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OBJECTIVE@#To investigate the changes in the expression of voltage-gated potassium channel subunit KCNA2 in the dorsal root ganglion (DRG) neurons of rats with osteoarthritis (OA) pain induced by sodium monoiodoacetate and explore the mechanism.@*METHODS@#A total of 156 adult male Sprague-Dawley rats were randomly divided into blank control group, saline group and intra-articular monoiodoacetate injection-induced OA group. The paw withdrawal mechanical threshold (PWMT) was measured before and at 1, 2, 4, and 6 weeks after monoiodoacetate injection. At 4 weeks after the injection, the pathological changes in the knee joints were analyzed using HE staining and Safranin O-Fast Green staining, and the expression of activating transcription factor 3 (ATF-3) and inducible nitric oxide synthase (iNOS) in the DRG neurons were detected by immunofluorescence staining. The expression of mRNA in the DRG neurons was detected by RT-qPCR at 1, 2, 4 and 6 weeks after the injection. The expression of KCNA2 in the DRG was measured by Western blotting, and the methylation level of promoter region was measured by MSPCR at 4 weeks after the injection.@*RESULTS@#The PWMT of the rats in OA group was significantly decreased at 2, 4, and 6 weeks after the injection as compared with the baseline ( < 0.05 or < 0.001) as well as the control group ( < 0.05 or < 0.001). Four weeks after the intra-articular injection, fractures and defects on the surface of the articular cartilage, bone hyperplasia, and blurred tidal line were observed in the rats in OA group, but no obvious pathological changes were detected in the control or saline groups. Compared with those in the control group, the expressions of ATF-3 and iNOS were significantly increased ( < 0.01) at 4 weeks after injection; the expression of mRNA at 2, 4 and 6 weeks and the expression of KCNA2 protein at 4 weeks were all significantly decreased ( < 0.05 or < 0.01), and the methylation level of gene was significantly increased at 4 weeks after the injection in OA group ( < 0.01).@*CONCLUSIONS@#The expression of KCNA2 is decreased in the DRG neurons of rats with OA pain likely as a result of enhanced methylation of promoter region.
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Animals , Male , Rats , Disease Models, Animal , Ganglia, Spinal , Knee Joint , Metabolism , Osteoarthritis , Metabolism , Pain , Metabolism , Promoter Regions, Genetic , Rats, Sprague-DawleyABSTRACT
Objective To evaluate the role of different opioid receptors in morphine postconditioning-induced reduction of ischemia-reperfusion (Ⅰ/R) injury in isolated rat hearts.Methods Healthy adult male Sprague-Dawley rats,aged 7-8 weeks,weighing 250-300 g,were anesthetized with chloral hydrate.The hearts were removed and retrogradely perfused with oxygenated K-H solution in a Langendorff apparatus.Forty-eight Langendorff-perfused rat hearts were divided into 4 groups (n=12 each) by a random number table method:Ⅰ/R group,morphine postconditioning group (M group),δ receptor antagonist naltrexone plus morphine postconditioning group (N+M group) and κ receptor antagonist nor-binaltorphimine plus morphine postconditioning group (B+M group).Hearts were subjected to 4 cycles of perfusion with K-H solution containing 1 μmol/L morphine for 15 s and then with K-H solution containing no morphine for 15 s in group M.In N+M group and B+M group,hearts were perfused with 5 μmol/L naltrindole and 5 μmol/L nor-binaltorphimine,respectively,starting from 10 nin of equilibration until 5 min of reperfusion,and morphine postconditioning was similar to those previously described in group M.Heart rate and the maximum rate of increase or decrease in left ventricular pressure (±dp/dtmax) were recorded at 20 min of equilibration and 30 and 60 nin of reperfusion.Corona~ effluent was collected at 20 min of equilibration and 60 min of reperfusion for measurement of the activity of creatine kinase by colorimetric assay.Eight hearts were obtained at 60 min of reperfusion for determination of myocardial infarct size.Four hearts were obtained at 60 min of reperfusion for detection of the expression of microtubule-associated protein 1 light chain 3 Ⅰ (LC3 Ⅰ) and LC3 Ⅱ by Western blot.LC3 Ⅱ/LC3 Ⅰ ratio was calculated.Results Compared with the baseline value at 20 min of equilibration,heart rate and +dp/dt were significantly decreased at 30 and 60 min of reperfusion,and the activity of creatine kinase in coronary effluent was increased at 60 min of reperfusion in four groups (P＜0.05).Compared with group Ⅰ/R,the activity of creatine kinase in coronary effluent,percentage of myocardial infarct size and LC3 Ⅱ/LC3 Ⅰ ratio were significantly decreased in group M (P＜0.05).Compared with group M,the activity of creatine kinase in coronary effluent,percentage of myocardial infarct size and LC3 Ⅱ/LC3 Ⅰ ratio were significantly increased in N+M and B+M groups (P＜0.05).Conclusion δ and κ opioid receptors are involved in morphine postconditioning-induced reduction of Ⅰ/R injury in isolated rat hearts,and the mechanism may be related to inhibiting the level of autophagy.
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Objective To evaluate the effect of dexmedetomidine on the intestinal mucosal injury in the patients undergoing cardiac valve replacement with cardiopulmonary bypass (CPB).Methods Forty patients of both sexes with rheumatic heart disease,aged 32-64 yr,weighing 40-75 kg,of ASA physical status Ⅱ or Ⅲ (NYHA class Ⅱ or Ⅲ),scheduled for elective cardiac valve replacement with CPB,were randomly divided into 2 groups (n =20 each) using a random number table:control group (group C) and dexmedetomidine group (group D).After induction of anesthesia,the patients were endotracheally intubated and mechanically ventilated.Anesthesia was maintained with 0.8％-2.0％ sevoflurane inhalation and intermittent iv boluses of sufentanil 0.5-1.0 μg/kg and vecuronium 0.04-0.06 mg/kg.Before routine induction of anesthesia,a loading dose of dexmedetomidine 1 μg/kg was injected intravenously over 10 min,followed by continuous infusion at 0.3 μg · kg-1 · h-1 until the end of surgery in group D,while the equal volume of normal saline was given in group C.Before CPB,at 30 min after aortic clamping,at the termination of CPB,at the end of surgery and at 6 and 24 h after surgery,central venous blood samples were taken for determination of concentrations of tumor necrosis factor-alpha,interleukin-6 (IL-6) and IL-10 and intestinal fatty acid binding protein in plasma (by ELISA),and the plasma concentration of endotoxin (using turbidimetry).The time of postoperative mechanical ventilation and duration of ICU stay were recorded.Results Compared with group C,the concentrations of tumor necrosis factor-alpha,IL-6,IL-10 and endotoxin and intestinal fatty acid binding protein in plasma were significantly decreased,and the time of postoperative mechanical ventilation and duration of ICU stay were shortened in group D.Conclusion Dexmedetomidine infused continuously at 0.3 μg · kg-1 · h-1 (until the end of surgery) after a loading dose of 1 μg/kg before routine induction of anesthesia can reduce intestinal mucosal injury in the patients undergoing cardiac valve replacement with CPB.
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Objective To examine how early life exposure to famine would impact on liver and kidney functions and related chronic metabolic diseases during adulthood.Methods A random cluster sampling method was adopted in Anhui province,2011 from a physical examination center,in a first-class hospital.4 252 study subjects were born between 1957 and 1963.According to the time of birth:the study subjects were divided into three groups,respectively:1957-1958 (983 persons as pre-famine),1959-1961 (1 247 persons as exposed to famine) or 1962-1963 (2 022 persons as controls,also the post-famine).Variances between groups AST,ALT,r-GGT,differences in the levels of SCr,UA,UREA and the change trend were compared.Results ALT,IBIL,TBIL,SCr,UREA were statistically different (P＜0.05) among subjects born in the different years.r-GGT,ALT,AST,ALB,SCr were statistically different (P＜0.05) among males bornin different years so as the r-GGT,AST,ALB,GLB,TP,SCr,UA,UREA in females (P＜0.05).r-GGT,ALT,ALB,SCr differences statistically significant (P＜0.05) and r-GGT,AST,ALB,GLB,TP,SCr,UA,UREA in females were statistically significantly different (P＜0.05).Conclusion Early life poor nutrition could lead to developmental disorders,organ function damage in liver and kidney function during adulthood.Women appeared to have balanced diet nutrition during pregnancy which was far important in the prevention on adulthood chronic metabolic diseases.
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ObjectiveTo investigate the role of phosphatidylinositol 3-kinase/protein-serine-threonine kinases (PI3K-Akt) signal pathway in the protection of myocardium against ischemia-reperfusion (I/R) injury by diasoxide postconditioning in rats.MethodsThirty-six male SD rats weighing 250-300 g were randomly divided into 4 groups using random number table (n =9 each):group I/R; group diazoxide (group D); group wortmannin (PI3K inhibitor) (group W) and group wortmannin + diazoxide (group WD).The animals were anesthetized with intraperitoneal 10％ chloral hydrate 4 ml/kg,intubated and mechanically ventilated.Myocardial I/R was produced by 30 min occlusion of left anterior descending coronary artery followed by 120 min reperfusion.0.1％ dimethyl sulfoxide (the vehicle for diazoxide and wortmannin)/diazoxide at 0.47 mg· kg-1 · min-1/wortmannin at 1 μg·kg-1 ·min-1 was infused for 15 min starting from 25 min of ischemia in groups I/R,D and W respectively.In group DW wortmannin was infused at 5 min before diazoxide infusion.Blood samples were collected from left ventricle at the end of 120 min reperfusion for measurement of lactate dehydrogenase (LDH) activity.Myocardial infarct size was measured.Myocardial specimens were obtained for determination of apoptosis index (the number of apoptotic cells/the total number of cells examined) and expression of Bcl-2 and Bax.Bcl-2/Bax ratio was calculated.ResultsDiazoxide postconditioning significantly decreased plasma LDH activity,myocardial infarct size,apoptosis index and Bax expression in myocardium and increased myocardial Bcl-2 expression and Bcl-2/Bax ratio in group D compared with group I/R.Wortmannin partly counteracted the protective effects of diazoxide postconditioning against myocardial infarct.There was no significant difference in the above variables between groups I/R and W.ConclusionPI3K-Akt signal pathway is involved in the protective effects of diazoxide postconditioning on myocardium against I/R injury.