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Experimental autoimmune prostatitis (EAP)-induced persistent inflammatory immune response can significantly upregulate the expression of N-methyl-D-aspartic acid (NMDA) receptors in the paraventricular nucleus (PVN). However, the mechanism has not yet been elucidated. Herein, we screened out the target prostate-derived inflammation cytokines (PDICs) by comparing the inflammatory cytokine levels in peripheral blood and cerebrospinal fluid (CSF) between EAP rats and their controls. After identifying the target PDIC, qualified males in initial copulatory behavior testing (CBT) were subjected to implanting tubes onto bilateral PVN. Next, they were randomly divided into four subgroups (EAP-1, EAP-2, Control-1, and Control-2). After 1-week recovery, EAP-1 rats were microinjected with the target PDIC inhibitor, Control-1 rats were microinjected with the target PDIC, while the EAP-2 and Control-2 subgroups were only treated with the same amount of artificial CSF (aCSF). Results showed that only interleukin-1β(IL-1β) had significantly increased mRNA-expression in the prostate of EAP rats compared to the controls (P < 0.001) and significantly higher protein concentrations in both the serum (P = 0.001) and CSF (P < 0.001) of the EAP groups compared to the Control groups. Therefore, IL-1β was identified as the target PDIC which crosses the blood-brain barrier, thereby influencing the central nervous system. Moreover, the EAP-1 subgroup displayed a gradually prolonged ejaculation latency (EL) in the last three CBTs (all P < 0.01) and a significantly lower expression of NMDA NR1 subunit in the PVN (P = 0.043) compared to the respective control groups after a 10-day central administration of IL-1β inhibitors. However, the Control-1 subgroup showed a gradually shortened EL (P < 0.01) and a significantly higher NR1 expression (P = 0.004) after homochronous IL-1β administration. Therefore, we identified IL-1β as the primary PDIC which shortens EL in EAP rats. However, further studies should be conducted to elucidate the specific molecular mechanisms through which IL-1β upregulates NMDA expression.
Subject(s)
Animals , Male , Rats , Cytokines/metabolism , Disease Models, Animal , Ejaculation/physiology , Interleukin-1beta/metabolism , N-Methylaspartate/metabolism , Prostate/metabolism , Prostatitis/metabolism , Receptors, N-Methyl-D-Aspartate/metabolismABSTRACT
To observe the cell origin of N-methyl-D-aspartic acid(NMDA)receptor expression in skin after chronic ischemic pain modeling in rats and explore the role of NMDA receptor in type Ⅰ complex regional pain syndrome. Forty-two adult male Sprague-Dawley rats were randomly divided into five groups:sham operation group(=12),chronic post ischemia pain(CPIP)group(=12),CPIP+normal saline(NS)group(=6),CPIP+NMDA group(=6),and CPIP+MK801 group(=6).Six rats in the sham operation group and CPIP group were sacrificed under deep anesthesia one day after modeling.The plantar skin and L3-L5 spinal cord tissue were used for NR1(NMDA receptor)subunit immunofluorescence detection and for Western blotting of NR1,interleukin(IL)-1β,and tumor necrosis factor(TNF)-α.For the remaining rats,the mechanical withdrawal threshold(MWT)values on the 2nd,6th,10th and 14th day after ischemia were recorded,and the corresponding drugs were injected subcutaneously from the 6th day after ischemia.The skin and L3-L5 spinal cords were collected on the 14th day,and the same detection methods were applied. Compared with the sham operation group,the CPIP group had significantly higher expressions of NR1(1.708±0.064;=12.120, <0.001),IL-1β(2.575±0.305;=5.158, =0.003),and TNF-α(2.691±0.217;=7.786, <0.001)in the skin on the first day after modeling.After intervention with NMDA and MK801,the MWT value was [(20.37±0.95)g] in the CPIP+NS group,which was significantly higher than that in CPIP+NMDA group [(15.85±1.09)g;=10.920, <0.001] but significantly lower than that in CPIP+MK801 group[(22.95±0.96)g;=6.421, <0.001] 10 days after modeling.On the 14th day,compared with the MWT of the CPIP+NS group [(21.57±0.96)g],the CPIP+NMDA group had significantly decreased MWT value [(16.53±1.63)g;=12.190, <0.001],and the CPIP+MK801 group had significantly increased MWT value [(23.27±1.28)g;=4.094, =0.025].Compared with the sham operation group,the CPIP group had significantly increased NR1 expression(1.708±0.064;=10.910, <0.001)and the CPIP+NS group had significantly increased expressions of IL-1β(2.518±0.147;=11.010, <0.001)and TNF-α(1.949±0.184;=10.870, <0.001).Compared with the CPIP+NS group,the CPIP+NMDA group had significantly increased expressions of IL-1β(4.816±0.607;=16.670, =0.003)and TNF-α(2.629±0.349;=7.790, <0.001)and the CPIP+MK801 group had significantly decreased expressions of IL-1β(1.048±0.257;=10.660, =0.003)and TNF-α(0.790±0.165;=13.280, <0.001). NMDA receptor activation in skin keratinocytes after chronic ischemia in rats hinders the expression of inflammatory cytokines such as IL-1β and TNF-α,which may be involved in central sensitization and pain conduction of type Ⅰ complex regional pain syndrome.
Subject(s)
Animals , Male , Rats , Interleukin-1beta , Keratinocytes , Pain , Rats, Sprague-Dawley , Receptors, N-Methyl-D-Aspartate , Spinal Cord , Tumor Necrosis Factor-alphaABSTRACT
Objective To investigate the effect of 17β-estradiol on the pain threshold in neuropathic rats.Methods Fifty fe-male SD rats were divided into five groups by adopting the random number table method,the sham operation group(separating and exposing the left sciatic nerve without ligation and giving the saline injection),the other four groups were established as chronic compression injury(CCI)model of sciatic nerve:CCI group(saline injection),estradiol group(17β-estradiol injection),antagonist group(AP-5 injection)and composite group(17β-estradiol and AP-5 injection),10 cases in each group.The rat mechanical pain threshold value was examined by adopting the paw withdrawal mechanical threshold(PWMT),the rat thermal threshold was exam-ined by adopting the paw withdrawal thermal latency(PWTL),and the expression of NMDAR1 protein was determined by immuno-histochemistry and Western blot.Results Compared with the sham operation group,PWM T in the CCI group and estradiol group was decreased(P<0.05)and PWTL was shortened(P< 0.05),while the expression of NMDAR1 protein was significantly in-creased(P<0.05).Compared with the CCI group,PWMT in the estradiol group was decreased(P<0.05)and PWTL was short-ened(P<0.05),while the expression of NMDAR1 protein was significantly increased(P<0.05).Conclusion 17β-estradiol can de-crease the pain threshold of the neuropathic pain rats by increasing the NMDAR1 expression.
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Differences in intravaginal ejaculation latency reflect normal biological variation, but the causes are poorly understood. Here, we investigated whether variation in ejaculation latency in an experimental rat model is related to altered sympathetic nervous system (SNS) activity and expression of N-methyl-D-aspartic acid (NMDA) receptors in the paraventricular nucleus of the hypothalamus (PVN). Male rats were classified as "sluggish," "normal," and "rapid" ejaculators on the basis of ejaculation frequency during copulatory behavioral testing. The lumbar splanchnic nerve activity baselines in these groups were not significantly different at 1460 ± 480 mV, 1660 ± 600 mV, and 1680 ± 490 mV, respectively (P = 0.71). However, SNS sensitivity was remarkably different between the groups (P < 0.01), being 28.9% ± 8.1% in "sluggish," 48.4% ± 7.5% in "normal," and 88.7% ± 7.4% in "rapid" groups. Compared with "normal" ejaculators, the percentage of neurons expressing NMDA receptors in the PVN of "rapid" ejaculators was significantly higher, whereas it was significantly lower in "sluggish" ejaculators (P = 0.01). In addition, there was a positive correlation between the expression of NMDA receptors in the PVN and SNS sensitivity (r = 0.876, P = 0.02). This study shows that intravaginal ejaculatory latency is associated with SNS activity and is mediated by NMDA receptors in the PVN.
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Objective Spinal cord injury-induced neuropathic pain(NP)does not respond well to any existing therapies clinically.This study aimed to explore the molecular metabolisms neuropathic pain by observing the expressions of the N -methyl-D-as-partic acid receptor 2B(NR2B),tumor necrosis factor-alpha(TNF-α)and brain-derived neurotrophic factor(BDNF)in different sta-ges of the condition in SD rats. Methods Thirty-six adult SD rats were randomly divided into a control,a sham operation and an NP model group.The NP model was established by spinal nerve ligation. At 5 and 14 days after modeling,the hindlimb motor function and paw withdrawal threshold(PWT)of the rats were evaluated by the open-field test and the expressions of NR 2B,TNF-αand BDNF in the dor-sal root ganglia of the L4-6 spinal cord were determined by Western blot. Results At 5 days after modeling,the open-field test showed a significantly shorter total distance of movement in the sham operation group than in the control([14 927.93 ±560.87]vs [18 225.15±371.76]mm,P<0.05)and even shorter in the NP model group([3 224.92±89.64]vs[18 225.15±371.76]mm, P<0.01).The time of activity was markedly decreased in the NP model group as compared with that in the control([203.48±19.94]vs [745.95±13.48]s,P<0.01),but with no statistically significant difference between the sham operation and control groups([727.93± 16.29]vs[745.95±13.48]s,P>0.05).At 14 days after modeling,both the total distance of movement and time of activity were re-markably shorter in the NP model than in the sham operation and control groups([3 395.53±96.12]vs[17 382.26±482.31]and [17 975.40±416.56]mm,P<0.01;[195.53±96.12]vs[739.31±18.36]and[775.20±16.84]s, P<0.01).The PWT showed no statistically significant difference among the three groups of rats before modeling(P>0.05)but markedly decreased in the NP model as compared with the sham operation and control groups(P<0.01),with no significant difference between the latter two(P>0.05).The expressions of NR2B,TNF-αand BDNF were remarkably up-regulated in the NP model group in comparison with the sham operation and control groups at 5 days after modeling(P>0.05)and even more significantly at 14 days(P<0.01). Conclusion NR2B and BDNF may be involved in the development and progression of neuropathic pain in rats.
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AIM:To observe the mechanism of Tianma Gouteng Decoction on the protein molecular level in the optic nerve crush model rats.METHODS:Totally 36 participants 36 male Wistar rats were divided randomly into six groups(6 in every group):normal control group,negative control group,Tianma Gouteng Decoction treatment groups (con-centrations were 0.6g/mL,1.2g/mL,2.4g/mL respictively) and ginkgo biloba tablets positive control group (concentrations was 1.2mg/mL).Nothing was done in the normal control group.The optic nerve of right eye in the other groups was done with the optic nerve crush model.Normal control group and negative control group was treated only with water.The average grey scale values of the N-methyl-D-aspartic acid receptor 2B (NMDA2B) receptor protein,beta-amyloid protein (Aβ) in the average grey scale values were detected.RESULTS:The average grey scale value of Tianma Gouteng Decoction in low,medium and high dose groups about NMDA2B receptor protein was significantly less than that of the negative control group (all P＜0.001),and there was no significant difference with the positive control group (P=0.092,0.411,0.676),the difference between normal control group and negative control group was significant (P＜0.001).The high dose group of betaamyloid's average grey scale value reduced significantly than the negative control group (P=0.030,0.001).The low dose group than the negative control group was not obviously (P=0.614).The high dose group was not significantly different from the positive control group (P=0.927),the difference between normal control group and negative control group was significant (P＜0.001).CONCLUSION:Tianma Gouteng Decoction can go through the decrease of the NMDA2B receptor protein expression and the control of beta-amyloid deposition to reduce the retinal ganglion cell injury and apoptosis.
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Liquiritigenin (LQ) is a flavonoid that can be isolated from Glycyrrhiza radix. It is frequently used as a tranditional oriental medicine herbal treatment for swelling and injury and for detoxification. However, the effects of LQ on cognitive function have not been fully explored. In this study, we evaluated the memory-enhancing effects of LQ and the underlying mechanisms with a focus on the N-methyl-D-aspartic acid receptor (NMDAR) in mice. Learning and memory ability were evaluated with the Y-maze and passive avoidance tests following administration of LQ. In addition, the expression of NMDAR subunits 1, 2A, and 2B; postsynaptic density-95 (PSD-95); phosphorylation of Ca2+/calmodulin-dependent protein kinase II (CaMKII); phosphorylation of extracellular signal-regulated kinase 1/2 (ERK 1/2); and phosphorylation of cAMP response element binding (CREB) proteins were examined by Western blot. In vivo, we found that treatment with LQ significantly improved memory performance in both behavioral tests. In vitro, LQ significantly increased NMDARs in the hippocampus. Furthermore, LQ significantly increased PSD-95 expression as well as CaMKII, ERK, and CREB phosphorylation in the hippocampus. Taken together, our results suggest that LQ has cognition enhancing activities and that these effects are mediated, in part, by activation of the NMDAR and CREB signaling pathways.
Subject(s)
Animals , Mice , Behavior Rating Scale , Blotting, Western , Calcium-Calmodulin-Dependent Protein Kinase Type 2 , Cognition , Glycyrrhiza , Hippocampus , In Vitro Techniques , Learning , Medicine, East Asian Traditional , Memory , N-Methylaspartate , Phosphorylation , Phosphotransferases , Protein Kinases , Receptors, N-Methyl-D-Aspartate , Response ElementsABSTRACT
Objective To investigate the effects of icariin, a major active component of traditional Chinese herb Epimedium on schizo-phrenia animal model. Methods MK-801, a N-methyl-D-aspartate (NMDA) receptor antagonist, was intraperitoneally injected into mice to establish a schizophrenia animal model. The open field behavior test infrared detection system was used to measure the mobility of mice in order to find the best optimal dose. 40 mice were randomly divided in to control group, model group, risperidone group and icariin group with 10 mice in each group. The risperidone group and the icariin group were given 0.1 mg/kg risperidone and 50 mg/kg icariin respectively. All groups were injected with 0.6 mg/kg MK-801 0.1 ml intraperitoneally, except the control group. The total distance and the central dis-tance within 210 minutes were tested. Results The total distance and the central distance were significantly longer in the model group than in the control group (P0.05). Conclusion Icariin may improve the positive and negative symptoms of schizophrenia mice, which may be beneficial to schizo-phrenia therapy.
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Objective To investigate the effect of cannabinoid receptor 1 ( CBR1 ) on spatial learning and memory function of neuropathic pain ( NP ) model rats and the expression of N-methyl-D-aspartic acid receptor 1(NR1) subunit in medial prefrontal cortex (mPFC).Methods Thirty-six healthy male Wistar rats were randomly divided into 4 groups, with 9 rats in each group: the sham operated group (SO group), the neuropathic pain model group (NP group), the NP model group with an mPFC injection of saline ( NS group ) , and the NP model group with an mPFC injection of the CBR 1 antagonist AM251 ( AM251 group).The NP model was prepared using the operation of chronic constriction injury ( CCI) of the right sciatic nerve.The mechanical withdrawal threshold ( MWT ) and the thermal withdrawal latency (TWL) of the rats in each group were detected at 3, 7, 14, 21 and 28 days after the operation.At 29 days after the operation , 18 rats of NP model were randomly selected and given an mPFC injection of saline or AM251 using a three-dimensional brain puncture.At days 30-37 after operation , the eight-arm maze test was performed to detect the spatial learning and memory function of the rats , and the rats were sacrificed immediately after this test.The expression levels of CBR1, NR1 and phosphorylated-N-methyl-D-aspartic acid receptor 1 ( p-NR1 ) ( Ser896 ) in the mPFC brain region were detected by Western blotting , RT-PCR and immunofluorescence.Results Compared with the SO group , the pain thresholds and the spatial learning and memory function of the rats in the NP group were significantly lower ( both P <0.05 ).Compared with the NS group , the rats in the AM251 group showed improvement about spatial learning and memory function ( P<0.05).Compared with the SO group ( the mRNA and protein level of CBR 1:0.23 ± 0.06,0.42 ±0.03), the mRNA(0.43 ±0.12) and protein (0.53 ±0.05) level of CBR1 in NP group increased (both P<0.05).Compared with the NS group (the mRNA and protein level of CBR1:0.42 ± 0.11,0.52 ±0.10), the mRNA (0.53 ±0.05) and protein (0.98 ±0.17) level of CBR1 in AM251 group increased (both P<0.05).Compared with the SO group (the mRNA and protein level of NR1 and the protein level of p-NR1:1.50 ±0.15,0.65 ±0.05,0.79 ±0.15), the mRNA (0.94 ±0.07) and protein (0.24 ±0.05) level of NR1 in NP group decreased (both P<0.05), the protein level of p-NR1 (0.33 ± 0.04) decreased (P<0.05).Compared with the NS group (the mRNA and protein level of NR1 and the protein level of p-NR1:1.09 ±0.14,0.26 ±0.06,0.31 ±0.08), the mRNA(1.58 ±0.10) and protein (1.42 ±0.10) level of NR1 in AM251 group increased (both P<0.05), the protein (0.95 ±0.15) level of p-NR1 increased ( P<0.05).Conclusion CBR1 can decrease the expression level of NR 1 and p-NR1 in the mPFC brain region of NP model rats and induce the spatial learning and memory impairment.
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Objective To observe the expression of cAMP -response element binding protein (CREB) and N-methyl-D-aspartic acid receptor (NMDA ) after intracochlear electrical stimulation in the auditory cortex and inferior colliculus in infant rats with auditory deprivation .Methods Sixty six SD infant rats were randomly divided into 6 groups (11 rats each group):4 weeks ,and 6 weeks after injection of ototoxic drug ,the control group ,and 3 weeks and 5 weeks after injection of ototoxic drug with intra -cochlear electrical stimulation for one week .Gentami-cin sulphate (350 mg/kg body weight) and frusemide (200 mg/kg body weight) were injected subcutaneously in the skin folds on the lateral abdominal side and the dorsal neck area ,respectively .The expression of CREB and NMDAR1protein were detected by immunohistological staining .Results The results of immunohisto -chemistry revealed that protein expression of CREB and NMDAR1 in 4 week group of injection increased as compared to the control group ,while decreasing as compared to intracochlear electrical stimulation group ,significantly .However ,protein expression of CREB and NMDAR1 in 6 week group of injection decreased as compared to the control group and in-tracochlear electrical stimulation group ,significantly .Conclusion Auditory deprivation could result in the expres-sion of protein of CREB and NMDAR1 in auditory cortex and inferior colliculus increasing in an early stage and then de-creasing in infant rats .Intracochlear electrical stimulation could result in the expression of proteins of CREB and NMDAR 1 in auditory cortex and inferior colliculus increasing in infant rats .The dynamic variation of CREB and NMDAR1 expression in rat auditory cortex and inferior colliculus reflects synaptic plasticity in neurons of auditory pathway .
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<p><b>OBJECTIVE</b>To explore the neuroprotective effects of baicalin against hypoxia and glucose deprivation-reperfusion (OGD/RO)-induced injury in SH-SY5Y cells.</p><p><b>METHODS</b>SH-SY5Y cells were divided into a control group, a OGD/RO group, which was subject to OGD/RO induction; and 3 baicalin groups subject to baicalin (1, 5, 25 μmol/L) for 2 h before induction of OGD/RO (low-, medium-, and high-dose baicalin groups). Cell viability was detected by thiazolyl blue tetrazolium bromide (MTT) assay and flow cytometric analysis was used to detect cell apoptosis. Real-time polymerase chain reaction was performed to determine the mRNA expression of caspase-3 gene. Western blot analysis was conducted to determine the expression of nuclear factor (NF)-κB and N-methyl-daspartic acid receptor-1 (NMDAR1).</p><p><b>RESULTS</b>Baicalin could significantly attenuate OGD/RO mediated apoptotic cell death in SH-SY5Y cells; the apoptosis rates in the low-, medium- and high-dose groups were 12.1%, 7.9%, and 5.4%, respectively. Western blot and real-time PCR analysis revealed that significant decrease in caspase-3 expression in the baicalin group compared with the OGD/RO group (P<0.01). Additionally, down-regulation of NF-κB and NMDAR1 was observed in the baicalin group compared with those obtained from the OGD/RO group. Compared with the low-dose baicalin group, remarkable decrease was noted in the medium- and high-dose groups (P<0.01).</p><p><b>CONCLUSION</b>Baicalin pre-treatment attenuates brain ischemia reperfusion injury by suppressing cellular apoptosis.</p>
Subject(s)
Humans , Apoptosis , Caspase 3 , Genetics , Metabolism , Cell Death , Cell Hypoxia , Cell Line, Tumor , Cell Survival , Flavonoids , Pharmacology , Glucose , Metabolism , NF-kappa B , Metabolism , Nerve Tissue Proteins , Metabolism , RNA, Messenger , Genetics , Metabolism , Real-Time Polymerase Chain Reaction , Receptors, N-Methyl-D-Aspartate , Metabolism , ReperfusionABSTRACT
The growing number of cognitive dysfunction patients is bringing heavy mental and financial burdens to the society and families.Voltage-gated potassium channels (Kv), which consist of delayed rectifier potassium channels and transient outward po -tassium channels , are involved in the incidence of cognitive dysfunction .This review summarized the role of Kv channels in cognitive dysfunction and their relationship with N-methyl-D-aspartic acid receptors ( NMDARs) that play an important role in the process of learning and memory .
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This work aims to study the pathogenesis of learning and memory impairment in offspring rats resulting from maternal enflurane anesthesia by focusing on the expression of the N-methyl-d-aspartic acid receptor subunit 2B (NR2B) in the hippocampus of the offspring. Thirty female Sprague-Dawley rats were randomly divided into three groups: control (C group), 4 h enflurane exposure (E1 group), and 8 h enflurane exposure (E2 group) groups. Eight to ten days after the initiation of pregnancy, rats from the E1 and E2 groups were allowed to inhale 1.7% enflurane in 2 L/min oxygen for 4 h and 8 h, respectively. Rats from the C group were allowed to inhale 2 L/min of oxygen only. The Morris water maze was used to assay the learning and memory function of the offspring on postnatal days 20 and 30. RT-PCR and immunohistochemistry assays were then used to measure the mRNA levels and protein expression of NR2B, respectively. Relative to offspring rats from the C group, those from the E1 and E2 groups exhibited longer escape latencies, lesser number of crossings over the platform, and less time spent in the target quadrant in the spatial exploration test (P < 0.05). In addition, the mRNA and protein expression levels of NR2B in the hippocampus of offspring rats in the E1 and E2 groups were down-regulated (P < 0.05). No significant differences between the E1 and E2 groups were observed (P > 0.05) in terms of mRNA levels and protein expression of NR2B. The cognitive function of the offspring is impaired when maternal rats are exposed to enflurane during early pregnancy. A possible mechanism of this effect is related to the down-regulation of NR2B expression.
Este trabalho objetiva o estudo da patogênese de deficiência no aprendizado e memória de prole de ratos resultante da anestesia maternal por enflurano, por meio da expressão da subunidade 2B do receptor do ácidoN-metil-D-aspártico (NR2B) no hipocampo dos filhotes. Dividiram-se, aleatoriamente, 30 fêmeas de ratos Sprague-Dawley em três grupos: controle (grupo C), exposição ao enflurano por 4 h (grupo E1) e por 8 h (grupo E2). De oito a 10 dias após o início da gravidez, os ratos dos grupos E1 e E2 inalaram enflurano 1,7% em 2 L/min de oxigênio, por 4 h e 8 h, respectivamente. Ratos do grupo C inalaram apenas 2 L/min de oxigênio. O labirinto de água de Morris foi empregado para analisar as funções de aprendizado e memória da cria em 20 e 30 dias após o nascimento. Utilizaram-se ensaios de RT-PCR e de imuno-histoquímica para medir os níveis de mRNA e expressão da proteína do NR2B, respectivamente. Em comparação com os ratos controle do grupo C, aqueles dos grupos E1 e E2 exibiram latências de escape mais longas, menor número de travessias na plataforma e menos tempo gasto no quadrante alvo no teste de exploração espacial (P < 0,05). Adicionalmente, os níveis de expressão de mRNA e de proteína do NR2B no hipocampo dos filhotes nos grupos E1 e E2 estavam reduzidos (P < 0,05). Não se observaram diferenças significativas entre os grupos E1 e E2 (P < 0,05) quanto aos níveis de mRNA e à expressão de proteína de NR2B. A função cognitiva dos filhotes é prejudicada quando as mães são expostas ao enflurano durante o início da gravidez. O mecanismo possível para esse efeito está relacionado à diminuição na expressão de NR2B.
Subject(s)
Rats , Pregnancy , Maternal Exposure/classification , Enflurane/analysis , Gene Expression/immunology , N-Methylaspartate/analysis , AnesthesiaABSTRACT
Objective To investigate the roles of spinal N-methyl-D-aspartic acid receptor-extracellular signal-regulated protein kinases 5 signaling pathway in naloxone-induced withdrawal response in morphine-dependent rats.Methods Ninety-six adult male SD rats weighting 230-250 g were randomly divided into 4 groups:control group,withdrawal group,DMSO group and MK801 group.Rats were subcutaneously injected with morphine.On day 6,rats were injected with naloxone (intraperitoneal) to precipitate morphine withdrawal syndromes.To identify the function of NMDAR-ERK5 signaling pathway in morphine withdrawal,morphine withdrawal-like behavior test and western blot technique were used in this research.The scores of morphine withdrawal symptom,morphine withdrawal-induced allodynia and the activation of ERK5 in spinal cord were observed after intrathecal injection of MK801.Results There was no withdrawal symptoms and withdrawal-induced allodynia in group A after intraperitoneal injection of naloxone.Compared with group A,withdrawal score (45.2±7.3),score of withdrawal-induced allodynia (14.4±3.7) of group B,withdrawal score (44.7±6.2),score of withdrawal-induced allodynia (13.2±2.7) of group C and withdrawal score (28.3±1.6),score of withdrawal-induced allodynia (5.9± 1.1) of group D were significantly increased (P＜ 0.05).Compared with group C,the total withdrawal score (28.3 ± 1.6),score of withdrawal-induced allodynia (5.9± 1.1) of group D were significantly decreased (P＜0.05).Compared with group A,the expression of spinal p-ERK5 of group B (12848±621) and group C (12579±396) were significantly increased (P＜0.05).Compared with group C,the expression of spinal p-ERK5 of group D (5 123±546) was significantly decreased (P＜0.05).Condusion The signaling pathway of spinal N-methyl-D-aspartic acid receptor-extracellular signal-regulated protein kinases 5 contributes to naloxone-induced withdrawal response in morphine-dependent rats.
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<p><b>OBJECTIVE</b>To study the effect of chronic noise exposure on expression of N-methyl-D-aspartic acid receptor 2B (NR2B) and tau phosphorylation in hippocampus of rats.</p><p><b>METHODS</b>Twenty-four male SD rats were divided in control group and chronic noise exposure group. NR2B expression and tau phosphorylation in hippocampus of rats were detected after chronic noise exposure (100 dB SPL white noise, 4 h/d×30d) and their mechanisms underlying neuronal apoptosis in hippocampus of rats with TUNEL staining.</p><p><b>RESULTS</b>The NR2B expression decreased significantly after chronic noise exposure which resulted in tau hyperphosphorylation and neural apoptosis in hippocampus of rats. Immunohistochemistry showed that the tau hyperphosphorylation was most prominent in dentate gyrus (DG) and CA1 region of rat hippocampus.</p><p><b>CONCLUSION</b>The abnormality of neurotransmitter system, especially Glu and NR2B containing NMDA receptor, and tau hyperphosphorylation in hippocampus of rats, may play a role in chronic noise-induced neural apoptosis and cognition impairment.</p>
Subject(s)
Animals , Male , Rats , Apoptosis , Hippocampus , Cell Biology , Metabolism , Neurons , Cell Biology , Metabolism , Noise , Phosphorylation , Rats, Sprague-Dawley , Receptors, N-Methyl-D-Aspartate , Metabolism , tau Proteins , MetabolismABSTRACT
Ginsenosides are low molecular weight glycosides found in ginseng that exhibit neuroprotective effects through inhibition of N-methyl-D-aspartic acid (NMDA) receptor channel activity. Ginsenosides, like other natural compounds, are metabolized by gastric juices and intestinal microorganisms to produce ginsenoside metabolites. However, little is known about how ginsenoside metabolites regulate NMDA receptor channel activity. In the present study, we investigated the effects of ginsenoside metabolites, such as compound K (CK), protopanaxadiol (PPD), and protopanaxatriol (PPT), on oocytes that heterologously express the rat NMDA receptor. NMDA receptor-mediated ion current (INMDA) was measured using the 2-electrode voltage clamp technique. In oocytes injected with cRNAs encoding NMDA receptor subunits, PPT, but not CK or PPD, reversibly inhibited INMDA in a concentration-dependent manner. The IC50 for PPT on INMDA was 48.1+/-4.6 microM, was non-competitive with NMDA, and was independent of the membrane holding potential. These results demonstrate the possibility that PPT interacts with the NMDA receptor, although not at the NMDA binding site, and that the inhibitory effects of PPT on INMDA could be related to ginseng-mediated neuroprotection.
Subject(s)
Animals , Rats , Binding Sites , Gastric Juice , Ginsenosides , Glycosides , Inhibitory Concentration 50 , Membranes , Molecular Weight , N-Methylaspartate , Neuroprotective Agents , Oocytes , Panax , RNA, Complementary , Sapogenins , TuberculinABSTRACT
Objective To investigate the influence of Memantine on changes of N-methyl-D-aspartic acid receptor 2B (NMDAR-2B) level, the expression of postsynaptic density 95 ( PSD-95) and calcium/calmodulin-dependent protein kinase Ⅱ (CaMK Ⅱ)activities in the hippocampus of vascular dementia(VD)rats and their recognition. Methods The VD rat model was established by permanent,bilateral occlusion of the common carotid arteries. One hundred and forty-four Wistar rats were randomly divided into sham-operated group, VD model group and Memantine-treated group. The water maze test was performed to detect the ability of learning and memory of the rats,the changes of NMDAR-2B level were measured by RT-PCR,the changes in the expression of PSD-95 were detected by immunohistochemical staining,and the changes in the CaMK Ⅱ activities were determined by incorporation of ~(32)P into histone. Results Compared with the sham-operated group, the ability of learning and memory of VD rats was decreased significantly(P<0. 01); the level of NMDAR-2B and the expression of PSD-95 increased significantly at the 4th week after operation(F<0. 05 or 0. 01)and decreased at the 8th to 16th week after operation (P<0. 01). Total CaMK Ⅱ activity was increased significantly at the 4th week after operation(P<0. 01) ,then dropped at the 8th week after operation(P>0. 05) ,and decreased significantly at the 12th,16th week after operation(P<0. 01). As for Memantine-treated group,at the 4th week after operation,there was no statistically significant difference in the parameters mentioned above in contrast with the sham-operated group. At the 8th,and 12th week after operation,the ability of learning and memory,the level of NMDAR-2B and the expression of PSD-95 were significantly increased as compared with VD rats(P<0. 01 or 0. 05) ,but total CaMK Ⅱ activity was similar to that of VD rats. Conclusion With the development of VD,NMDAR-2B level,the expression of PSD-95 and CaMK Ⅱ activities were firstly over-activated,and then decreased greatly. Memantine can improve VD rats' recognition by modulating the expression of NMDAR-2B,but its effect on CaMK Ⅱactivity was limited.
ABSTRACT
Objective To investigate changes of N-methyl-D-aspartic acid receptor 2B(NR2B) level and calcium/calmodulin-dependent protein kinase Ⅱ(CaMK Ⅱ) activities in the hippocampus of vascular dementia(VD) rats and the intervention effects of Memantine.Methods The VD rat models were established by permanent,bilateral occlusion of the common carotid arteries.The rats were randomly divided into VD group and Memantine-treated group.At 4,8,12,16 weeks after operation,the water maze test was performed to detect the ability of learning and memory of the rats.The changes of NR2B level were measured by RT-PCR.The changes of the CaMK Ⅱ activities were determined by incorporation of 32P into histone.The resoults were compared with the sham-operated group.Results Compared with the sham-operated group,the ability of learning and memory of VD group rats at each time point after operation decreased significantly(all P