OBJECTIVETo investigate the effects of glucocorticoid receptor antagonist-M8046 on the behavior and the cyclooxygenase-2/prostaglandin E2( COX-2/PGE2) expression in spinal cord dorsal horn and dorsal root ganglia (DRG) in chronic constrictive injury (CCI) rats.

METHODSOne hundred and forty-four male SD rats were randomly divided into 4 groups, 36 rats in each group: Sham operation group (Sham), chronic constrictive group (CCI), M8046 treated group (M8046) and solvent controlled group (Sc). M8046 3 mg/(kg x d) intraperitoneal injection was given after operation in group M8046. Paw thennal withdrawal (PTWL) and paw mechanical withdrawal threshold (PMWT) of rats were measured on 2 pre-operative and 1, 3, 7, 10, 14 post-operative days. The spinal cord and L15 DRG of the operated side was removed at 3, 7, 14 days after surgery. The change of COX-2 and PGE2 expression was determined by immunohistochemical staining and ELISA separately.

RESULTSPTWL and PMWT in CCI group were significantly lower than those in Sham group on every post-operative day (P < 0.05). PTWL and PMWT in M8046 group were significantly higher than those in CCI group on 7, 10, 14 post-operative day (P < 0.05). In spinal dorsal horn, the level of COX-2 and PGE2 expression in CCI group was significantly higher than that in Sham group (P < 0.05). M8046 could significantly attenuate the activation of COX-2 and PGE2 induced by CCI (P < 0.05). The expression of COX-2 and PGE2 in DRG was similar to that in spinal dorsal horn.

CONCLUSIONThe effects of M8046 ameliorate the CCI-induced neuropathic pain may be related to attenuate the expression of COX-2 and PGE2 in spinal cord and DRG.

Animals ; Cyclooxygenase 2 ; metabolism ; Dinoprostone ; metabolism ; Ganglia, Spinal ; drug effects ; metabolism ; Male ; Neuralgia ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, Glucocorticoid ; antagonists & inhibitors ; Spinal Cord ; drug effects ; metabolism

AIMTo explore the effects of intrathecal injection of selective cyclooxygenase-1 (COX-1) inhibitor, SC-560, on mechanical allo dynia and spinal ERK protein expression in rats with postoperative pain.

METHODSRats were divided into 4 groups: control group, postoperative pain group, SC-560 group and DMSO group. Mechanical withdrawal threshold (MWT), immunohistochemical and Western blotting technique were used to evaluate mechanical hypersensitivity and the expression of phospho-ERK in the spinal cord, respectively.

RESULTS(1) Behavior test rats developed allodynia 1 h after operation and SC-560 100 microg administrated intrathecally demonstrated a significant reduction in postoperative hypersensitivity. (2) Immunohistochemical staining Phospho-ERK positive neurons in the rat superficial spinal dorsal horn increased significantly 1 h after incision compared with that of non-incision group. Intrathecal administration of SC-560 preoperatively could significantly reduce the number of phospho-ERK positive neurons. (3) Western blot expression of phospho-ERK1/2 protein in the lumbar spinal cord increased significantly 1 h after incision and decreased by intrathecal injection of SC-560.

CONCLUSIONSC-560 administrated intrathecally can inhibit mechanical hypersensitivity induced by postoperative pain in rats and this anti-allodynic process may mediated by spinal ERK.

Animals ; Cyclooxygenase Inhibitors ; pharmacology ; Extracellular Signal-Regulated MAP Kinases ; metabolism ; Male ; Pain Measurement ; drug effects ; Pain, Postoperative ; metabolism ; Pyrazoles ; pharmacology ; Rats ; Rats, Wistar ; Spinal Cord ; drug effects ; metabolism

OBJECTIVETo investigate the dynamic changes of neurofilaments (NFs) proteins in spinal cords of hens with phenylmethylsulfonyl fluoride (PMSF) pretreatment for exploring the mechanism of tri-o-cresyl phosphate (TOCP)-induced delayed neuropathy (OPIDN).

METHODAdult Roman hens were randomly divided into three groups, control, TOCP and PMSF + TOCP. Birds in PMSF + TOCP set were pretreated with PMSF, 24 hours later, hens in both TOCP group and PMSF + TOCP group were administrated with TOCP at a single dosage of 750 mg/kg. Then all animals were sacrificed on the corresponding time-points of 1, 5, 10, and 21 days respectively after dosing of 750 mg/kg TOCP. The spinal cords were dissected, homogenized, and centrifuged at 100,000 x g. The levels of high molecular neurofilament (NF-H), medium molecular neurofilament (NF-M) and low molecular neurofilament (NF-L) in both pellet and supernatant fractions of spinal cords were determined by SDS-PAGE and Western-blotting.

RESULTSThe hens in TOCP group showed paralysis gait at the end of 21-day experimental period. The levels of NFs proteins in spinal cords changed obviously. Compared with control, the NFs in pellet showed a dramatic decrease on day 10 and then followed by a recovery. In the supernatant, the NFs proteins showed similar changes, which decreased significantly on day 10 and almost recovered control on day 21. Such as, NF-L, NF-M and NF-H decreased by 51%, 86% and 38% on day 10. The OPIDN signs were not observed in PMSF + TOCP group, and imbalances of NFs were obviously alleviated. Compared with control, only NF-M in pellet increased by 21% (P < 0.05) on day 21, others remained no changes; The levels of NF-H and NF-M in supernatant respectively increased by 19% and 35% on day 21, others were no significant statistical differences.

CONCLUSIONTOCP may induce imbalance of NFs levels in progress of OPIDN, and PMSF pretreatment may protect animals from OPIDN by reducing above changes, which may explain that TOCP-induced imbalance of NFs may be connected with the occurrence and development of OPIDN.

Animals ; Chickens ; Female ; Neurofilament Proteins ; drug effects ; Phenylmethylsulfonyl Fluoride ; pharmacology ; Protein Subunits ; drug effects ; Spinal Cord ; drug effects ; metabolism ; pathology ; Tritolyl Phosphates ; toxicity

OBJECTIVETo study the effects of Ginkgo biloba extract (GBE) on lipid peroxidation and apoptosis after spinal cord ischemia/reperfusion (I/R) in rabbits.

METHODSSpinal cord I/R injury model was established according to the description of Erten et al. A total of 27 New Zealand white rabbits were divided into three groups randomly: a sham group (9 rabbits treated with sham operation but without aortic occlusion), a model group (9 rabbits treated with aortic occlusion and volume-matched saline), and a GBE group (9 rabbits treated with aortic occlusion and Ginaton (100 mg/kg) injected 30 minutes before aortic clamping and at the onset of reperfusion). The neurological outcomes were evaluated at 24 and 48 hours after reperfusion, respectively. The spinal cord malondialdehyde (MDA) level, superoxide dismutase (SOD) were then detected. Neural cell apoptosis was determined by terminal deoxynucleotidyl t-ransferase (TdT)-mediated dUTP-fluorescence nick end labeling (TUNEL) method and the expression of bcl-2 and bax were examined histologically in the spinal cord with immunohistochemistry.

RESULTSI/R produced a significant decrease in neurological scoring. The motor scores of the GBE group were significantly higher than those of the model group at 24 and 48 hours after reperfusion (P<0.05). Compared with the model group, GBE ameliorated the down-regulation of SOD and produced a significant reduction of the MDA level (P<0.01). The positive cells for TUNEL in the model group were much more than those of the GBE group (P<0.01). The bcl-2 was up-regulated after I/R, especially in the GBE group (P<0.01). The up-regulation of bax was greatly diminished by GBE (P<0.01).

CONCLUSIONSGBE has protective effects against spinal cord I/R injury, and the mechanism may be that it can scavenge oxygen free radicals and inhibit the apoptosis of neural cells.

Animals ; Apoptosis ; drug effects ; Ginkgo biloba ; Lipid Peroxidation ; drug effects ; Malondialdehyde ; analysis ; Neuroprotective Agents ; therapeutic use ; Phytotherapy ; Plant Extracts ; therapeutic use ; Rabbits ; Reperfusion ; Spinal Cord ; drug effects ; pathology ; Spinal Cord Ischemia ; metabolism ; pathology ; Superoxide Dismutase ; analysis

AIMTo observe mRNA expression of muscarinic acetylcholine receptors in spinal cord and brainstem in morphine dependent or withdrawal rats.

METHODSThe mRNA expression level of m1, m2, m3, m4 and m5 were determined by RT-PCR, the beta-actin mRNA expression was used as internal control.

RESULTSThe mRNA level of m1, m2, m3, m4 and m5 in spinal cord and m1 and m2 in brainstem were increased significantly during morphine dependence, and the levels of m1, m2, m3 and m4 in spinal cord and m1 in brainstem were decreased 1 h after the injection of naloxone (4 mg.kg-1, i.p.) in morphine dependent rats. Either scopolamine (0.5 mg.kg-1) or pirenzepine (10 mg.kg-1) was shown to significantly decrease the morphine withdrawal symptoms in rats. The levels of m1, m2, m3 and m5 in spinal cord were increased by pretreatment with pirenzepine and the levels of m2, m3 and m4 in spinal cord were increased by pretreatment with scopolamine.

CONCLUSIONThe adaptive expression of muscarinic receptors at spinal and supraspinal levels play important role in mediating morphine dependence and withdrawal in rats.

Animals ; Brain Stem ; drug effects ; metabolism ; Gene Expression ; drug effects ; Male ; Morphine ; toxicity ; Morphine Dependence ; metabolism ; RNA, Messenger ; biosynthesis ; drug effects ; Rats ; Rats, Sprague-Dawley ; Receptors, Muscarinic ; biosynthesis ; classification ; genetics ; Spinal Cord ; drug effects ; metabolism ; Substance Withdrawal Syndrome ; metabolism

OBJECTIVETo investigate the dynamic changes of neurofilament contents in rat's spinal cord induced by 2, 5-hexanedione (2, 5-HD), and explore the molecular mechanism of n-hexane neuropathy.

METHODSMale Wistar rats were administered at a dosage of 400 mg/kg/day 2, 5-HD for 2, 4 and 8 weeks respectively. HD-induced neurological defects were detected and quantified using gait score, and the relative lev-els of NF-H, NF-M, and NF-L in spinal cords of rats were determined by Western Blotting.

RESULTSExposure to 2, 5-HD produced progressive gait abnormalities, which suggested that the rat model of 2, 5-HD-induced neurotoxicity was established successfully. Western-Blotting results showed that NFs content in spinal cord demonstrated a progressive decline as the intoxication continued. In the supernatant fraction, compared to the controls, NF-H con-tent decreased by 15.7%, 57.0%, and 58.0% respectively after 2, 4, and 8-week treatment with 2, 5-HD (P < 0.01); accordingly, NF-M decreased by 36.0%, 61.3%, and 65.2% respectively (P < 0.01); NF-L decreased by 20.8%, 43.9%, and 44.3% respectively (P < 0.01). In the pellet fraction, the contents of NF-H in groups of 4 and 8 weeks' exposure to HD decreased by 35.6% and 43.2%, respectively (P < 0.01), and those of NF-L decreased by 26.4% and 42.1%, respectively (P < 0.01) when compared to the control. Further-more, NF-M contents in groups of 2, 4 and 8 weeks' exposure decreased by 23.3%, 33.9%, and 63.7% respectively (P < 0.01). The NFs level in spinal cords was highly correlated with gait abnormality of treated rats as the intoxication went on. Multiple correlation coefficients of NF-H, NF-M, and NF-L content with gait score of HD-treated rat were 0.8912, 0.9282 and 0.8981 (P < 0.01) respectively.

CONCLUSIONThe declines of NFs are high-ly related to neurobehavioral abnormality of 2, 5-HD-treated animals, and involved in the development of n-hexane neuropathy.

Animals ; Disease Models, Animal ; Gait ; drug effects ; Hexanones ; toxicity ; Male ; Neurofilament Proteins ; metabolism ; Rats ; Rats, Wistar ; Spinal Cord ; drug effects ; metabolism

OBJECTIVETo study the effect of GABA transporter (GAT-1) on the analgesic action of oxysophoridine (OSR) in the central nervous system of mice.

METHODHot plate test was used to observe and analyze the effect of gamma aminobutyric acid and the inhibitor of GAT-1 (NO-711) on the analgesic action of oxysophoridine. Real time RT-PCR was used to investigate the influence of OSR on the expression of GAT-1 mRNA induced by formalin in spinal cord and brain of mice.

RESULTBoth GABA (2.0 mg x kg(-1), icv) and NO-711(0.125 mg x kg(-1), icv) enhanced the analgesic action of OSR (32.0 mg x kg(-1), iv) in the hot plate test, and the latencies was markedly increased (P < 0.05, P < 0.01). OSR (500.0 mg x kg(-1), iv) significantly inhibited the expression of GAT-1 mRNA induced by formalin (P < 0.05).

CONCLUSIONGAT-1 was involved in the analgesia effect of OSR and the down-regulation of GAT-1 mRNA enhanced the analgesic effect.

Alkaloids ; pharmacology ; Analgesics ; pharmacology ; Animals ; Brain ; drug effects ; metabolism ; Down-Regulation ; drug effects ; Female ; GABA Plasma Membrane Transport Proteins ; genetics ; metabolism ; Gene Expression Regulation ; drug effects ; Male ; Mice ; RNA, Messenger ; analysis ; Spinal Cord ; drug effects ; metabolism

OBJECTIVETo observe effects of Tanshinone- II A sulfonate on expression of Nuclear factor-kappaB (NF-kappaB), Vascular Cell Adhesion Molecule-1 (VCAM-1) and hemorrheology during spinal cord ischemia reperfusion injury,and explore the function and mechnism.

METHODSFifty-four New Zealand rabbits (aged 3 months,weighted 2.0 +/- 0.2 kg) were randomly divided into 6 in sham group (lumbar artery were separated in operation,0.8 ml/kg saline were injected at 0.5 h before and after operation), 24 in ischemia group ( lumbar artery were clipped after seperation, and the same dose of saline), 24 in Tanshinone group (lumbar artery were clipped after seperation, and the same dose of Tanshinone- II A sulfonate) . Abdomincal aorta blood were drawed after treatment respectively at 0.5 h, 1 h, 4 h and 8 h, and tesetd whole blood viscosity [high cut (mpa.s)/150(l/s), middle cut (mpa.s)/60(l/s) and low cut (mpa.s)/10(l/s)], capillary plasma viscosity, red cell aggregation index, rigid index, deformation index and electrophoresis index. Spinal cord tissues were divided into two sections,one fixed in 4% paraformaldehyde, another stored in liquid nitrogen. Immunohistochemical method and ELISA were used to test change of content of NF-kappaB and VCAM-1.

RESULTS1) The expression of NF-kappaB in Tanshinone group were lowest, and in ischemia group were highest. 2) Compared with sham group, VCAM-1 in ischemia group at different time were obviously increased,especially at 0.5, 1 and 4 h (P<0.01), and had meaning at 8 h (P<0.05). Compare between Tanshinone group and ischemia group, VCAM-1 at 0.5 h were obviously decreased (P<0.01), and had meaning at 1 h, 4 h and 8 h (P<0.05). 3) There were no postive vasvular expression in sham group, and at 0.5 h in Tanshinone group and ischemia group. The highest postive vasvular expression in ischemia group were at 1 h, 4 h and 8 h, and had significant meaning at 1 h and 4 h between ischemia group and Tanshinone group (P<0.05), and 8 h were obviously most. 4) The whole blood viscosity in ischemia group at 10 s(-1), 60 s(-1), 150 s(-1) were highest, and capillary viscosity increased (P<0.05 or P<0.01). While capillary viscosity, red cell aggregation index, figid index, deformation index in Tanshinone group decreased obviously (P<0.01).

CONCLUSIONTanshinone-II A sulfonate can relieve spinal cord ischemia reperfusion injury by regulating expression of NF-kappaB, VCAM-1, decreasing whole blood viscosity, capillary plasma viscosity, red cell aggregation index, rigid index, and improve hemorhelogy.

Animals ; Female ; Gene Expression Regulation ; drug effects ; Hemorheology ; drug effects ; Male ; NF-kappa B ; metabolism ; Phenanthrenes ; pharmacology ; therapeutic use ; Rabbits ; Reperfusion Injury ; drug therapy ; metabolism ; physiopathology ; Spinal Cord ; drug effects ; metabolism ; physiopathology ; Vascular Cell Adhesion Molecule-1 ; metabolism

OBJECTIVETo study the effect of adenosine preconditioning on cell apoptosis and expressions of glucose-regulated protein (GRP-78) and cysteinyl aspartate-specific protease 12 (caspase-12) in rats with spinal cord ischemia-reperfusion injury.

METHODSTwenty-seven rats were randomized into 3 equal groups and subjected to sham operation (group A), spinal cord ischemia-reperfusion injury (group B), or ischemia-reperfusion injury with adenosine treatment. Spinal cord ischemia-reperfusion injury was induced by cross-clamping of the abdominal aorta inferior to the left renal artery. The spinal cord function was assessed using the Modified Tarlov Scale at 6, 12, and 24 h after reperfusion. At 24 h after reperfusion, histological analysis was carried out with HE staining; cell apoptosis and viability were determined with TUNEL staining, and the expressions of GRP-78 and caspase-12 proteins were determined with Western blotting.

RESULTSHE staining of the spinal cord showed extensive spinal cord injury such as cell edema in group B as compared with group C. Compared with group A, group B showed a significantly increased number of apoptotic cells; the number of apoptotic cells in group B was greater than that in group C. Compared with group B, group C showed significantly increased GRP-78 expression (P<0.01) and decreased caspase-12 expression (P<0.01).

CONCLUSIONAdenosine can up-regulate GRP-78 expression and down-regulate caspase-12 expression, and protects the spinal cord against ischemia-reperfusion injury by inhibiting cell apoptosis.

Adenosine ; pharmacology ; Animals ; Apoptosis ; drug effects ; Caspase 12 ; metabolism ; Heat-Shock Proteins ; metabolism ; Ischemic Preconditioning ; methods ; Male ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; metabolism ; Spinal Cord Ischemia ; metabolism

OBJECTIVEScorpion (Hemiscorpius lepturus) stings are a public health concern in Iran, particularly in south and southwestern regions of Iran. The gold standard for the treatment of a scorpion sting is anti-venom therapy. However, immunotherapy can have serious side effects, such as anaphylactic shock (which can sometimes even lead to death). The aim of the current study was to demonstrate the protective effect of ozone against toxicity induced by Hemiscorpius lepturus (H. lepturus) venom in mice.

METHODSEight hours after the injection of ozone to the experimental design groups, the male mice were decapitated and mitochondria were isolated from five different tissues (liver, kidney, heart, brain, and spinal cord) using differential ultracentrifugation. Then, assessment of mitochondrial parameters including mitochondrial reactive oxidative species (ROS) production, mitochondrial membrane potential (MMP), ATP level, and the release of cytochrome c from the mitochondria was performed.

RESULTSOur results showed that H. lepturus venom-induced oxidative stress is related to ROS production and MMP collapse, which is correlated with cytochrome c release and ATP depletion, indicating the predisposition to the cell death signaling.

CONCLUSIONIn general, ozone therapy in moderate dose can be considered as clinically effective for the treatment of H. lepturus sting as a protective and antioxidant agent.

Animals ; Brain ; drug effects ; metabolism ; Cytochromes c ; metabolism ; Heart ; drug effects ; Kidney ; drug effects ; metabolism ; Liver ; drug effects ; metabolism ; Male ; Membrane Potential, Mitochondrial ; drug effects ; Mice ; Mice, Inbred BALB C ; Muscle, Skeletal ; drug effects ; metabolism ; Myocardium ; metabolism ; Ozone ; pharmacology ; Scorpion Venoms ; toxicity ; Scorpions ; physiology ; Spinal Cord ; drug effects ; metabolism