Role of Cannabinoid CB1 Receptor in Object Recognition Memory Impairment in Chronically Rapid Eye Movement Sleep-deprived Rats

Objective We aimed to investigate whether antagonism of the cannabinoid CB1 receptor(CB1R)could affect novel object recognition(NOR)memory in chronically rapid eye movement sleep-deprived(RSD)rats.Methods The animals were examined for recognition memory following a 7-day chronic partial RSD paradigm using the multiple platform technique.The CB1R antagonist rimonabant(1 or 3 mg/kg,i.p.)was administered either at one hour prior to the sample phase for acquisition,or immediately after the sample phase for consolidation,or at one hour before the test phase for retrieval of NOR memory.For the reconsolidation task,rimonabant was administered immediately after the second sample phase.Results The RSD episode impaired acquisition,consolidation,and retrieval,but it did not affect the reconsolidation of NOR memory.Rimonabant administration did not affect acquisition,consolidation,and reconsolidation;however,it attenuated impairment of the retrieval of NOR memory induced by chronic RSD.Conclusions These findings,along with our previous report,would seem to suggest that RSD may affect different phases of recognition memory based on its duration.Importantly,it seems that the CB1R may,at least in part,be involved in the adverse effects of chronic RSD on the retrieval,but not in the acquisition,consolidation,and reconsolidation,of NOR memory.

Local Peripheral Effects of <i>β</i>-Caryophyllene through CB₂Receptors in Neuropathic Pain in Mice

β-Caryophyllene (BCP) is known as a common constitute of the essential oils of numerous food plants and primary component in Cannabis. In this study, we investigated the effect of local intraplantar (i.pl.) injection of BCP on mechanical hypersensitivity induced by partial sciatic nerve ligation (PSNL) in mice. Relative to sham operation controls, mice with the PSNL displayed a maximum level of hyperresponsiveness to von Frey metallic filament on post-operative day 7. PSNL-induced allodynia was seen in the ipsilateral side of nerve ligation, but not in the contralateral side. The i.pl. injection of BCP into the ipsilateral hindpaw to PSNL attenuated mechanical allodynia in a dose-dependent manner. BCP injection into the contralateral hindpaw did not produce anti-allodynic effects, suggesting a local peripheral anti-allodynic effect of BCP. Anti-allodynic effects induced by i.pl. injection of BCP were prevented by pretreatment with the cannabinoid (CB2) receptor antagonist AM630, but not by the CB1 receptor antagonist AM251. These data suggest that i.pl. injection of BCP could produce anti-allodynia by activating peripheral CB2 receptors, but not CB1 receptors in a mouse model of neuropathic pain. Taken together, these results suggest that peripheral CB2 receptors may contribute to the effectiveness of BCP in the treatment of neuropathic pain disorders.

Cannabinoid CB_(2) receptors and spinal microglia are implicated in tingenone-mediated antinociception in mice

Objective:To investigate the antinociceptive effect of tingenone on inflammatory pain,as well as and the involvement of the cannabinoid receptors type 2(CB2)and spinal microglia in this process.Methods:Male Swiss mice were subjected to inflammatory pain induced by intraplantar injection of carrageenan.The nociceptive threshold was measured by von Frey filaments test.Tingenone was administered orally 60 min before carrageenan injection.To evaluate the involvement of CB2 receptor,endocannabinoids,and microglia,AM630(a CB2 receptor antagonist),MAFP(an inhibitor of an enzyme that hydrolyses endocannabinoids),and minocycline(a microglial inhibitor)were given intrathecally 20 min before tingenone administration.In addition,an immunofluorescence assay was used to evaluate CB2 receptor and CD11 B(a microglial marker)expression in the spinal cord dorsal horn.Results:Tingenone significantly reduced carrageenan-induced hyperalgesia,which was reversed by pretreatment with AM630.MAFP and minocycline potentiated and prolonged the tingenoneinduced antinociception.CD11 B expression was increased in the spinal cord dorsal horn of mice with inflammatory pain pretreated with tingenone,which was reduced by AM630,MAFP,and minocycline.Conclusions:CB2 receptors and endocannabinoids participate in the tingenone-induced antinociception which may involve the inhibition of microglia at spinal level.

Novel Method for Synthesis of Diarylpyrazole Derivatives as Cannabinoid CB_1 Receptor Antagonists

A novel and efficient method was developed for the synthesis of diarylpyrazole derivatives as cannabinoid CB1 receptor antagonist via four step reactions. The key step was the synthesis of a diarylpyrazole skeleton, which involved initial condensation of the sodium salt of compound 12 with diazonium compounds, and further cyclization by heating at reflux in acetic acid. Eight diarylpyrazole derivatives and nine new synthesized compounds were characterized by 1H NMR, IR, MS, and elemental analysis. The reaction conditions were mild and the overall yields of the target compounds ranged from 26% to 44%.

Activation of cannabinoid receptor CB2 regulates LPS-induced pro-inflammatory cytokine production and osteoclastogenic gene expression in human periodontal ligament cells

Background and Objective: It has been found that human periodontal ligament (hPDL) cells express cannabinoid receptor CB2. However, the functional importance of CB2 in hPDL cells exposed to bacterial endotoxins is not known. Here we investigate if the inflammation promoter lipopolysaccharide (LPS) affects CB2 expression and if activation of CB2 regulates LPS-induced pro-inflammatory cytokine production and osteoclastogenic gene expression in hPDL cells. Methods: The hPDL cells were obtained from extracted teeth of periodontally healthy subjects. CB2 expression in hPDL cells exposed to LPS was deter- mined by quantitative real-time PCR analysis. Then, the cells were incubated with or without CB2-specific agonist HU-308 before further stimulation with LPS. In some experiments, the cells were pre-treated with CB2-specific antagonist SR144528. The production of pro-inflammatory cytokines interleukin-1 beta (IL- 1β), interleukin-6 (IL-6) and tumor necrosis factoralpha (TNF-α) was assessed by enzyme-linked immunosorbent assay (ELISA). The mRNA expression of osteoclastogenic genes osteoprotegerin (OPG) and receptor activator of NF-κB ligand (RANKL) was examined using quantitative real-time PCR analysis. Results: CB2 expression in hPDL cells was markedly enhanced by LPS. HU-308 significantly suppressed the production of IL-1β, IL-6 and TNF-α exposed to LPS, whereas SR144528 attenuated this effect. The OPG/RANKL ratio decreased when exposed to LPS, furthermore increased significantly with the addition of HU-308 and finally decreased markedly after pretreatment with SR144528. Conclusion: Our study demonstrated that activation of CB2 had anti-inflammatory and anti-resorptive effects on LPS-stimulated hPDL cells. These findings suggest that activation of CB2 might be an effective therapeutic strategy for the treatment of inflammation and alveolar bone resorption in periodontitis.

Distribution and Possible Function of Cannabinoid Receptor Subtype 1 in the Human Prostate

Background: Cannabinoid receptor subtype 1 (CB1) has a relationship to the proliferation of various cells including malignant tumoral cells. We investigated and compared the expression of CB1 in benign and malignant human prostate tissues and in benign and malignant human prostate cell lines, as well as its function for the proliferation of human prostate cancer cells. Methods: Real-time quantitative PCR was performed to compare its expressions in human prostate tissues (normal, benign hyperplasia, and cancer) and prostate cell lines (3 normal and 3 malignant). For localization of CB1, immunofluorescent staining with rabbit anti-CB1 polyclonal antibodies and tetramethyl isothiocyanate (TRITC)-labeled swine anti-rabbit immunoglobulin (DAKO) were used under fluorescence microscope. To further analyze whether cell death was induced by anandamide (non-selective agonist for CB1/CB2) via a receptor dependent mechanism, the viability of DU145 cells, which is known as androgen-insensitive prostate cancer cell, was measured using MTT assay. Results: CB1mRNA was found to be expressed in the all 3 human prostate tissues, however, CB1 protein was expressed in BPH and low grade malignant PC tissues, but not in high grade malignant PC tissues. CB1 as for cell lines, the expression of CB1 was low in malignant cell lines except for DU145. Anandamide elicited cell death, which was significantly inhibited by AM251 (selective antagonist for CB1), indicating that cell death induced by anandamide in DU145 cells was mediated by CB1. Anandamide time-dependently elicits up-regulation of CB1 in DU145 cells. Conclusions: CB1 may be an inhibitory regulator of androgen-insensitive human prostate cancer epithelial cell growth.

Pharmacological characterizationof synthetic cannabinoid MAM-2201：radioligand binding and abuse-related effects

OBJECTIVE Over 30% of all new psychoactive substances identified by the UN Office on Drugs and Crime in 2016 were synthetic cannabinoids.The recent emergence of MAM-2201 on the illicit market is troubling because this drug has no precedent in either the scientific or patent literature,and appears to be a novel compound developed specifically as a "graymarket" drug of abuse bystructurally combining the known synthetic cannabinoids JWH-122 and AM-2201.There is currently no published information regarding the pharmacology of MAM-2201.METHODS The present studies characterized cannabinoid-like effects of MAM-2201 in vitro(interactions with cannabinoid type 1 receptors[CB1 Rs]) and in vivo(in mice and rats).RESULTS In a radioligand binding assay using [3 H]CP55,940 in HEK cell membranes transfected with the CB1 R,MAM-2201(K i=5.4 nmol·L^(-1)),had higher binding affinity than WIN 55,212-2(K i=80 nmol·L^(-1)),and D9-THC(K i=8.3 nmol·L^(-1)).The E max values for MAM-2201 and WIN 55,212-2 in an assay of agonist inhibition of forskolin-stimulated c AMP were 85%(EC50=0.45 nmol·L^(-1)) and 95%,respectively,as compared with the D9-THC E max of 74%.In mice,MAM-2201(0.003-1.0 mg·kg^(-1),IP) produced dose-dependent cannabimimetic effects which were both more potent and more effective than those of D9-THC.MAM-2201 and D9-THC dose-dependently produced hypothermia:ED50=0.287 and 25.4 mg·kg^(-1),analgesia:ED50=0.125 and 29.4 mg·kg^(-1),and catalepsy:ED50=0.301 and18.9 mg·kg^(-1) in adult male CD1 mice.Importantly,MAM-2201 also elicited convulsant effects at a dose of 1.0 mg·kg^(-1) in 8/8 murine subjects.In rats,MAM-2201 produced dose-dependent D9-THC-like interoceptive effects in subjects trained to discriminate 3.0 mg·kg^(-1)(IP) D9-THC from saline.CONCLUSION MAM-2201 binds CB1 Rs with high affinity and agonist efficacy,and functions as a potent cannabinoid agonist in vivo across several complementary measures of cannabinoid activity in two rodent species.

AB059.Expression patterns of CB1R,NAPE-PLD,and FAAH in the primary visual cortex of vervet monkeys

Background:The expression,localization,and function of the endocannabinoid system has been well characterized in recent years in the monkey retina and in the primary thalamic relay,the lateral geniculate nucleus(dLGN).Few data are available on cortical recipients’structures of the dLGN,namely the primary visual cortex(V1).The goal of this study is to characterize the expression and localization of the metabotropic cannabinoid receptor type 1(CB1R),the synthesizing enzyme N-acyl phosphatidyl-ethanolamine phospholipase D(NAPE-PLD),and the degradation enzyme fatty acid amide hydrolase(FAAH)in the vervet monkey area V1.Methods:Using Western blots and immunohistochemistry,we investigated the expression patterns of CB1R,NAPE-PLD,and FAAH in the vervet monkey primary visual cortex.Results:CB1R,NAPE-PLD,and FAAH were expressed in the primary visual cortex throughout the rostro-caudal axis.CB1R showed very low levels of staining in cortical layer 4,with higher expressions in all other cortical layers,especially layer 1.NAPE-PLD and FAAH expressions were highest in layers 1,2 and 3,and lowest in layer 4.Conclusions:Interestingly enough,CB1R was very low in layer 4 of V1 in comparison to the other cortical layers.The visual information coming from the dLGN and entering layer 4Calpha(magno cells)and 4Cbeta(parvo cells)may be therefore modulated by the higher expression levels of CB1R in cortical layers 2 and 3 on the way to the dorsal and ventral visual streams.This is further supported by the higher expression of NAPE-PLD and FAAH in the outer cortical layers.These data indicate that CB1R system can influence the network of activity patterns in the visual stream after the visual information has reached area V1.These novel results provide insights for understanding the role of the endocannabinoids in the modulation of cortical visual inputs,and hence,visual perception.

AB007. Expression and localization of CB1R,NAPE-PLD,and FAAH in the primary visual cortex of vervet monkeys

Background:The goal of this study is to determine the expression and localization of the cannabinoid receptor type 1(CB1R),the synthesizing enzyme N-acyl phosphatidyl-ethanolamine phospholipase D(NAPE-PLD),and the degradation enzyme fatty acid amide hydrolase(FAAH)in the vervet monkey area V1 to better understand the mechanisms underlying the effects of eCB system modulation on cortical visual processing.Methods:Using Western blots and immunohistochemistry,we investigated the laminar and cellular expression patterns of CB1R,NAPE-PLD,and FAAH across the rostrocaudal axis of the vervet monkey(Chlorocebus sabaeus)primary visual cortex.Results:CB1R,NAPE-PLD,and FAAH were expressed in V1 throughout the rostrocaudal axis.CB1R showed very low staining in layer(L)4,with higher expression in all other layers,especially L1,followed by L2 and L3.NAPE-PLD and FAAH expression patterns were similar,but not quite as low in L4.CB1R,NAPE-PLD,and FAAH were localized in vGlut2-positive cells,representing glutamatergic projection neurons,and in somatostatin(SST)-positive cells,a class of GABAergic interneurons.Conclusions:The low level of CB1R in L4 indicates less direct endocannabinoid modulation of V1 afferents from the dLGN,but that greater modulation may occur via the higher expression of CB1R in L2 and L3 on the way to the dorsal and ventral visual streams.This is further supported by the higher expression of NAPE-PLD and FAAH in these layers.Expression in vGlut2-positive and SST-positive cells represents a role at both glutamatergic and GABAergic neurons.These data indicate that CB1R may influence the network of activity patterns in the visual streams after the visual information has reached V1,and thus may influence visual perception.

CB 1 cannabinoid receptor participates in the vascular hyporeactivity resulting from hemorrhagic shock in rats

Background Vascular hyporeactivity, which occurs in the terminal stage of hemorrhagic shock, is believed to be critical for treating hemorrhagic shock. The present study was designed to examine whether the CB1 cannabinoid receptor （CB1 R） was involved in the development of vascular hyporeactivity in rats suffering from hemorrhagic shock. Methods Sixteen animals were randomly divided into two groups （n=8 in each group）： sham-operated （Sham） and hemorrhagic shock （HS） groups. Hemorrhagic shock was induced by bleeding. The mean arterial pressure （MAP） was reduced to and stabilized at （25±5） mmHg for 2 hours. The vascular reactivity was determined by the response of MAP to norepinephrine （NE）. In later experiments another twelve animals were used in which the changes of CB1R mRNA and protein in aorta and superior mesenteric artery （SMA） were analyzed by RT-PCR and Western blotting. In addition, we investigated the effects of a CB1R antagonist on the vascular hyporeactivity and survival rates in rats with hemorrhagic shock. Survival rates were analyzed by the Fisher＇s exact probability test. The MAP response was analyzed by one-way analysis of variance （ANOVA）. Results Vascular hyporeactivity developed in all animals suffering from hemorrhagic shock. The expression of CBIR mRNA and protein in aorta and 2-3 branches of the SMA were significantly increased in the HS group after the development of vascular hyporeactivity when compared to those in Sham group. When SR141716A or AM251 was administered, the MAP response to NE was （41.75±4.08） mmHg or （44.78±1.80） mmHg respectively, which was higher than that in saline groups with （4.31±0.36） mmHg （P 〈0.01）. We also showed an increased 4-hour survival rate in the SR141716A or AM251-treated group with 20% or 30%, but with a statistically significant difference present between the AM251-treated and saline groups （P 〈0.05）. Conclusions CBIR is involved in vascular hyporeactivity resulting from hemorrhagic shock in rats, and CB1R antagonist may be useful in treating patients with traumatic, hemorrhagic shock who need field-rescue or initial treatment.

利莫那班对肝纤维化C57小鼠肝组织大麻素受体1及α-SMA表达的影响

目的研究大麻素受体1(CB1)拮抗剂利莫那班对肝纤维化模型C57小鼠肝组织中CB1、α-平滑肌肌动蛋白(α-SMA)表达的影响,及其抗肝纤维化的作用机制。方法 30只C57小鼠随机分为3组,分别为正常对照组、模型对照组及利莫那班组,每组10只。采用四氯化碳腹腔注射诱导形成小鼠肝纤维化模型。造模2周后于继续造模同时,正常对照组和模型对照组每天生理盐水灌胃,利莫那班组用利莫那班灌胃。第8周造模结束时处死小鼠,留取肝脏组织标本,分别进行HE和Masson三色染色,应用免疫组织化学方法检测肝组织中CB1和α-SMA的表达,并进行肝组织纤维化评分(S评分)。结果模型对照组和利莫那班组肝组织S评分、CB1和α-SMA阳性表达量均高于正常对照组(均P<0.05),利莫那班组均低于模型对照组(均P<0.05);正常对照组、模型对照组和利莫那班组CB1评分、α-SMA评分与S评分相互之间均呈正相关(均P<0.05)。结论肝组织CB1的激活可促进肝纤维化的形成,CB1拮抗剂利莫那班通过抑制CB1表达,进而抑制肝星状细胞的增殖和激活,从而起到抗肝纤维化的作用。

大麻素系统与胃肠道内脏痛调控关系的研究进展

腹痛是功能性胃肠病(FGIDs),特别是肠易激综合征(IBS)的主要症状之一,严重影响患者的生活质量。然而,其病理生理学机制复杂且仍未明确。大麻素已被应用于疼痛机制的研究和临床治疗,但成瘾性等中枢系统不良反应限制了其应用。因此,研究大麻素系统的外周作用途径,对提高大麻素治疗慢性疼痛(特别是内脏痛)的效果,具有重要意义。本文就大麻素系统与胃肠道内脏痛调控关系的研究进展作一综述。

补阳还五汤对大鼠化疗相关外周神经痛的预防作用及其机制

目的观察补阳还五汤对紫杉醇诱导的大鼠外周神经痛的预防作用,并以脊髓大麻素受体为主要靶点,探讨其作用机制。方法将50只SD大鼠随机分为对照组、模型组、预防组、AM630组、AM251组,每组10只。除对照组外,其余各组于实验第1,3,5,7天分别腹腔注射紫杉醇2 mg/kg;预防组在建模的同时每天予补阳还五汤2.5 g/(kg·d)灌胃干预14 d;AM630组在预防组的基础上于每天灌胃前予3 mg/kg大麻素Ⅱ型受体(CBR2)阻滞剂AM630腹腔注射;AM251组在预防组的基础上于每天灌胃前予1.5 mg/kg大麻素Ⅰ型受体(CBR1)阻滞剂AM251腹腔注射。每7 d记录1次各组大鼠体质量,并使用von fery纤维丝测试各组大鼠机械缩足阈值(MWT),共观察28 d;实验观察28 d后使用RT-PCR检测各组大鼠脊髓组织中CBR1、CBR2、胶质纤维酸性蛋白(GFAP)、白细胞介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)的mRNA表达水平。结果实验第7,14,21,28天,各组大鼠体质量增量比较差异均无统计学意义(P均>0.05)。模型组实验第7,14,21,28天的MWT均显著低于同期对照组(P均<0.05);预防组、AM251组实验第14,21,28天的MWT均显著高于同期模型组(P均<0.05),但AM630组与模型组比较、预防组与AM251组比较差异均无统计学意义(P均>0.05)。模型组CBR2、CBR1、GFAP mRNA表达水平与对照组比较差异均无统计学意义(P均>0.05),IL-1β、TNF-αmRNA表达水平明显高于对照组(P均<0.05);预防组和AM251组CBR2 mRNA表达水平明显高于模型组(P均<0.05),IL-1β、TNF-αmRNA表达水平均明显低于模型组(P均<0.05);AM630组与模型组比较、预防组与AM251组比较各相关蛋白mRNA表达水平差异均无统计学意义(P均>0.05)。结论补阳还五汤可以预防紫杉醇诱导的外周神经痛,机制可能与其激活脊髓CBR2,并进一步抑制脊髓IL-1β、TNF-α等炎症细胞因子的表达有关。

外周型Ⅰ型大麻素受体选择性拮抗剂的研究进展

Ⅰ型大麻素受体(cannabinoid 1 receptor,CB1R)是肥胖症治疗药物研发的最重要靶标之一,然而以利莫那班为代表的CB1R拮抗剂因中枢作用产生的副作用限制了其临床应用。不透过血脑屏障的外周型CB1R选择性拮抗剂在保留第1代CB1R拮抗剂减肥效应的同时,避免了其中枢相关的副作用,成为当前CB1R拮抗剂类新型减肥药物研发的方向。本文综述了外周型CB1R选择性拮抗剂的研究进展。

大麻素受体1介导人类中性粒细胞dHL60的迁移功能

目的研究大麻素受体(cannabinoid receptors,CBs)对人类中性粒细胞(d HL60)迁移的影响。方法体外培养人早幼粒白血病细胞系HL60,使用二甲基亚砜(dimethylsulphoxide,DMSO)诱导为类中性粒细胞(d HL60),运用实时荧光定量聚合酶链反应检测其分化标志物CD11b mRNA的表达;应用琼脂糖凝胶电泳、Western blotting法及免疫荧光技术检测其大麻素受体1(CB1)及受体2(CB2)的表达;ACEA、AM281分别为CB1的药理学激动剂和拮抗剂,JWH133、AM630分别为CB2的药理学激动剂和拮抗剂,应用Boyden chamber法检测ACEA和JWH133对d HL60迁移的影响,并从药理学阻断CB1、CB2后,检测其迁移功能的变化;使用鬼笔环肽染细胞肌动蛋白纤维,并应用高内涵扫描分析的方法对肌动蛋白纤维的聚合进行分析。结果 d HL60在mRNA和蛋白质水平上均表达CB1、CB2;ACEA能够诱导d HL60的迁移及其细胞骨架的聚合,且其所诱导的迁移能够被CB1的药理学阻断剂AM281所阻断,而CB2的药理学阻断剂AM630对ACEA所诱导的迁移并无影响;给予CB2的激动剂JWH133对d HL60的迁移及细胞骨架的聚合无明显作用。结论激活CB1能够促进d HL60的迁移。

大麻素受体2激动剂在谷氨酸氧化应激损伤中保护作用实验研究

目的:评价大麻素受体2(CB 2受体)通过抗氧化应激机制在谷氨酸对共培养小胶质细胞和神经元损伤中的保护作用。方法:采用随机数字表法将培养的N9小胶质细胞和HT22神经元分为四组(n=24):对照组(Con组)、谷氨酸组(Glu组)、CB 2受体激动剂AM1241+谷氨酸组(AM1241+Glu组)和AM1241+CB 2受体拮抗剂AM630+谷氨酸组(AM1241+AM630+Glu组)。Con组正常培养24 h;Glu组用含10 mmol/L谷氨酸的培养基孵育24 h;AM1241+Glu组用含2μmol/L AM1241和10 mmol/L谷氨酸的培养基孵育24 h;AM1241+AM630+Glu组含2μmol/L AM1241、6μmol/L AM630及10 mmol/L谷氨酸的培养基孵育24 h。采用MTT法测定细胞活力,采用化学比色法测定乳酸脱氢酶(LDH)、超氧化物歧化酶(SOD)活性及丙二醛(MDA)的含量。结果:与Con组比较,Glu组和AM1241+AM630+Glu组细胞活力和SOD活性降低,LDH活性和MDA含量升高(均P<0.05),AM1241+Glu组细胞活力和SOD活性降低,LDH含量升高(均P<0.05);与Glu组比较,AM1241+Glu组细胞活力和SOD活性升高,LDH活性和MDA含量降低(均P<0.05);与AM1241+Glu组比较,AM1241+AM630+Glu组细胞活力和SOD活性降低,LDH活性和MDA含量升高(均P<0.05)。结论:CB 2受体激活减轻谷氨酸诱发小胶质细胞和神经元损伤的机制与抗氧化作用有关。

Anandamide Depresses Glycinergic and GABAergic Inhibitory Transmissions in Adult Rat Substantia Gelatinosa Neurons

Cannabinoid CB1 receptors have been found in the superficial dorsal horn of the spinal cord, particularly the substantia gelatinosa (SG), which is thought to play a pivotal role in modulating nociceptive transmission. Although cannabinoids are known to inhibit excitatory transmission in SG neurons, their effects on inhibitory transmission have not yet been examined fully. In order to know further about a role of cannabinoids in regulating nociceptive transmission, we examined the effects of cannabinoids on inhibitory transmissions in adult rat SG neurons using whole-cell voltage-clamp recordings. Anandamide (10 μM) superfused for 2 min reduced glycinergic and GABAergic electrically-evoked inhibitory postsynaptic current (IPSC) amplitudes;these actions persisted for more than 6 min after washout. Similar actions were produced by cannabinoid-receptor agonist WIN55,212-2 (5 μM) and 2-arachidonoyl glycerol (20 μM). The evoked IPSC amplitudes reduced by anandamide recovered to the control level following superfusion of CB1-receptor antagonist SR141716A (5 μM). A ratio of the second to first evoked IPSC amplitude in paired-pulse experiments was increased by anandamide (10 μM). The frequencies of glycinergic and GABAergic spontaneous IPSCs were reduced by anandamide (10 μM) without a change in their amplitudes. It is concluded that cannabinoids depress inhibitory transmissions in adult rat SG neurons by activating CB1 receptors in nerve terminals. This action could contribute to the modulation of nociceptive transmission by cannabinoids.

大麻素CB1受体对大鼠视网膜神经节细胞诱发动作电位的作用(英文)

激活大麻素CB1受体(CB1Rs)通过调控多种离子通道,从而调节脊椎动物视网膜的功能。本文旨在利用膜片钳全细胞记录技术,在大鼠视网膜薄片上研究CB1Rs对神经节细胞兴奋性的作用。结果显示,在电流钳制状态下,灌流CB1R激动剂WIN55212-2(WIN,5μmol/L)对神经节细胞的自发动作电位发放频率和静息膜电位均没有显著影响。在灌流液中加入CNQX,D-APV,bicuculline和strychnine以阻断神经节细胞的兴奋性和抑制性输入,灌流5μmol/L WIN对正向电流注入(+10pA到+100pA)诱发的动作电位的频率也没有显著影响。位相分析结果显示,触发动作电位的阈值电位和触发第一个动作电位的延迟时间在加入WIN前后也没有显著改变;然而,WIN显著降低动作电位的上升和下降相速率(±dV/dtmax),而且该作用可被CB1R拮抗剂SR141716所阻断。此外,在阻断突触输入的情况下,WIN对神经节细胞的膜电位也没有显著影响。以上结果提示,激活大麻素CB1Rs通过调控诱发动作电位,从而调节大鼠视网膜神经节细胞的兴奋性。

ACEA改善线粒体复合体活性诱导神经保护作用研究

目的:探讨线粒体复合体活性对大麻素CB1受体选择性激动剂ACEA神经保护作用的影响。方法:将原代大鼠皮层神经元分为4组:对照组(Control)、氧糖剥夺组(OGD)、ACEA+OGD组和溶剂(Vehicle)+OGD组,分别检测各组神经元损伤程度和线粒体复合体Ⅰ、Ⅱ和Ⅳ的活性。为进一步证实线粒体复合体活性对ACEA神经保护的影响,将原代大鼠皮层神经元分为5组:对照组(Control)、氧糖剥夺组(OGD)、ACEA+OGD组、线粒体复合体Ⅰ抑制剂(rotenone)+ACEA+OGD组和线粒体复合体Ⅱ抑制剂(TTFA)+ACEA+OGD组,检测和比较各组神经元细胞的损伤情况。结果:在OGD后24小时,ACEA明显增加神经元活性,减少LDH释放,降低神经元凋亡率(P<0.05),改善OGD损伤后线粒体复合体Ⅰ和Ⅳ的活性(P<0.05),而对复合体Ⅱ的活性没有影响;rotenone可以部分逆转ACEA的神经保护作用(P<0.05),但TTFA却没有这一作用。结论:ACEA可以诱导神经保护作用,其机制是与改善线粒体呼吸链复合体活性有关。

高压氧对化疗相关外周神经痛的预防作用及其机制

目的探讨高压氧可否预防化疗相关外周神经痛(CIPNP),同时,以脊髓大麻素受体(CBRs)为主要靶点,探讨其作用机制。方法 75只雄性SD大鼠按随机数字表法分为5组,即空白对照组、模型对照组、高压氧干预组、高压氧+AM630组及高压氧+AM251组,每组15只。CIPNP模型采取紫杉醇腹腔注射法建立,所有干预组从第1次紫杉醇注射开始,隔日应用高压氧干预,共5次。高压氧+AM630组和高压氧+AM251组于每次高压氧干预前分别给予大麻素Ⅱ型受体(CBR2)阻滞剂AM630和大麻素Ⅰ型受体(CBR1)阻滞剂AM251腹腔注射。行为学测试使用von fery纤维毛分别于实验开始前及实验期间每隔7 d测试大鼠机械缩足阈值(MWT);应用Western blotting检测脊髓CBR1、CBR2的表达;应用免疫组化及Western blotting检测脊髓星形胶质细胞标志物胶质纤维酸性蛋白(GFAP)的表达;应用酶联免疫吸附法(ELISA)检测脊髓炎性细胞因子白细胞介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)的表达。结果与空白对照组相比,模型对照组MWT明显降低,差异有统计学意义(P<0.01),实验第21天差异最明显[(15.46±2.83)gvs.( 4.33±3.53)g],差异有统计学意义(P<0.01);脊髓GFAP、IL-1β、TNF-α表达均明显升高,差异有统计学意义(P<0.05或P<0.01)。与模型对照组相比,高压氧干预组MWT及脊髓CBR2均明显升高,差异有统计学意义(P<0.05);脊髓GFAP、IL-1β、TNF-α表达均明显降低,差异有统计学意义(P<0.05);腹腔注射AM630可逆转上述作用,而腹腔注射AM251无类似作用。结论高压氧可以预防紫杉醇诱导的CIPNP,其机制可能与高压氧激活脊髓CBR2,并进一步阻断脊髓胶质细胞活化及炎性细胞因子表达有关。