NO介导吗啡戒断大鼠脊髓Fos蛋白和NMDA_(1A)受体mRNA表达的增加

目的:观察NO在纳洛酮催促吗啡戒断大鼠脊髓神经元活动变化中的作用。方法:采用Fos免疫组织化学、NADPH-d组织化学、Fos/NADPH-d双标、鞘内注射、反义寡核苷酸和RT-RCR技术。结果:急性应用纳洛酮和慢性应用吗啡对大鼠脊髓Fos蛋白及NADPH-d阳性神经元表达无明显影响,二者也无Fos/NADPH-d双标神经元表达;纳洛酮催促吗啡戒断大鼠脊髓Fos蛋白、NADPH-d阳性神经元、纤维和终末表达明显增加,且出现Fos/NADPH-d双标神经元表达。预先鞘内注射nNOS反义寡核苷酸明显降低吗啡戒断症状评分,减少吗啡戒断大鼠脊髓Fos蛋白及NMDA_(1A)R mRNA表达。结论:NO介导吗啡戒断大鼠脊髓Fos和NMD_(1A)R mRNA表达的增加。     

吗啡戒断时M2毒蕈碱受体介导大鼠蓝斑核中nNOS表达增强

目的:观察脊髓不同M受体亚型对纳络酮催促吗啡戒断大鼠戒断症状评分以及蓝斑核nNOS表达变化的影响.方法:采用nNOS免疫组织化学、鞘内注射和反义寡核苷酸技术.结果:鞘内注射M_2-AS可显著减少吗啡戒断症状评分,M_1-AS虽可部分减轻戒断症状,但总的作用弱于 M_2-AS;吗啡依赖大鼠蓝斑核nNOS表达增加,用纳络酮催促戒断后nNOS表达进一步增加,鞘内注射M_2-AS可抑制在吗啡戒断时蓝斑核nNOS的表达增强,而M_1-AS对其无影响.结论:脊髓M_2受体介导吗啡戒断大鼠蓝斑核nNOS的表达增加.     

定志丹对吗啡依赖大、小鼠戒断症状的控制作用

目的 :观察及评价中药制剂定志丹对吗啡依赖小鼠、大鼠催促戒断症状的控制作用。方法 :按文献采用剂量递增法建立吗啡依赖小鼠、大鼠模型。末次注射吗啡后 ,给大、小鼠ig不同剂量的定志丹 ,给药后大、小鼠分别在4 0min和 30minip纳洛酮进行催促戒断 ,记录戒断症状及体重变化。实验设立了生理盐水和可乐定对照组 ;大鼠还设立了吗啡组。结果 :定志丹 10 - 2 0g·kg- 1 能显著减少吗啡依赖小鼠经纳洛酮催促出现的跳跃反应的次数 ,抑制率 39.6 % - 6 7.9% ,跳跃反应后空白对照组小鼠的体重明显减轻 (P <0 .0 1) ,而定志丹各剂量组试验前后的体重均无显著性差异 ,(P >0 .0 5 )。与空白对照组比较 ,定志丹 10 - 2 0g·kg- 1 使吗啡依赖大鼠的催促戒断症状分值明显降低 (P <0 .0 5 ) ,定志丹 2 0g·kg- 1 使各种症状发生的总次数减少 35 .3%。与空白对照组比较 ,阳性对照药可乐定组的跳跃反应潜伏时间明显延长 (P <0 .0 5 ) ;而定志丹各剂量组的跳跃反应潜伏时间虽有一定延长 ,但无统计学意义(P >0 .0 5 )。结论 :定志丹对吗啡依赖小鼠、大鼠催促戒断症状有明显的抑制作用 ,对吗啡依赖动物的体重下降有显著的缓解作用     

鞘内注射右美托咪啶对吗啡戒断大鼠脊髓nNOS表达的影响

目的 观察鞘内注射右美托咪啶对吗啡依赖大鼠纳洛酮催促戒断反应和脊髓神经元型一氧化氮合酶(nNOS)表达的影响.方法 建立大鼠吗啡依赖和戒断模型,分为正常对照(C)组、吗啡依赖(MD)组、吗啡戒断(MW)组和右美托咪啶(DEX)组,采用行为学(n=8)、免疫组织化学(n=6)和Western blot法(n=4)观察鞘内注射右美托咪啶对吗啡依赖大鼠纳洛酮催促戒断反应和脊髓nNOS表达的影响.结果 鞘内注射右美托咪啶可减轻吗啡依赖大鼠戒断症状:MW组戒断症状评分为(28.6±4.9)分,高于DEX组的(17.8±3.8)分(P＜0.05);MW组促诱发痛(TEA)评分为(13.5±2.6)分,高于DEX组的(8.6±2.5)分(P＜0.05).鞘内注射右美托咪啶可减少脊髓背角nNOS阳性神经元的数目:DEX组为(180±31)个,低于MW组的(238±40)个(P＜0.05);DEX组脊髓nNOS蛋白表达也减少.结论 右美托咪啶能抑制吗啡戒断大鼠脊髓nNOS表达.     

L-四氢巴马汀抑制羟考酮依赖的小鼠和大鼠戒断症状的实验研究

目的:观察l-四氢巴马汀对羟考酮依赖动物催促戒断症状的影响.方法:以连续递增给药建立羟考酮依赖小鼠和大鼠模型,l-四氢巴马汀伴随给药,观察1-四氢巴马汀对羟考酮依赖动物戒断反应的影响.结果:l-四氢巴马汀40、60 mg·kg-1能明显抑制羟考酮依赖小鼠戒断跳跃反应和体重的降低;20、30mg·kg-1也能显著降低纳络酮催促戒断所致羟考酮依赖大鼠的戒断症状和体重下降.在两种动物模型上,1-四氢巴马汀抗羟考酮依赖作用强度均有剂量相关性.结论:l-四氢巴马汀可抑制羟考酮躯体依赖的形成.     

褪黑素抗吗啡戒断反应及其对中脑导水管周围灰质β-内啡肽的影响

目的:观察褪黑素(MEL)抗小鼠吗啡依赖戒断反应与其对脑内中脑导水管周围灰质(PAG)中β-内啡肽(β-EP)影响之间的关系,以探讨MEL抗戒断反应的中枢机制。方法:采用剂量递增法连续皮下注射(sc)吗啡建立小鼠吗啡依赖模型,sc纳洛酮催促戒断,以小鼠体重下降和戒断跳跃次数为指标观察MEL抗小鼠吗啡依赖戒断反应的效应;采用放射免疫分析法,检测小鼠中脑导水管周围灰质β-EP含量。结果:(1)连续8d腹腔注射(ip)10,20,40mg.kg-1的MEL能剂量依赖性地抑制吗啡依赖小鼠的戒断症状;(2)吗啡依赖组小鼠脑内PAG中β-EP含量明显低于生理盐水对照组;(3)连续8dip20mg.kg-1MEL的小鼠,其PAG中β-EP含量明显高于吗啡依赖组小鼠。结论:MEL可减弱小鼠吗啡依赖戒断反应,这种效应可能与其增加脑内PAG中β-EP的含量有关。     

慢性吗啡处理对大鼠交感神经节cAMP、cGMP水平的影响

目的观察慢性吗啡(Mor)处理对大鼠交感神经节——颈上神经节(SCG)环腺苷酸(cAMP)和环鸟苷酸(cGMP)含量的影响。方法剂量递增法连续皮下注射(sc)吗啡5 d建立慢性吗啡依赖大鼠模型,纳洛酮(Nal)催促戒断法和55℃热水甩尾试验判断模型依赖性和耐受性,125I放射性免疫测定法测定SCG中cAMP和cGMP的含量。结果①吗啡急性给药组大鼠SCG中cAMP含量较正常对照组降低(P<0.05);②吗啡依赖组大鼠SCG中cAMP含量回到正常对照组水平,并有增高趋势(与正常对照组比较,P>0.05;与吗啡急性给药组比较,P<0.05);③吗啡戒断组大鼠SCG中cAMP含量较正常对照明显增高(P<0.05);④各组大鼠SCG的cGMP含量差异无显著性(P>0.05)。结论慢性吗啡处理大鼠交感神经节cAMP存在适应性上调现象。     

MK-801对吗啡依赖大鼠戒断症状及中枢cAMP含量的影响

目的观察MK-801对吗啡依赖大鼠戒断症状及脊髓和脑干cAMP含量的影响。方法选择♂性SD大鼠32只,随机分为盐水对照组、吗啡依赖组、吗啡戒断组和MK-801组,每组8只。各组在纳洛酮激发戒断后立即观察戒断症状30min,纳洛酮激发戒断后1h,处死大鼠,分离脊髓和脑干,用放射免疫法检测cAMP的含量。结果MK-801组戒断症状总分为26.06±1.98,低于吗啡戒断组61.15±3.28(P<0.01)。MK-801组脊髓cAMP含量为0.8±0.26μmol.g-1,低于吗啡戒断组(P<0.05),而与吗啡依赖组相近(P>0.05);MK-801组脑干cAMP含量为1.62±0.38μmol.g-1,低于吗啡戒断组(P<0.05),而与吗啡依赖组相近(P>0.05)。结论MK-801减轻吗啡戒断症状的机制可能与其降低大鼠中枢cAMP的水平有关。     

芋螺多肽conantokins及其类似物对小鼠吗啡戒断症状的抑制作用

目的:观察及评价NMDA受体抑制剂芋螺多肽conantokins及其类似物对吗啡依赖小鼠催促戒断症状的抑制作用。方法:采用剂量递增法皮下注射吗啡7d,建立吗啡依赖小鼠模型。观察conantokin及类似物con-G(2.5,5,10,15nmol·kg-1,icv),con-G[S16Y]〗(15nmol·kg-1,icv),con-R(1-17)(15,30nmol·kg-1,icv),对照药美金胺(46.3μmol·kg-1,ip)以及艾芬地尔(1.25μmo·lkg-1,icv;25μmol·kg-1,ip)对吗啡依赖小鼠纳洛酮催促戒断的跳跃次数及体重的影响。结果:与吗啡依赖组相比,icv15nmo·lkg-1con-G使吗啡依赖小鼠平均跳跃次数减少89.0%,并呈剂量依赖性(2.5-15nmo·lkg-1);icv15nmol·kg-1con-G[S16Y]〗可完全抑制吗啡依赖小鼠戒断跳跃。con-R(1-17)(15-30nmol·kg-1,icv)使吗啡依赖小鼠平均跳跃次数仅减少40.2%-58.3%。结论:con-G、con-G[S16Y]〗和con-R(1-17)对抑制小鼠的戒断症状非常有效。相对于con-R(1-17),con-G和con-G[S16Y]〗对小鼠的戒断症状的抑制作用更强,这是由于con-G、con-G[S16Y]〗对NMDA受体NR2B亚基的选择性更高。Conantokins及其类似物在抑制吗啡依赖方面很有潜力。     

The spinal nitric oxide involved in the inhibitory effect of midazolam on morphine-induced analgesia tolerance

Previous studies had shown that pretreatment with midazolam inhibited morphine-induced tolerance and dependence. The present study was to investigate the role of spinal nitric oxide (NO) in the inhibitory effect of midazolam on the development of morphine-induced analgesia tolerance. Subcutaneous injection of 100 mg/kg morphine to mice caused an acute morphine-induced analgesia tolerance model. To develop chronic morphine tolerance in mice, morphine was injected for three consecutive days (10, 20, 50 mg/kg sc on Day 1, 2, 3, respectively). In order to develop chronic tolerance model in rats, 10 mg/kg of morphine was given twice daily at 12 h intervals for 10 days. Midazolam was intraperitoneally injected 30 min prior to administration of morphine. Tail-flick test, hot-plate and formalin test were conducted to assess the nociceptive response. Immunocytochemistry, histochemistry and western blot were performed to determine the effect of midazolam on formalin-induced expression of Fos protein, nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) and nitric oxide synthase (NOS) in chronic morphine-tolerant rats, respectively. The results showed that pretreatment with midazolam significantly inhibited the development of acute and chronic morphine tolerance in mice, which could be partially reversed by intrathecal injection of NO precursor L-arginine (L-Arg). In chronic morphine-tolerant rats, pretreatment with midazolam significantly decreased the formalin-induced expression of Fos and Fos/NADPH-d double-labeled neurons in the contralateral spinal cord and NADPH-d positive neurons in the bilateral spinal cord. Both inducible NOS (iNOS) and neuronal NOS (nNOS) protein levels in the spinal cord were significantly increased after injection of formalin, which could be inhibited by pretreatment with midazolam. The above results suggested that the decrease of the activity and expression of NOS contributed to the inhibitory effect of midazolam on the development of morphine tolerance.     

Involvement of cyclic AMP systems in morphine physical dependence in mice: prevention of development of morphine dependence by rolipram, a phosphodiesterase 4 inhibitor

In this study, we examined whether morphine dependence was inhibited by rolipram, a cyclic AMP selective phosphodiesterase inhibitor in mice, since a role for the cyclic AMP systems in the development of morphine dependence has been reported. Mice, which received morphine (10 mg kg(-1) s.c.) twice a day for 5 days showed withdrawal syndromes such as jumping, rearing and forepaw tremor following naloxone challenge (5 mg kg(-1) i.p.) on the 6th day. Such mice exhibited a significant elevation of cyclic AMP levels in the thalamus compared to control mice. However, co-administration of rolipram (1 mg kg(-1) i.p.) with morphine for 5 days significantly attenuated the severity of the withdrawal syndrome and the increase in the cyclic AMP levels after the administration of naloxone. In na?ve mice, acute morphine treatment (10 mg kg(-1) s.c.) decreased cyclic AMP levels in the thalamus and cerebral cortex 10 min later. The decrease of cyclic AMP levels induced by acute morphine treatment was blocked by co-administration of rolipram (1 mg kg(-1) i.p.). However, acute rolipram did not affect the naloxone-precipitated morphine withdrawal syndrome. These results suggest that the elevation of the cyclic AMP levels is involved in the development of morphine withdrawal syndrome and that blockade of the morphine-induced reduction of cyclic AMP levels by chronic rolipram inhibits the development of dependence and the behavioural and biochemical changes induced by naloxone. Furthermore, rolipram may be a useful drug for attenuating the development of morphine dependence.     

The mechanisms of morphine dependence and it's withdrawal syndrome: study in mutant mice

To investigate the involvement of catecholamines and/or the cyclic AMP (cAMP) systems in the development of drug dependence, we examined whether morphine dependence was developed in tyrosine hydroxylase (TH) heterozygous (TH+/-) and cAMP response element binding protein (CREB) binding protein (CBP) heterozygous (CBP+/-) mice. Morphine (10 mg/kg) induced place preference in the wild-type mice. In the TH+/- and CBP+/- mice, however, we could not find any morphine-induced place preference. When the wild-type mice pretreated with morphine (10 mg/kg) twice a day for 5 days were challenged with naloxone (5 mg/kg), they showed increased numbers of jumping, rearing and forepaw tremor as a sign of withdrawal symptom and increased level of cAMP in the thalamus/hypothalamus, but not in the striatum. However, increased numbers of jumping and forepaw tremor in the TH+/- and CBP+/- mice and increased level of cAMP in the thalamus/hypothalamus of TH+/- mice were not observed. These results suggest that catecholamines and CBP are involved in the development of morphine dependence, and that some changes in the catecholaminergic and/or cAMP system induced by repeated morphine treatment play an important role in the addiction of morphine.     

Spinal administration of lipoxygenase inhibitors suppresses behavioural and neurochemical manifestations of naloxone-precipitated opioid withdrawal

1. This study investigated the role of spinal lipoxygenase (LOX) products in the induction and expression of opioid physical dependence using behavioural assessment of withdrawal and immunostaining for CGRP and Fos protein expression in the spinal cord. 2. Administration of escalating doses (5-50 mg kg-1; i.p.) of morphine for 5 days markedly elevated CGRP-like immunoreactivity in the dorsal horn of the rat spinal cord. Naloxone (2 mg kg-1; i.p.) challenge precipitated a robust withdrawal syndrome that depleted CGRP-like immunoreactivity and increased the number of Fos-like immunoreactive neurons in the dorsal horn. 3. Intrathecal administration of NDGA (10, 20 microg), a nonselective LOX inhibitor, AA-861 (1.5, 3 microg), a 5-LOX selective inhibitor, or baicalein (1.4, 2.8 microg), a 12-LOX selective inhibitor, concurrently with systemic morphine for 5 days or as a single injection immediately preceding naloxone challenge, blocked the depletion of CGRP-like immunoreactivity, prevented increase in the number of Fos-like immunoreactive neurons in the dorsal horn, and significantly attenuated the morphine withdrawal syndrome. 4. The results of this study suggest that activity of LOX products, at the spinal level, contributes to the expression of opioid physical dependence, and that this activity may be expressed through increased sensory neuropeptide release.     

The effects of thyrotropin-releasing hormone on the central nervous system responses to chronic morphine administration

The effects of thyrotropin-releasing hormone (TRH) on abrupt and naloxone-precipitated abstinece symptoms were determined in male Swiss-Webster mice rendered dependent on morphine by SC implantation of morphine pellets. Intracerebral (IC) administration of TRH inhibited the hypothermic response observed during abrupt (removal of morphine pellets) and naloxone (0.1 mg/kg SC) precipitated withdrawal. IC injection of TRH also inhibited the naloxoneprecipitated withdrawal jumping response as evidenced by increases in the dose of naloxone required to elicit the response. The effects of TRH on the development of morphine dependence were also investigated. A single SC injection of TRH (4–16 mg/kg) did not modify development of morphine dependence. Administration of TRH prior to and during morphine pellet implantation inhibited the development of dependence as evidenced by inhibition in the development of abrupt and naloxone-induced withdrawal hypothermia. Even though the hypothermic response was blocked, multiple SC administration of TRH failed to modify naloxone-induced stereotyped jumping response. These studies indicate that TRH administration can modify central nervous system responses to chronic morphine treatment and that separate sites may initiate withdrawal jumping behavior and affect temperature regulation during abrupt and antagonist-induced abstinence.This work was presented in part at the International Narcotic Research Conference, North Falmouth, Massachusetts, June 10–15, 1979     

2-MPPA,a selective glutamate carboxypeptidase II inhibitor,attenuates morphine tolerance but not dependence in C57/Bl mice

Rationale and objectives We have recently reported that conditioned morphine reward and tolerance to its antinociceptive effect, but not expression of morphine dependence, were attenuated by 2-(phosphonomethyl)pentanedioic acid (2-PMPA), a prototypic inhibitor of glutamate carboxipeptidase II (GCP II), which is an enzyme responsible for the supply of glutamate. In the present study, we investigated in more detail the effects of GCP II inhibition on opioid dependence and tolerance to its antinociceptive effect in C57/Bl mice using a novel GCP II inhibitor.Results The treatment with 2-(3-mercaptopropyl)pentanedioic acid (2-MPPA; 60 but not 10 or 30 mg/kg) prevented the development of morphine tolerance without affecting acute morphine antinociception. 2-MPPA at 30 and 60 mg/kg did not prevent the development of dependence induced by 10 and 30 mg/kg of morphine. The study on opioid withdrawal syndrome, i.e., expression of opioid dependence, demonstrated that 2-MPPA potentiated jumping behavior and teeth chattering but attenuated chewing and ptosis. None of these opioid withdrawal signs were affected by 2-MPPA in morphine nondependent mice. Pretreatment with the mGluR II antagonist LY341495 (1 mg/kg) reversed the 2-MPPA-induced increase or decrease in opioid withdrawal signs in morphine-dependent mice. 2-MPPA (60 mg/kg) administered for 7 days with morphine did not affect brain concentration of this opiate.Conclusions The present findings suggest complex effects of GCP II inhibition on morphine dependence and tolerance and imply a role of mGluR II in the actions of 2-MPPA.     

On the Mechanism(s) of Cholecystokinin (CCK): Receptor Stimulation Attenuates Morphine Dependence in Mice

Abstract: In the present study, effect of cholecystokinin (CCK) agonists and on dependence to morphine in mice has been investigated. The influence of dopaminergic, adrenergic, cholinergic and serotonergic on attenuation of naloxone-induced jumping in morphine-dependent mice by CCK agonists were also considered. Mice were treated subcutaneously with morphine (50, 50 and 75 mg/kg) three times daily (10 a.m. 1 p.m. and 4 p.m.) for 3 days, and a last dose of morphine (50 mg/kg) was administered on the 4th day. Withdrawal syndrome (jumping) was precipitated by naloxone (5 mg/kg) which was administered intraperitoneally 2 hr after the last dose of morphine. To study effects of CCK receptor agonists, 10 injection of morphine (3 administrations each day) for dependence and a dose of 5 mg/kg of naloxone for withdrawal induction were employed. The CCK agonists CCK-8 (0.001- 0.1 mg/kg), unsulfated CCK-8 (CCK-8U; 0.001-0.1 mg/kg) and caerulein (0.00001-0.01 mg/kg) were able to prevent withdrawal signs precipitated by naloxone (5 mg/kg). Sulpiride and pimozide increased response induced by CCK-8 agonists. The dopamine antagonists also attenuates jumping by themselves. SCH 23390 did not alter the CCK-8 effect, but decreased the jumping by itself. Phenoxybenzamine, propranolol, methysergide and atropine did not change the caerulein effect significantly. However, single administration of atropine increased and methysergide decreased jumping. It is concluded that CCK mechanism(s) may be involved in morphine dependence, and dopaminergic mechanism(s) may interact with CCK in attenuation of naloxone-induced jumping.     

谷氨酸钠对小鼠吗啡依赖及戒断时血浆、脑内一氧化氮的影响

目的 :探讨兴奋性氨基酸的钠盐谷氨酸钠( Glu-Na)对小鼠吗啡依赖及吗啡戒断小鼠血浆、脑内一氧化氮的影响。方法 :皮下注射定量吗啡 ,建立小鼠吗啡依赖模型 ,腹腔注射纳洛酮催瘾。在注射吗啡同时每天早 8点用不同剂量 Glu-Na给小鼠灌胃 ( ig) ,观察小鼠戒断反应中出现的跳跃反应的潜伏期、跳跃次数和体重丢失 ,评定戒断反应的强度。用硝酸还原法检测血浆和脑内NO含量。结果 :三种不同剂量 ( 1 0 0、2 0 0、4 0 0 mg/ kg)的Glu-Na对小鼠吗啡戒断有加强作用 ,并呈量效关系。吗啡戒断小鼠脑内和血浆中 NO的含量明显高于正常小鼠 ,中剂量 ( 2 0 0 mg/ kg)的 Glu-Na可进一步提高吗啡戒断小鼠脑内和血浆中 NO的含量。结论 :Glu-Na可加强小鼠吗啡依赖 ,并提高吗啡戒断小鼠血浆和脑内一氧化氮含量     

Neuropeptide trefoil factor 3 attenuates naloxone-precipitated withdrawal in morphine-dependent mice

Rationale

The persistence of physical dependence and craving in addicts is considered to contribute to relapse. Increasing evidence indicates that neuropeptide systems are associated with several phases of drug addiction, but little is known about whether the neuropeptide trefoil factor affects withdrawal symptoms.

Objectives

This study aims to investigate the potential effects of the neuropeptide trefoil factor 3 (TFF3) on naloxone-precipitated withdrawal symptoms in morphine-dependent mice.

Results

Mice received increasing doses of morphine over 3 days. On day 4, the mice were injected with TFF3 (1.0 mg/kg, i.p.) 30 min after the last dose of morphine. Thirty minutes after TFF3 treatment, naloxone (1 mg/kg, i.p.) was injected, and body weight, jumping behavior, wet-dog shakes, and locomotor activity were assessed 30 min later. Naloxone caused significant weight loss and increased jumping behavior and wet-dog shakes in morphine-dependent mice. TFF3 (1.0 mg/kg) reversed these behavioral symptoms caused by morphine withdrawal, suggesting that TFF3 might ameliorate physical dependence associated with opiate addiction. Furthermore, TFF3 pretreatment significantly reduced morphine withdrawal-induced increases in plasma corticosterone and adrenocorticotropic hormone levels. The glucocorticoid receptor agonist RU486 blocked the behavioral effects of TFF3 on morphine withdrawal symptoms. Finally, Fos expression in the medial prefrontal cortex which was decreased during morphine withdrawal was increased by TFF3 pretreatment.

Conclusion

These findings indicate that TFF3 might be a potential therapeutic candidate for opiate addiction by regulating glucocorticoid secretion and neuronal activation in the prefrontal cortex.