoscopy,CT scan and MRI examination at early stage.
3.Insulin-like growth factor 1 promotes in vitro proliferation of chondrocytes in traumatic arthritis
Guang ZHAO ; Jifeng JING ; Zhiyu ZHANG ; Jiajun ZHU ; Yan CUI
Chinese Journal of Tissue Engineering Research 2014;(2):183-186
BACKGROUND:The early damaged chondrocytes are susceptible to de-differentiate and exert unstable phenotype during the in vitro culture, thus needing some growth factors.
OBJECTIVE:To observe the promotion effect of insulin-like growth factor 1 on the in vitro proliferation of chondrocytes in adult rabbits with traumatic arthritis.
METHODS:Traumatic arthritis models of adult rabbits were established by using the modified Hulth method. After the models were successful y established, the distal femur and proximal tibia were harvested under sterile conditions, the chondrocytes were cultured. The cultured cells were divided into two groups:control group was cultured with Dulbecco’s modified Eagle’s medium containing 10%fetal bovine serum, while experimental group was cultured with Dulbecco's modified Eagle’s medium containing 100μg/L insulin-like growth factor 1. The effect of insulin-like growth factor 1 on the proliferation of chondrocytes in adult rabbits with traumatic arthritis was determined through the cytomorphology, cellcounting, and cellactivity.
RESULTS AND CONCLUSION:The chondrocytes in adult rabbits with traumatic arthritis were successful y cultured, the majority of cells were mini-cells, presenting smal fusiform, round or polygonal shape. Hematoxylin-eosin staining showed that the number of cells in experimental group was higher than that in control group. MTT assay found that the absorbance of cells in experimental group was greater than that in control group (P<0.01). Our findings indicate that, insulin-like growth factor 1 can promote the in vitro proliferation of chondrocytes in adult rabbits with traumatic arthritis.
4.Doppler ultrasound screening for deep vein thrombosis in patients with lower limb fracture
Youqing YAN ; Hua REN ; Kun FENG ; Chaohui DU ; Zhiyu WEI
Chinese Journal of General Practitioners 2011;10(9):673-674
One hundred and sixteen patients with lower limb fracture were screened by Doppler ultrasound for deep vein thrombosis(DVT) of bilateral lower extremities within the first 72 h, d7 and d21 after fracture. Results showed that DVT was detected in 31 (26. 7% ) out of 116 cases within 72 h; at d7 and d21 DVT was detected in 3 and 1 patient respectively with a cumulated DVT rate of 30. 2% in 3 weeks.Serial Doppler ultrasonography is of value in screening for DVT of the lower extremities in patients with lower limb fracture at early stage.
5.Three-dimensional printing technology-aided total knee arthroplasty for osteoarthritis with genu varum deformity
Zhenguo SUN ; Jiajun ZHU ; Yan CUI ; Shenghui NI ; Zhiyu ZHANG
Chinese Journal of Tissue Engineering Research 2017;21(15):2395-2399
BACKGROUND: The complicated localization of intramedullary nails and osteotomy more dependent on surgeons' experience limit the application of conventional total knee arthroplasty (TKA). The occurrence of three-dimensional (3D) printing technology can achieve precise localization and osteotomy in TKA.OBJECTIVE: To explore the effectiveness of 3D printing technology-aided TKA versus conventional TKA for genu varum.METHODS: Thirty-four patients with genu varum undergoing primary unilateral TKA were recruited and were then divided into two groups (n=17 per group) in accordance with the random number table. One group was treated with TKA with 3D printing guild plate (3D printing group), while the other group received the conventional TKA (conventional group).The intraoperative and postoperative blood loss, operation time, as well as the Hospital for Special Surgery score, range of motion, and lower limb mechanical alignment at 2 weeks postoperatively were compared between two groups.RESULTS AND CONCLUSION: (1) The range of motion of knee in the 3D printing group was larger than that in the conventional group, but had no significant difference at 2 weeks postoperatively (P=0.744). (2) There was no significant difference in the Hospital for Special Surgery scores between two groups at 2 weeks postoperatively (P= 0.532). (3) The postoperative lower limb mechanical alignment showed no significant difference between two groups (t=0.218, P=0.632).(4) The operation time in the 3D printing group was significantly shorter than that in the conventional group (P=0.000). (5) The blood loss in the 3D printing group was significantly less than that in the conventional group (P=0.000). (6) Our findings indicate that 3D printing technology-aided TKA exhibits similar results to the conventional TKA in the Hospital for Special Surgery scores, range of motion, and lower limb mechanical alignment, but it shortens the operation time,reduces the blood loss, and achieves precise osteotomy, which is available for the elderly with poor basic condition, and weak tolerance of surgery.
6.Three-dimensional total endoscopic thyroidectomy for thyroid carcinoma: a series of 32 cases.
Yong WANG ; Qunzi ZHAO ; Haichao YAN ; Qiuping XIE ; Zhiyu LI ; Ping WANG ; Shaoming XU
Chinese Journal of Surgery 2015;53(3):176-178
OBJECTIVETo summarize the experiences of applying three-dimensional (3D) technique in scarless endoscopic thyroidectomy (SET) via anterior chest approach.
METHODSMedical records of patients who undenvent SET using 3D technique from December 2013 to May 2014 were retrospectively reviewed. A total of 32 patients who had a preoperative ultrasound-guided fine-needle aspiration cytology diagnosis of unilateral papillary thyroid carcinoma and underwent lobectomy associated with central lymph node dissection were included in this study. All patients were female with a mean age of (37 ± 10) years at diagnosis. In addition, 45 female patients who underwent traditional endoscopic thyroidectomy at the same period were randomly selected as control.
RESULTSAll surgical procedures were successfully finished. The mean surgical time in 3D group was (91. 7 ± 11. 4) minutes, and mean hospitalization time was (3. 2 ± 0. 5) days. Contemporary hoarseness was observed in one patient, and no bleeding, infection, hypocalcemia and other postsurgical complications were observed. Compared to the traditional endoscopic surgery group, 3 D group had significantly shorter surgical time of lobectomy ((23. 2 ± 5. 1) minutes vs. (28. 0 ± 5. 0) minutes, t = 4. 156, P = 0. 000). Negative results were seen in the time taking of creating surgical space ((14. 6 ± 3. 3) minutes vs. (15. 6 ± 2. 5) minutes), central lymph node dissection ((25. 1 ± 5. 4) minutes vs. (24. 4 ± 6. 3) minutes) and total surgical time ((91.7 ± 11. 4) minutes vs. (96. 1 ± 13. 0) minutes).
CONCLUSIONApplication of 3D technique in endoscopic surgery can offer 3D vision of the surgical field, thus significantly shorten lobectomy time and more easily to achieve fine dissection and functional protection of recurrent laryngeal nerves, parathyroids and other vital anatomic structures.
Adult ; Biopsy, Fine-Needle ; Carcinoma ; diagnosis ; surgery ; Carcinoma, Papillary ; Endoscopy ; methods ; Female ; Humans ; Middle Aged ; Minimally Invasive Surgical Procedures ; methods ; Operative Time ; Retrospective Studies ; Thyroid Neoplasms ; diagnosis ; surgery ; Thyroidectomy ; methods
7.The impact of polyclonal neural cell adhesion molecule antibody on the potency of botulinum toxin
Yan GUO ; Lingjing JIN ; Wuchao LIU ; Yuguo ZHENG ; Qiang GUAN ; Lizhen PAN ; Zhiyu NIE
Chinese Journal of Physical Medicine and Rehabilitation 2013;35(11):833-838
Objective To investigate the impact of polyclonal neural cell adhesion molecule antibody (P-NCAM-Ab) on the potency of botulinum toxin A (BTX-A).Methods Ninety male Sprague-Dawley rats were randomly divided into 3 equal groups:a normal control group,a BTX-A group and a P-NCAM-Ab group.The rats in the normal control group were injected with 100 μl of saline solution in their right gastrocnemius,while those in the BTX-A and P-NCAM-Ab groups were injected with 100 μl of BTX-A (0.5 U).In addition,the rats in the P-NCAM-Ab group were also injected with 100 μl of P-NCAM-Ab (the dosage was 20 U) at the same site on the 3rd day after the BTX-A injection.The rats' gastrocnemius muscle strength was evaluated with a self-made system for evaluating neuromuscular function before and after the toxin injection,on the 3rd day,as well as 1,2,4,6,8,10 and 12 weeks after the BTX-A injection.Any wet weight changes in the muscles were observed,and immunochemistry methods were employed to observe any structural changes in the motor endplates and nerve fibers at the different time points.Results After the saline injection,the average gastrocnemius muscle strength of the control group increased with time,while strength in the BTX-A and P-NCAM-Ab groups demonstrated a decrease in strength followed by a gradual increase.The average gastrocnemius muscle strength of the rats in the BTX-A and P-NCAM-Ab groups was significantly lower than that of the control group at all time points.Compared with the BTX-A group,the muscle strength of the P-NCAM-Ab group rats decreased further.Strength recovery in the BTX-A and P-NCAM-Ab groups was significantly slower than in the control group.The wet weight percentage in the BTX-A and P-NCAM-Ab groups at first decreased and then recovered with time.After the BTX-A injection,the average wet weight percentage of the P-NCAM-Ab group rats was significantly lower than that of the BTX-A group after 3 days,and 1,2 and 4 weeks.Karnovsky-Roots AchE staining showed that the motor endplates' color in the BTX-A and P-NCAM-Ab groups deepened gradually,though the color of the P-NCAM-Ab group was lighter than that of the BTX-A group at each time point.The mean optical density of the motor endplates' positive reaction area increased with time in both groups,but the P-NCAM-Ab group was lower than that of the BTX-A group at 1,2,4,8 and 12 weeks.Counting the nerve fibers dyed by gold chloride showed similar trends with both experimental groups significantly different from the control group.Conclusion P-NCAM-Ab can increase the potency of BTX-A and prolong its action.
8.Experimental research on safety of myocardial contrast echocardiography
Li SU ; Lixue YIN ; Zhigang WANG ; Wenhua LI ; Bin LONG ; Zhiyu GUO ; Jie SHEN ; Yan LI
Chinese Journal of Ultrasonography 2012;21(6):514-520
ObjectiveTo evaluate the myocardium damage of myocardial contrast echocardiography (MCE) and the impact on regional left ventricular mechanics by imaging and pathology techniques.Methods Eleven open-chest animal models of Beagle were employed to collect the short-axis views of mitral annular,papillary muscle and apical level of three complete cardiac cycles using gray-scale imaging at the baseline and blank irradiation 5 min later(transmitting frequency 1.7/3.4 M Hz,mechanical index 1.0).After that,5 ml of SonoVue was gotten a shot by intravenous bolus injection,the heart was exposed by ultrasonic wave for 5 min continuously,and then the same images collected were at the point-in-time irradiation immediately,20 min,40 min and 60 min later.The short-axis circumferential strain and strain rate,radial strain and strain rate were measured and calculated by EchoPAC multi-parameter workstation,meanwhile including conventional of cardiac function.All the dogs were killed after the experiments and the myocardium was harvested for HE staining and observed with transmission electron microscope for the tissue microstructure.Results①Conventional parameters of cardiac function:there was no significant difference before and after MCE in the heart rate,blood pressure,ejection fraction,left ventricular end-systolic volume and end-diastolic volume,stroke volume,cardiac output,mitral flow spectrum prior to the E/A,tissue Doppler mitral annular e/a and E/e ( P >0.05).During the whole process of experiment,the dogs’ vital signs were stable.②Compared the segmental circumferential strain and strain rate,radial strain and strain rate between baseline and each treatment groups,these parameters had a trend of increase in most segments,but the difference was not statistically significant in most segments (P >0.05).③HE staining at the light microscope demonstrated a small amount of myocardial cell infiltration of inflammatory cells near the outer membrane (21.2%),and very few part of the muscle fibers dissolved and fractured (6.1%).④The section of transmission electron microscope showed all the structures were normal except that a small amount of endothelial cells were mild swelling,some red blood cells were leaked,some myofilaments were regional dissolved,the relevance ratio were 28.6 %,42.9 % and 21.4 % respectively,and the abnormal area was less than 10% of the entire field of vision.ConclusionsMCE has no significant impact for the global function of heart and the regional mechanical state,and furthermore there is no serious pathological damage on the myocardium.
9.Ischemic postconditioning attenuates myocardial cell injury by ischemia-reperfusion injury in rabbits
Yan HE ; Zhiyu ZENG ; Jinyi LI ; Guoqiang ZHONG ; Wei LI ; Weike LI ; Honghong KE
Basic & Clinical Medicine 2010;30(2):133-138
Objective To investigate the effects of ischemic postconditioning on apoptosis, structural and functional changes of mitochondria induced by myocardial isehemia/reperfusion (I/R) injury of rabbits and potential mechanism. Methods Eighty healthy rabbits were divided randomly into five groups: sham operation group ( Group Sham) , ischemic reperfusion group (Group IR) , ischemic preconditioning group (Group IP) , ischemic postconditioning group (Group PC) and 5-HD plus ischemic postconditioning group (Group PC +5-HD). All rabbits in the five groups were killed 4 h after reperfusion. The hearts were quickly collected for microscopy by TUNEL. We observed ultrastructural changes of myocardium under electron microscope and examined mitochondrial membrane potential and Ca~(2+) concentration, MDA content and SOD activity of myocardial mitochondria. Results Compared with group IR, the damage of mitoehondrial ultrastrueture was milder, the apoptosis rate decreased and Ca concentration and MDA content were much lower in group IP and group PC ( P < 0. 05 ). Mitochondrial membrane potential and SOD activity of myocardial mitochondria in group IP and group PC was significantly higher than that in group IR(P<0.05). The protective effect of PC against I/R injury was partially counteracted by 5-HD .Conclusion Ischemic posteonditioning can protect the heart from I/R injury, this is supported by improvement mitochondrial ultrastructure and by decreasing apoptosis, increasing mitochondrial membrane potential and SOD activity, alleviating Ca~(2+) overload and decreasing MDA content in myocardial mitochondria. The cardio protective effects may be explained by mitochondrial ATP sensitive potassium channel.
10.Effects of heptanol preconditioning on structure, function and Cx43 content of mitochondria in rabbit model of myocardial ischemia/reperfusion injury
Yan HE ; Guoqiang ZHONG ; Zhiyu ZENG ; Weike LI ; Wei LI ; Jinyi LI
Chinese Journal of Pathophysiology 2010;26(3):461-465
AIM: To investigate the effects of heptanol preconditioning on the changes of structure, function and connexin 43 (Cx43) content in mitochondria in a rabbit model of myocardial isehemia-reperfusion (IR) injury. METHODS: In anesthetized open-chest rabbits, the left anterior descending artery (LAD) was occluded for 30 min and reperfused for 4 h. Sixty-four rabbits were randomly divided into 4 groups (n=16 in each group): sham operation group (sham group), ischemia-reperfusion group (IR group), ischemic preconditioning group (IP group) and heptanol preconditioning group (HT group). All rabbits in the 4 groups were killed 4 h after reperfusion. Myocardial infarct size was determined at the end of the experiment. Mitochondria was isolated by centrifugations. The ultrastructural changes of the mitochondria were observed under electronic microscope. The mitochondrial membrane potential, Ca~(2+) concentration, MDA content and SOD activity of myocardial mitochondria were also examined. The content of mitochondria Cx43 was detected by Western blotting. RESULTS: Compared to IR group, the myocardial infarct size was significantly reduced in IP (18.97%±2.80%) and HT (19.97%±3.80%) groups, the damage of mitoehondrial ultrastructure was milder (P<0.05), mitochondrial membrane potential was significantly higher and Ca~(2+) concentration was much lower (P<0.01) in IP group and HT group. No significant difference of MDA content and SOD activity in myocardial mitochondria between IR group and HT group was found. However, MDA content were much lower and SOD activity was significantly higher in IP group as compared to IR group (P<0.01). Compared to sham group, the mitochondria Cx43 expression was distinctly decreased compared to IR group (P<0.05) and no significant difference was found between IP group and HT group (P>0.05). CONCLUSION: Heptanol preconditioning protects myocardium from ischemia-reperfusion injury. The mechanism may be related to increasing in mitochondrial membrane potential, alleviating Ca~(2+) overload in myocardial mitochondria and attenuating the decrease in mitochondria Cx43 expression induced by isehemia-reperfusion.