ABSTRACT
Objective@#To evaluate the role of spinal COX-1 and COX-2 in remifentanil-induced hyperalgesia in mice with incisional pain.@*Methods@#Thirty-two male C57BL/6J mice, aged 8-10 weeks, weighing 20-25 g, were divided into 4 groups (n=8 each) using a random number table method: control group (group C), incisional pain plus remifentanil group (group IR), incisional pain plus remifentanil plus selective COX-1 inhibitor group (group IR+ SC560), and incisional pain plus remifentanil plus selective COX-2 inhibitor group (group IR+ SC236). In IR, IR+ SC560 and IR+ SC236 groups, normal saline 10 μl, SC560 25 μg and SC236 25 μg were intrathecally injected, respectively, 15 min later remifentanil 10 μg/kg was injected via the tail vein for 4 times at 15 min intervals.An incisional pain model was established after the first injection of remifentanil.The mechanical paw withdrawal threshold (MWT) was measured at 24 h before normal saline or remifentanil injection and 3, 6, 24 and 48 h after the last injection (T0-T4). The mice were sacrificed after the last measurement of pain threshold, and the L4-6 segments of the spinal cord were removed for determination of the expression of COX-1 and COX-2 (by Western blot) and expression of COX-1 and COX-2 mRNA (by quantitative real-time polymerase chain reaction).@*Results@#Compared with group C, the MWT was significantly decreased, and the expression of COX-2 protein and mRNA was up-regulated in IR, IR+ SC560 and IR+ SC236 groups (P<0.05). Compared with group IR, the MWT was significantly increased in IR+ SC560 and IR+ SC236 groups (P<0.05). There was no significant difference in the MWT at each time point between IR+ SC560 and IR+ SC236 (P>0.05) .There was no significant difference in the expression of COX-2 protein and mRNA among group IR, group IR+ SC560 and group IR+ SC236 (P>0.05). There was no significant difference in the expression of COX-1 protein and mRNA among the four groups (P>0.05).@*Conclusion@#Compared with COX-1, spinal COX-2 plays a major role in the pathophysiological mechanism of remifentanil-induced hyperalgesia in mice with incisional pain.
ABSTRACT
Objective To evaluate the role of spinal COX-1 and COX-2 in remifentanil-induced hyperalgesia in mice with incisional pain.Methods Thirty-two male C57BL/6J mice,aged 8-10 weeks,weighing 20-25 g,were divided into 4 groups (n =8 each) using a random number table method:control group (group C),incisional pain plus remifentanil group (group IR),incisional pain plus remifentanil plus selective COX-1 inhibitor group (group IR+SC560),and incisional pain plus remifentanil plus selective COX-2 inhibitor group (group IR+SC236).In IR,IR+SC560 and IR+SC236 groups,normal saline 10 μl,SC560 25 μg and SC236 25 μg were intrathecally injected,respectively,15 min later remifentanil 10 μg/kg was injected via the tail vein for 4 times at 15 min intervals.An incisional pain model was established after the first injection of remifentanil.The mechanical paw withdrawal threshold (MWT) was measured at 24 h before normal saline or remifentanil injection and 3,6,24 and 48 h after the last injection (T0-T4).The mice were sacrificed after the last measurement of pain threshold,and the L4-6 segments of the spinal cord were removed for determination of the expression of COX-1 and COX-2 (by Western blot)and expression of COX-1 and COX-2 mRNA (by quantitative real-time polymerase chain reaction).Results Compared with group C,the MWT was significantly decreased,and the expression of COX-2 protein and mRNA was up-regulated in IR,IR+SC560 and IR+SC236 groups (P＜0.05).Compared with group IR,the MWT was significantly increased in IR+SC560 and IR+SC236 groups (P＜0.05).There was no significant difference in the MWT at each time point between IR+SC560 and IR+SC236 (P＞0.05).There was no significant difference in the expression of COX-2 protein and mRNA among group IR,group IR+SC560 and group IR+SC236 (P＞0.05).There was no significant difference in the expression of COX-1 protein and mRNA among the four groups (P＞0.05).Conclusion Compared with COX-1,spinal COX-2 plays a major role in the pathophysiological mechanism of remifentanil-induced hyperalgesia in mice with incisional pain.
ABSTRACT
Objective To investigate the influence of ursolic acid on vascular endothelial growth factor ( VEGF) , cycloxygen-ase-2 (COX-2), and matrix metalloproteinases-2 (MMP-2) expressed in the mouse retinal ischemic model , and to explore the mecha-nisms of anti-angiogenesis.Methods Sixty 7-day clean-class C57BL/6J mice were divided randomly into 6 groups [ n =10 mice (20 eyes) per group]:blank control, model control (PBS), positive control (triamcinolone), and ursolic acid (UA) intervention (low-dose, medium-dose, and high-dose).Mice in the blank control group were raised in air , and mice in other groups in(75%±2%)O2 high-oxygen environment for 5 consecutive days .Mice in the model control group and breastfeeding mice were put back in air environ-ment (21%O2 ) on the 12th day after the new-born mice to induce the generation of retinal neovascularization .When models were suc-cessful, the drug treatments were applied immediately to the corresponding groups , with injection of 3μl of sterile PBS in model control group, 3 μl of 1.5, 3.00 and 6.0 μg UA in UA intervention group, and 3 μl of triamcinolone (1 ml∶40 mg) in positive control group, respectively.All mice were killed after overdose anesthesia on the 17th day.Their eyeballs were made into samples and retinal tissue pathological sections with H-E dying method.The positive expressions of VEGF , COX-2, and MMP-2 were detected with immu-nohistochemical method .The fresh retinal tissue homogenate was prepared to detect the protein expressions of VEGF , COX-2, and MMP-2 in retinal tissue with western blot method ,and mRNA expressions of VEGF , COX-2, and MMP-2 were detected with real-time fluorescent quantitative polymerase chain reaction ( RT-PCR) .Results According to protein and mRNA expressions of VEGF , COX-2,and MMP-2 in retinal tissue among six groups , protein expressions of VEGF , COX-2, and MMP-2 in model group were significantly higher than those in blank group ( P 0.05 ) .Each protein expression in the high UA intervention group was significantly lower than that in the low UA intervention group( P <0.05).Conclusions UA inhibited expressions of VEGF, COX-2, and MMP-2 in retinal ischemia model .UA also played an inhibitory role in the formation of neovascularization , and this role was positively correlated with UA dose .
ABSTRACT
Objective To observe selective cyclooxygenase-2 (COX-2) inhibitor celecoxib on the cell migration, MMP-9 and VEGF expression of human gastric cancer SGC-7901. Methods In vitro culture of SGC-7901 cells, the cells were divided into blank control group and celecoxib treatment group (different concentrations of celecoxib 25, 50 and 100μmol/L). SGC-7901 cells were treated with celecoxib for 24 h. The effect of celecoxib on cell migration of SGC-7901 was detected by the damage repair experiment. RT-PCR assay was used to detect the effect of celecoxib on MMP-9 mRNA and VEGF mRNA expressions in SGC-7901 cells. Results The migration distance of SGC-7901 cells was decreased with the increased concentration of celecoxib. There were significant differences between medium-dose and high-dose celecoxib groups and the control group. RT-PCR assay showed that MMP-9 mRNA and VEGF mRNA expressions in gastric cancer SGC-7901 were significantly decreased with the increased concentration of celecoxib, and there was a significant difference compared with those of control group (P＜0.05). Conclusion Celecoxib can inhibit migration of human gastric cancer SGC-7901 cells, which may be related to the inhibition of COX-2 downstream of MMP-9 and VEGF expressions.
ABSTRACT
Objective To investigate the role of cyclooxygenases (COXs) in the up-regulation of the expression of P2X3 receptors in the dorsal root ganglion (DRG) in rats with neuropsthic pain. Methods Twenty-four male SD rats, weighing 250-280 g, were randomly divided into 4 groups ( n = 6 each): sham operation group (group S), chronic constrictive injury (CCI) group, COX-1 inhibitor ibuprofen group (group Ⅰ), and COX-2 inhibitor celecoxib group (group C). Neuropathic pain was induced by CCI. The animals were anesthetized with intraperitoneal 10% chloral hydrate 300-500 mg/kg. CCI was produced by placing 4 ligatures on the left sciatic nerve at 1 mm intervals. In group S, the left sciatic nerve was only exposed but not ligated. In groups Ⅰ and C, ibuprofen 40 mg·kg-1 ·d-1 and celecoxib 30 mg·kg-1 ·d-1 were given through a gastric tube into the stomach at day 3-14 after operation respectively. Paw withdrawal latency (PWL) and paw withdrawal threshold (PWT) were measured before operation (baseline), and at 3, 5, 7, 10 and 14 days after operation. Then the rats were sacrificed and their L()-6 DRGs were removed to detect the expression of P2X3 mRNA and protein. Results Compared with group S, PWL was significantly shortened, PWT decreased, and P2X3 mRNA and protein expression up-regulated in group CCI ( P ＜ 0.05＝. Compared with group CCI, PWL was significantly prolonged, PWT increased, and P2X3 mRNA and protein expression down-regulated in groups Ⅰ and C (P ＜0.05＝. Compared with group Ⅰ, PWL was significantly prolonged, PWT increased, and P2X3 mRNA and protein expression up-regulated in group C ( P ＜0.05＝. Conclusion COXs are involved in the up-regulation of the expression of P2X3 receptors in the DRG in rats with neuropathic pain, and the effect of COX-1 is stronger than that of COX-2.
ABSTRACT
Objective To investigate the role of cyclooxygenase-2(COX-2)and mitochondrial adenosine tuiphosphate sensitive potassium channels (mito-KATP channels) in sufentanil preconditioning-induced delayed cardiopreteetion against myocardial ischemia-reperfnsion (I/R) injury in rats. Methods Seventy-two adult male Wistsr rats weighing 250-300 g were randomly divided into 6 groups ( n =12 each). Group Ⅰ,Ⅱ,Ⅲ were preconditioned with intraperitoneal (IP) normal saline (NS) 1 ml/kg while group Ⅳ,Ⅴ,Ⅵ with IP sufentanil 20 μg/kg at 24 h before myocardial ischemia. Group Ⅱ and Ⅴ were given IP NS-398 ( COX-2 inhibitor) 5 mg/kg at 30 rain before myocardial ischemla while group Ⅲ and Ⅵ were given intravenous 5-HD (mito-KATP channelblocker) 10 mg/kg at 10 min before ischemia or before being killed. Six animals in each group underwent 45 min myocardial ischemia followed by 120 min reperfusion, while the other six animals in each group were killed immediately before ischemia for determination of myocardial COX-2 expression and myocardial PGF2 and PGF1α content. Myocardial ischemia was induced by occlusion of left anterior descending branch (LAD) of coronary artety for 45 rain followed by 120 min reperfusion. MAP and HR were recorded immediately before ischemia (T0), at 15, 30, 45 rain of ischemia (T1-3) and at 30, 60, 90, 120 vain of reperfusion (T4-7). Heart rate-blood pressure product (RPP) was calculated. Arterial blood samples were obtained at T0.3 and T7 for measurement of plasma CK-MB activity. The animals were killed at the end of 120 nan reperfusion. The hearts were removed for determination of myocardial infarct area (IA) and area at risk (AAR). LA/AAR was calculated. Results There was no significant difference in HR, MAP and RPP at all time points among the 6 groups. Preconditioning with sufentanil significantly decreased plasma CK-MB activity at T3 and T7 and IA/AAR in group Ⅳ as compared with group Ⅰ.Myocardial COX-2 expression was up-regulated and PGE2 and PGF1α, contents were elevated by sufentanil preconditioning in group Ⅳ as eomared with control group (Ⅰ). In group Ⅴ and Ⅳ preconditioning with NS-398/5-HD significantly increased plasma CK-MB concentration and IS/AAB as compared with group Ⅳ, indicating involvement of COX-2 and mito-KATP channels in the sufentanil-induced delayed cardioprotection.The myocardial PGE2 and PGF1α contents were significantly reduced in group Ⅴ as compared with group Ⅳ. There was no significant difference in the myocardial COX-2 expression among group Ⅳ, Ⅴ and Ⅵ. Conclusion Both COX-2 and mito-KATP channels are involved in sufentanil preconditioning-induced delayed cardiopmtection.
ABSTRACT
Objective To investigate the effect of angiotensin Ⅱ (AngⅡ) type 1 receptor block irbesartan on the expression of renal cyclooxygenase-2 ( COX-2 ) in rats with type 2 diabetes mellitus.Methods 18 rats were divided into control group, diabetes mellitus group and treating group.Immunohistochemistry was used to measure the expression of COX-2, matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1).The urinary TXB2,6-Ket-PGF1 αconcentration was determined by radioimmunoassay at the 6th week .Results There was an increasing expression of COX-2,TIMP-1 and decreasing M MP-9 ( COX-2:0.39 ± 0.02 vs 0.24 ± 0.04, TIMP :0.41 ± 0.03 vs 0.24 ± 0.02,MMP-9:0.24 ± 0.02 vs 0.32 ± 0.02, P ＜ 0.05 ) expression in the diabetes mellitus group ( P ＜ 0.05 ).Irbesartan could increase MMP-9 (0.29 ± 0.03 ) and depress TIMP-1 (0.34 ± 0.02) expression through inhibiting the expression of COX-2(0.31 ± 0.03) in renal tissue.Conclusions COX-2 was involved in the pathogenesis of the injury of type 2 diabetic nephropathy.Irbesartan might exert its renoprotective effects through inhibiting COX-2 activity, modulating the expression of MMP-9 and TIMP-1.
ABSTRACT
Objective To detect COX-2 mRNA in cervical cancer and normal cervix, and explore the pathogenesis of adenocarcinoma of the uterine cervix. Methods COX-2 expression was detected by RT-PCR to explore the relationship between COX-2 and the adenocarcinogenon of cervical cancer in 36 cases of adenocarcinoma of the uterine cervix and 15 cases normal cervical tissue. Results The positive rate of COX-2 mRNA in adenocarcinoma of the uterine cervix tissues (55.6%) was higher than that of normal tissues ( 20. 0% ), the difference was significant ( P ＜ 0. 05). The expression of COX-2 mRNA was associated with stages and clinical grading of tumor ( P ＜ 0. 05), but no significant difference was found between stages and clinical grading of uterine cervix adenocarcinoma( P ＞ 0. 05). Conclusion The hyper expression of COX-2 mRNA in uterine cervix adenocarcinoma took part in the carcinogenesis of tumor.
ABSTRACT
Objectiye To explore the expression of COX-2 and VEGF and its clinical significance in non-Hodgkin lymphoma (NHL). Methods The expression of COX-2 and VEGF were detected by immunohistochemistry in 42 cases of NHL and 20 cases of lymph node with benign pathological change. Results The positive rate of COX-2 and VEGF was 45.24% and 73.81% in NHL respectively. The expression rate of VEGF was positively correlated with that of COX-2 in tissues of NHL ( x2 = 4. 63, P ＜ 0. 05).The expression of COX-2 was related to clinical stage and histopathologic grade of NHL ( x2 = 5.43, P ＜0. 05), but it had no association with gender, age, B symptoms, and IPI. The expression of VEGF was significantly related with aggression, B symptoms and IPI ( x2 =8. 979, 8. 893,6. 434, P ＜0. 05), but it had no association with age, gender and clinical stages. Conclusion COX-2 and VEGF may be involved in NHL tumorgenesis, and COX-2 may accelerate angiogenesis by increasing VEGF expression. Specific COX-2 inhibitors may be a novel therapeutic approach for NHL.
ABSTRACT
Objective To investigate the effects of Celecoxib,a selective COX-2 inhibitor,on the healing of gastric ulcer in rats,and reveal the rale of ERK signal transduction pathway in the mechanism of delaying the healing of gastric ulcer.Methods Forty-eight rats were randomly divided into model group(n=40) and sham operation group(n=8).In the rats in model group acetic acid-induced gastric ulcer was reproduced,while in sham operation group,rats underwent the sham procedure.Eight rats in sham-operation group and eight rats in model group were euthanized three days after the procedure.The other thirty-two rats in model group were divided into two subgroups including Celecoxib group and NS group(n=16).Three days after the procedure,rats in Celecoxib group received a gavage of 0.2% Celecoxib solution,and those in NS group received equal amount of 0.9% NaCl solution.Rats in Celecoxib group and NS group were euthanized on sixth and ninth day after ulcer induction(8 rats at each time point in each group).The effects of Celecoxib on the healing of gastric ulcer were observed.Its effects on the activity of Raf-1 and ERK1/2,and the expression level of two transcription factors c-Fos and c-Jun were also determined by Western blot analysis.Results Nine days after ulcer induction,the ulcer area was 11.9?3.1mm2 and 19.7?3.8mm2 in NS group and Celecoxib group,respectively,and they were much smaller than those on third day(P