1,6-二(4-苯乙基-1-甲基-1-哌嗪基)己烷二溴化物镇痛作用及机制探讨

目的　研究哌嗪类新化合物 1,6 二 ( 4 苯乙基 1 甲基 1 哌嗪基 )己烷二溴化物 ( 97 9 G4 )的镇痛作用及机制。方法　扭体法、热板法研究镇痛活性 ;联合给药观察纳洛酮、利血平、阿托品、CaCl2 和EDTA等对 97 9 G4镇痛作用的影响 ;并测定 97 9 G4对小鼠体内PGE2 的影响。结果　sc 97 9 G4 5mg/kg即可有效抑制小鼠扭体反应 (P <0 .0 5 ) ;sc 4 0mg/kg和icv 2 .5 μg/kg均可明显延长热板实验的舔足阈 (P <0 .0 5 ) ;纳洛酮、CaCl2 和EDTA均可拮抗、减弱或加强其镇痛作用 ;利血平、阿托品对97 9 G4的镇痛作用影响不明显。结论　 97 9 G4具有明显的镇痛活性 ,其镇痛作用与阿片受体及体内Ca2 +等因素有一定关系。     

1,6-二(4-苯乙基-1-甲基-1-哌嗪基)己烷二溴化物镇痛作用及机制探讨

目的　研究哌嗪类新化合物1,6-二( 4-苯乙基1-甲基-1-哌嗪基)己烷二溴化物(97-9-G4)的镇痛作用及机制。方法　扭体法、热板法研究镇痛活性;联合给药观察纳洛酮、利血平、阿托品、CaCl₂和EDTA等对97-9G4镇痛作用的影响;并测定97-9-G4对小鼠体内PGE₂的影响。结果　sc 97-9-G4 5mg/kg即可有效抑制小鼠扭体反应(P<0.05) ;sc 40mg/kg和icv 2.5μg/kg均可明显延长热板实验的舔足阈(P<0.05) ;纳洛酮、CaCl₂和EDTA均可拮抗、减弱或加强其镇痛作用;利血平、阿托品对97-9-G4的镇痛作用影响不明显。结论　97-9-G4具有明显的镇痛活性,其镇痛作用与阿片受体及体内Ca²⁺等因素有一定关系。     

青藤碱对吗啡依赖小鼠、大鼠及豚鼠离体回肠催促戒断反应的影响

目的 :研究青藤碱 (sinomenine ,SIN)对吗啡依赖小鼠、大鼠及豚鼠离体回肠催促戒断反应的抑制作用。方法 :连续递增sc吗啡 (morphine ,Mor) ,建立大鼠、小鼠及豚鼠吗啡身体依赖性模型 ;纳洛酮 (naloxone,Nal)催促诱发吗啡身体依赖性豚鼠离体回肠的戒断性收缩。结果 :(1)SIN 14.3 - 143mg·kg- 1 显著抑制纳洛酮催促后 3 0min内小鼠的跳台次数 ;(2 )SIN 10 0mg·kg- 1 降低纳洛酮催促后 1h内大鼠的戒断症状分值及抑制体重下降 ;(3 )SIN(1.5×10 - 4 - 6.0× 10 - 4 mol·L- 1 )剂量依赖性地抑制纳洛酮催促诱发的吗啡身体依赖性豚鼠离体回肠的戒断性收缩 ;(4)吗啡身体依赖性豚鼠ipSIN(87.0和 8.7mg·kg- 1 )后 ,其离体回肠经纳洛酮催促诱发的戒断性收缩幅值显著降低。结论 :SIN对吗啡身体依赖性大鼠、小鼠的戒断症状及豚鼠离体回肠的戒断性收缩具有抑制作用     

国产与进口二氟尼柳的实验性镇痛和抗炎作用的比较

目的 :观察国产二氟尼柳 (diflunisal)的镇痛和抗炎作用。方法 :镇痛用小鼠热板法和醋酸引起的小鼠扭体模型实验 ,抗炎用二甲苯引起的小鼠耳肿胀和角叉菜胶引起的大鼠足跖肿胀实验。结果 :镇痛实验结果表明国产二氟尼柳可显著延长小鼠热板法的痛阈值 ,抑制醋酸引起小鼠扭体模型的ED50 为 1 2 .46mg·kg-1(9.79～ 1 5 .86mg·kg-1) ;抗炎实验表明二氟尼柳抑制二甲苯引起小鼠耳肿胀的ED50 为 1 1 .1 0mg·kg-1(8.93～1 3 .81mg·kg-1) ,抑制角叉菜胶引起大鼠足跖肿胀的ED50 (用药后 6h)为 1 0 .5 6mg·kg-1(8.47～ 1 3 .1 7mg·kg-1)。结论 :国产二氟尼柳的镇痛和抗炎作用与进口品相近。     

昂丹司琼对异氟烷催眠和镇痛作用的影响

目的观察昂丹司琼对异氟烷催眠和镇痛作用的影响;探讨异氟烷的催眠、镇痛作用与5-羟色胺3受体(5-HT3)的关系。方法①催醒实验小鼠ip给予昂丹司琼1,2,4 mg·kg-1,15 min后ip给予异氟烷1.0 ml.kg-1催眠,检测翻正反射消失时间。②催眠半数有效量ED50测定小鼠ip给予昂丹司琼2 mg·kg-1,15 min后用序贯法ip给予异氟烷1.12,0.90,0.72,0.58和0.46 ml.kg-1,测定催眠ED50。③扭体法小鼠ip给予昂丹司琼1,2和4 mg·kg-1,10 min后sc给予异氟烷1.0 ml.kg-1镇痛,检测扭体次数。④热板法小鼠ip给予昂丹司琼1,2和4 mg·kg-1,10 min后,ip给予异氟烷0.4 ml.kg-1镇痛,检测小鼠热板法痛阈值(HPPT)。结果与正常对照组相比,昂丹司琼1,2和4 mg·kg-1组小鼠翻正反射消失持续的时间和ED50值均无明显变化。扭体实验中,与正常对照组比较,昂丹司琼4 mg·kg-1和异氟烷1.0 ml.kg-1可使清醒小鼠扭体次数减少(P<0.01),麻醉小鼠给予昂丹司琼1,2和4 mg·kg-1时,扭体次数有下降趋势,但无统计学差异。热板法中,ip昂丹司琼对清醒小鼠及异氟烷小鼠的HPPT均无明显影响。结论昂丹司琼对异氟烷催眠、抗热刺激伤害作用无明显影响,提示异氟烷的催眠镇痛作用可能与5-HT3受体无明显关系。     

鞘内注射士的宁对丙泊酚镇痛作用的影响

目的　探讨脊髓甘氨酸受体与丙泊酚镇痛作用的关系。方法　以热板法和扭体法测小鼠痛阈的变化 ,观察鞘内注射 (it)不同剂量士的宁对丙泊酚小鼠痛阈的影响。结果　丙泊酚 12 5mg·kg-1腹腔注射 (ip)对小鼠热板法痛阈 (painthresholdinhot platetest,HPPT)无影响 (P >0 0 5 ) ,2 5、5 0mg·kg-1可使小鼠HPPT增加 (P <0 0 5 ) ;丙泊酚 5mg·kg-1静脉注射 (iv)对小鼠扭体次数无影响 (P >0 0 5 ) ,7 5、10mg·kg-1iv可使小鼠扭体次数减少 (P <0 0 5 )。士的宁0 2 5 μgit对丙泊酚小鼠 (5 0mg·kg-1,ip)HPPT无影响 (P>0 0 5 ) ;0 5、0 75、1 0 μgit均可减少丙泊酚小鼠的HPPT(P <0 0 5 )。士的宁 0 2 5、0 5、0 75、1 0 μgit对丙泊酚小鼠 (10mg·kg-1,iv)扭体次数均无影响 (P >0 0 5 )。结论　丙泊酚在热板法和扭体法中产生不同的镇痛作用 ,前者可能与脊髓甘氨酸受体有关 ,后者与脊髓甘氨酸受体关系不大     

三氟拉嗪的抗伤害作用及其作用机理

应用小鼠热板法和醋酸扭体法伤害实验 ,评价三氟拉嗪的抗伤害作用 ,并对其作用机理进行探讨 .结果表明 :在热板法伤害实验中 ,三氟拉嗪 (2～ 2 0mg·kg- 1)剂量依赖性地延长热板伤害反应的潜伏期 ,三氟拉嗪 (2mg·kg- 1)和吗啡 (1,3和 6mg·kg- 1)合并使用 ,增加吗啡抗伤害的作用和效率(2 9.4 %～ 5 4 .4 % ) ;在醋酸扭体法伤害实验中 ,三氟拉嗪 (0 .1～ 3mg·kg- 1)非常显著地抑制醋酸伤害刺激所致小鼠扭体反应的次数 ,增加扭体反应的潜伏期 ,呈剂量依赖性 .进一步研究结果表明 :μ受体拮抗剂纳洛酮 (1～ 9mg·kg- 1)和多巴胺 1(DA1) /多巴胺 2 (DA2 )受体激动剂阿扑吗啡 (1～ 9mg·kg- 1)对三氟拉嗪的抗伤害作用无翻转作用 .这些结果提示 :三氟拉嗪具有一定的抗伤害刺激的药理作用 ,但是中枢神经系统中的 μ受体和DA2 受体不参与三氟拉嗪的抗伤害作用     

精氨酸及精氨酸脱羧酶抗体对痛阈及吗啡镇痛作用的影响(英文)

目的进一步阐明胍丁胺对阿片药理作用的影响。方法采用小鼠醋酸扭体法、小鼠热辐射甩尾法、小鼠热板法评价了精氨酸及精氨酸脱羧酶抗体对痛阈、吗啡镇痛及其耐受作用的影响。结果在小鼠醋酸扭体实验中,脑室注射精氨酸能剂量依赖性地抑制小鼠扭体次数,最大抑制率达84 %。在小鼠热辐射甩尾模型中,精氨酸不影响小鼠的甩尾时间,但能剂量依赖性地增强吗啡的镇痛作用,使吗啡2 .5 mg·kg-1的最大可能镇痛百分率从23 %增加到71 %。此外,在小鼠热辐射甩尾实验中,精氨酸能抑制吗啡100 mg·kg-1所诱导的急性耐受。精氨酸上述作用可被咪唑啉受体拮抗剂咪唑克生(3mg·kg-1,ip)所抑制。在小鼠热辐射甩尾实验和小鼠55℃热板实验中,精氨酸脱羧酶抗体能抑制吗啡镇痛,并能加重吗啡所致的耐受。结论上述结果提示,精氨酸及精氨酸脱羧酶在痛阈、吗啡镇痛及吗啡依赖形成过程中具有重要作用。     

维拉帕米、硝苯啶和粉防己碱加强吲哚美辛的镇痛作用

研究维拉帕米(Ver)、硝苯啶(Nif)粉防已碱(Tet)对吲哚美辛(Ind)镇痛作用的影响。用冰醋酸和MgSO_4分别致小鼠扭体模型.Ind、Nif、ver及Tet都表现镇痛作用。在MgSO_4 致扭体模型上除Ver外,Nif、Tet分别与Ind合用均可显著提高镇痛效应。小鼠热板模型,10mg·kg~(-1)Jnd无镇痛作用,但和Ver合用.其镇痛作用显著加强。在小鼠甩尾模型上,10mg·kg~(-1)Ind及20、40 mg·kg~(-1)的Nif均无显著的镇痛效应.但二者分别合用,其镇痛作用都很显著。在小鼠热板和甩尾模型上,icv Ver、Nif、Tet均有显著的镇痛作用,提示Vet、Nif、Tet的镇痛作用可能有中枢机制参与。     

褪黑素镇痛的相关机制

目的　探讨褪黑素 (MT)镇痛作用与内源性阿片肽、去甲肾上腺素能神经系统及钙通道的关系。方法　大鼠和小鼠痛阈的测定采用热板法 ;β 内啡肽 (β EP)的测定采用放免法 (RIA)。结果　松果腺切除后d 8大鼠痛阈的昼夜节律性消失 ,icvMT 0 2 5mg·kg-1可出现明显的镇痛作用 ;ipMT(10 0mg·kg-1) 1h后下丘脑、垂体 β EP含量均明显降低 ;ip利血平 (3mg·kg-1)可使MT镇痛作用消失 ,而sc酚妥拉明 (10mg·kg-1)可减弱MT的镇痛作用 ;CaCl2 (2 30mg·kg-1)与MT(40mg·kg-1)合用时 ,可使MT的镇痛作用减弱 ,EGTA (180mg·kg-1)及维拉帕米 (15mg·kg-1)则可使之加强。结论　MT的镇痛作用可能与内源性阿片肽、去甲肾上腺素能神经系统及Ca2 + 通道等有关     

Central components in the antinociceptive activity of dipyrone in mice

Dipyrone is classified as a nonsteroidal anti-inflammatory drug. It has analgesic, antipyretic and anti-inflammatory properties and exerts its analgesic effect via both peripheral and central action. Dipyrone at the dose of 250 and 500 mg/kg showed dose-dependent antinociceptive activity in the hot plate, tail flick tests to radiant heat and tail clip test and the writhing test induced by acetic acid in mice. The antinociceptive effects of dipyrone (500 mg/kg) were antagonized by naloxone (1, 2, 5 mg/kg) in the tail flick test to radiant heat and tail clip test and hot plate tests but not in the writhing test. Cyproheptadine (100 g/kg) decreased the antinociceptive effect of dipyrone. There was an increase in the antinociceptive effects of dipyrone (500 mg/kg) when combined with buspiron (0.5 mg/kg) in the tail flick test to radiant heat and tail clip test. The results provide evidence for a central antinociceptive effect of dipyrone antagonized by naloxone which suggests that its activity may also involve the serotoninergic system.     

PRELIMINARY STUDY ON THE ANTINOCICEPTIVE EFFECT OF ELEPHANT β-ENDORPHIN

1. Intraventricular administration of human beta-endorphin and elephant beta-endorphin significantly prolonged the tail flick response tested 30 min later. However, elephant beta-endorphin was about 7-8 times more potent than human beta-endorphin in the tail flick test. 2. beta-Endorphin antagonized the antinociceptive effect of both human beta-endorphin and elephant beta-endorphin by the same extent. Naloxone also antagonized the antinociceptive effects of the beta-endorphins but it was less effective than beta-endorphin. 3. Human beta-endorphin and elephant beta-endorphin were of equal potency in inhibiting the abdominal constriction response induced by intraperitoneal (i.p.) acetic acid. Both beta-endorphin and naloxone antagonized these effects of the beta-endorphins with naloxone being more effective. 4. The present study showed that different opioid receptor subtypes may be involved in the tail flick test and the abdominal constriction test. Furthermore, elephant beta-endorphin was a better antinociceptive agent than human beta-endorphin in the tail flick test.     

Gender and test dependence of a type of kappa mediated stress induced analgesia in mice

1. In male mice, 80 inescapable footshocks (S-80) induce analgesic responses measured by the tail flick test that are blocked by naloxone and the kappa opioid antagonist, nor-binaltorphimine. We now study the nociceptive responses, induced after this particular stress, measured by the writhing test, the tail immersion test and a high intensity tail immersion test both in male and female mice.2. In stressed males, analgesic responses are seen in all the nociceptive tests. Naloxone (10 mg/kg) does not prevent them.3. In stressed females, in contrast with males, no analgesia is produced in the tail flick test. The writhing test and the tail immersion test registered analgesic responses that were not prevented by naloxone (10 mg/kg).4. We conclude that only the antinociceptive kappa opioid mediated component of the stress we study is strongly dependent on gender, in contrast to other types of analgesia triggered by the same stress.     

Analgesic activity of the ethanolic extract of Shorea robusta resin in experimental animals

Aim:

Shorea robusta (Sal), an important traditional Indian medicinal plant used in various ailments and rituals and the indigenous use of the resin of this plant as a medicament for treatment of various inflammatory conditions is well documented in literature. In the present study, ethanolic extract of S. robusta resin (SRE) was evaluated for its analgesic activity by making use of different central and peripheral pain models.

Materials and Methods:

The analgesic activity of SRE was assessed by employing different pain models such as, i) hot plate and tail flick tests for central analgesia, ii) acetic acid- induced writhing (peripheral analgesic model), iii) formalin-induced hind paw licking (both central and peripheral model), iv) carrageenan-induced hyperalgesia (peripheral analgesic model) and v) post-surgical pain (peripheral analgesic model).

Results:

The extract produced significant central and peripheral analgesic effects, as is evident from increase in reaction time in hot plate and tail flick tests, inhibition in writhing counts in acetic acid-induced writhing test, inhibition of licking time in formalin-induced hind paw licking, increased pain threshold in paw withdrawal latency in carrageenan-induced hyperalgesia and increased paw withdrawal threshold in post-surgical pain.

Conclusion:

The results of the present study demonstrate marked antinociceptive effects of SRE.KEY WORDS: Carrageenan, hot plate, post-surgical pain, resin, Shorea robusta, tail flick     

Antinociceptive activity of Vitex-negundo Linn leaf extract

Tail flick test in rats and acetic acid induced writhing in mice were employed to study the antinociceptive activity of ethanolic leaf extract of Vitex-negundo (VN) (100, 250 and 500 mg/kg, p.o). The effect was compared with meperidine (40 mg/kg, sc) in tail flick method and aspirin (50 mg/kg, p.o) in writhing test as a standard control respectively. An interaction with naloxone hydrochloride was also studied in tail flick method for its mechanism of central analgesic action. The test drug showed significant analgesic activity in dose dependant manner in both the experimental models. In comparison to standard drug (meperidine), more than ten times dose of VN extract was required to produce comparable significant antinociceptive activity. The sub-effective dose (5 mg/kg, po) of VN potentiated the analgesic activity of meperidine (4 mg/kg, sc) and aspirin (25 mg/kg, po). Naloxone (1 mg/kg, sc) did not reverse the analgesic effect of VN extract. Our observations suggest that VN possesses both central and peripheral analgesic activity. The central analgesic action does not seem to be mediated through opioid receptors. It, may prove to be a useful adjuvant therapy along with standard analgesic drug.     

Baclofen analgesia in mice: a GABAB-mediated response.

The effect of baclofen, a GABAB agonist, has been studied in three antinociceptive tests (tail flick latency, hot plate method and acetic acid-induced writhing) in mice. In all three models, baclofen was found to elicit a dose-dependent antinociceptive effect. The observed antinociceptive effect was stereospecific, as the levo isomer of baclofen was found to be more potent than the racemic mixture. Baclofen also potentiated morphine analgesia. The antinociceptive effect of baclofen was reversed by both CGP 35348, a GABAB antagonist, and naloxone, an opioid antagonist, but not by bicuculline or picrotoxin, GABAA antagonists. However, in acetic acid-induced writhing, naloxone failed to reverse baclofen analgesia. The data suggest that the antinociceptive effect of baclofen is GABAB receptor-mediated and that there may be a GABAergic and opiate/or non-opiate interaction in eliciting the analgesic effect.     

白芍总甙的镇痛作用

白芍总甙(TGPs 5～40mg/kg)呈剂量依赖性抑制小鼠扭体、嘶叫、热板反应,并在50～125mg/kg时抑制大鼠热板反应,作用高峰在0.5～1h,还分别加强吗啡、可乐定抑制小鼠扭体作用,但纳洛酮(2mg/kg)不影响TGPs的镇痛作用,TGPs(0.25～0.5μg/ml)亦不影响低频场刺激的豚鼠回肠纵肌收缩。提示TGPs有镇痛作用,但可能不是由于兴奋阿片受体所致。