Antagonistic effect of orphanin FQ on opioid analgesia in rat

目的：研究孤啡肽（ＯＦＱ）对痛与阿片镇痛的影响．方法：脑室（ｉｃｖ）与鞘内（ｉｔｈ）给药，以大鼠甩尾模型测痛．结果：小剂量ＯＦＱ（０１μｇ）ｉｃｖ及ｉｔｈ给药对痛反应均无影响；较大剂量ＯＦＱ（０５－１０μｇ）可使痛反应增强．ＯＦＱ１－１０（ＯＦＱ的一个片段）ｉｃｖ对痛反应无影响．μ受体激动剂芬太尼（１μｇ）、δ激动剂ＤＳＬＥＴ（５μｇ）ｉｃｖ或ｉｔｈ给药，以及κ激动剂Ｕ５０４８８Ｈ（１μｇ）ｉｔｈ给药，可使痛阈明显增加．０１μｇ或１μｇＯＦＱ与上述药物合用后，痛阈增加明显减少（除鞘内与ＤＳＬＥＴ合用外）．结论：ＯＦＱ可增强大鼠的痛反应，在脑内对抗由μ和δ受体介导的阿片镇痛，在脊髓对抗由κ和μ但不是由δ受体介导的镇痛．     

胸部硬膜外术后镇痛的临床观察

８例开胸手术或肝部分切除术全麻病人施行硬膜外术后镇痛。病人随机分为吗啡组（吗啡２５ｍｇ）、芬太尼组（芬太尼００２５ｍｇ）和布比卡因组（０２％布比卡因５ｍｌ）。全麻结束气管拔管后硬膜外注药,分别观察注药时,注药后１、３、５、２４ｈ镇痛、镇静效果和ＭＡＰ、ＨＲ、ＲＲ、ＳｐＯ２、ＰＥｔＣＯ２。结果镇痛效果依次为吗啡组＞芬太尼组＞布比卡因组。吗啡组镇痛、镇静效果好,作用时间长,副作用发生率与其它两组比较无差异。镇痛对呼吸无明显影响,注药后血压略有下降,大多数病人循环平稳,个别病人可出现一过性血压降低。     

白介素2和肿瘤坏死因子α对大鼠C6胶质瘤细胞产生一氧化氮的影响

用Ｇｒｉｅｓｓ法检测细胞培养上清中ＮＯ÷２含量作为反映细胞产生一氧化氮（ＮＯ）量的指标，观察细菌脂多糖（ＬＰＳ），干扰素γ（ＩＦＮ－γ），肿瘤坏死因子α（ＴＮＦ－α）及白介素２（ＩＬ－２）对大鼠Ｃ６胶质瘤细胞产生ＮＯ的影响．结果Ｃ６细胞于体外培养８ｈ时可自发产生ＮＯ，２４ｈ达峰值（１７．５±１．９ｖｓ溶剂对照组６．５±１．９μｍｏｌ·Ｌ－１），４８ｈ仍有产生．在所用剂量范围，上述因素单独作用２４ｈ均不影响Ｃ６产生ＮＯ，而５－５００ｋＵ·Ｌ－１ＩＬ－２与０．５ｍｇ·Ｌ－１ＬＰＳ或５０ｋＵ·Ｌ－１ＩＦＮ－γ合用可增强Ｃ６产生ＮＯ（１０．６－１３．４ｖｓ７．２μｍｏｌ·Ｌ－１），ＬＰＳ，ＩＦＮ－γ及ＴＮＦ－α三者合用亦有一定促进Ｃ６产生ＮＯ作用．提示炎性刺激与炎性细胞因子共同作用可促进中枢神经胶质细胞产生ＮＯ．     

维拉帕米增强曲马多镇痛作用的实验研究

目的本实验旨在观察钙通道拮抗剂与曲马多联合外周应用对大鼠的镇痛效应。方法痛阈测定选用电刺激甩尾和热板法。腹腔注射不同剂量的维拉帕米（５，１０，２０ｍｇ·ｋｇ－１）、曲马多（１０，２０，４０ｍｇ·ｋｇ－１）或小剂量维拉帕米（５ｍｇ·ｋｇ－１）和不同剂量曲马多（１０，２０，４０ｍｇ·ｋｇ－１）联合注射。结果曲马多单独应用时，镇痛效应确切，在所试剂量范围内与剂量正相关。维拉帕米单用时，无论剂量大小均无镇痛作用，但小剂量（５ｍｇ·ｋｇ－１）与不同剂量曲马多联用，可显著增强曲马多的镇痛效应，缩短起效时间，延长其有效镇痛期。结论钙通道拮抗剂可增强曲马多的镇痛作用，此联合用药方法简单、方便、危险性小，有在临床推广应用的前景。     

5-HT1A受体激动剂乌拉地尔对吗啡依赖大鼠戒断反应的抑制作用

目的··：观察５－ＨＴ１Ａ受体激动剂乌拉地尔（ｕｒａｐｉｄｉｌ）和８－ＯＨ－ＤＰＡＴ及阿片μ受体激动剂美沙酮（ｍｅｔｈａｄｏｎｅ）对吗啡戒断反应的影响。方法··：采用吗啡依赖大鼠模型侧脑室注射上述药物,并用腹腔注射纳洛酮诱发戒断反应,记录戒断症状。结果··：侧脑室注射乌拉地尔可明显抑制纳洛酮诱发的吗啡躯体戒断反应,并呈量效关系。乌拉地尔抑制吗啡戒断反应的作用与８－ＯＨ－ＤＰＡＴ的作用一致。此效应与美沙酮的作用相比也基本相同。结论··：乌拉地尔通过激活５－ＨＴ１Ａ受体可以抑制吗啡戒断反应。     

Effects of dl-3-n-butylphthalide on region al cerebral blood flow in right middle cerebral artery occlusion rats

目的：观察ｄｌ３ｎ丁基苯酞（ＮＢＰ）对右大脑右中动脉阻断（ＲＭＣＡＯ）大鼠缺血区局部脑血流（ｒＣＢＦ）的影响．方法：氢清除法动态监测ＲＭＣＡＯ大鼠ｒＣＢＦ变化．结果：ＲＭＣＡＯ后１０ｍｉｎｉｐＮＢＰ（５，１０，２０ｍｇ·ｋｇ－１）可明显增加ｒＣＢＦ（与溶剂对照组相比Ｐ＜００１），４０ｍｉｎ给药有类似作用但作用较弱（与给药前相比Ｐ＜００５），６０ｍｉｎ给药不能增加ｒＣＢＦ（与给药前相比Ｐ＞００５）．此外，ＲＭＣＡＯ前４０ｍｉｎｉｐＮＢＰ也可使ＲＭＣＡＯ后不同时间点ｒＣＢＦ明显增加．尼莫地平（０５ｍｇ·ｋｇ－１，ｉｐ）与ＮＢＰ（１０ｍｇ·ｋｇ－１，ｉｐ）具有相似的作用．结论：ＮＢＰ预防给药或治疗给药能使ＲＭＣＡＯ后减少的ｒＣＢＦ明显增加．     

5-HT_(1A)受体激动剂乌拉地尔对吗啡依赖大鼠戒断反应的抑制作用

目的··：观察５－ＨＴ１Ａ受体激动剂乌拉地尔（ｕｒａｐｉｄｉｌ）和８－ＯＨ－ＤＰＡＴ及阿片μ受体激动剂美沙酮（ｍｅｔｈａｄｏｎｅ）对吗啡戒断反应的影响。方法··：采用吗啡依赖大鼠模型侧脑室注射上述药物,并用腹腔注射纳洛酮诱发戒断反应,记录戒断症状。结果··：侧脑室注射乌拉地尔可明显抑制纳洛酮诱发的吗啡躯体戒断反应,并呈量效关系。乌拉地尔抑制吗啡戒断反应的作用与８－ＯＨ－ＤＰＡＴ的作用一致。此效应与美沙酮的作用相比也基本相同。结论··：乌拉地尔通过激活５－ＨＴ１Ａ受体可以抑制吗啡戒断反应。     

不同剂量云芝糖肽对小鼠痛阈、游泳耐力和免疫功能的影响

目的：在体研究不同剂量（０．５、１、５、８ｇ·ｋｇ－１）的云芝糖肽（ＰＳＰ）对小鼠的痛阈、耐力和免疫功能的影响。方法：用不同剂量的ＰＳＰ给小鼠连续７ｄ灌胃之后，测定其痛阈（热板法）、游泳耐力和Ｔ淋巴细胞增殖。结果：１ｇ·ｋｇ－１剂量的ＰＳＰ连续灌胃能显著地提高痛阈，显著地增强游泳耐力，但对Ｔ淋巴细胞增殖未见明显影响。大剂量（５～８ｇ·ｋｇ－１）的ＰＳＰ连续灌胃，不仅不能进一步提高镇痛效应和游泳耐力，相反，镇痛效应、耐力和Ｔ淋巴细胞增殖都有所下降。结论：５～８ｇ·ｋｇ－１大剂量ＰＳＰ的长期应用，有可能给正常小鼠带来负面影响。     

3,4,5-三甲氧基苯甲酸-8-(二乙胺基)-辛酯对大鼠脑血流及其自动调节功能的影响

用激光多谱勒血流仪连续测量脑血流量（ＣＢＦ），观察３，４，５－三甲氧基苯甲酸－８－（二乙胺基）－辛酯（ＴＭＢ－８）对麻醉大鼠ＣＢＦ及脑血流自动调节功能的影响．结果表明，ＴＭＢ－８０．５，１．０和２．０ｍｇ·ｋｇ－１呈剂量依赖性地增加ＣＢＦ５％，２０％和３４％．其中仅２．０ｍｇ·ｋｇ－１组使平均动脉压（ＭＡＢＰ）降低６％．而尼莫地平（Ｎｉｍ）０．０１ｍｇ·ｋｇ－１在使ＣＢＦ增加２１％的同时，使ＭＡＢＰ降低了２７％．麻醉大鼠脑血流自动调节的ＭＡＢＰ低限是５．３ｋＰａ．在ＭＡＢＰ４．０ｋＰａ时ＴＭＢ－８２．０ｍｇ·ｋｇ－１能增加脑血流自动调节能力，而Ｎｉｍ０．０１ｍｇ·ｋｇ－１则无明显作用．提示ＴＭＢ－８增加ＣＢＦ和增强脑血流自动调节能力是其抗脑缺血作用的机理之一．     

Attenuation of myocardial injury due to oxygen free radicals(OFR) by pretreatment with OFR or calcitonin gene-related peptide

目的：研究氧自由基（ＯＦＲ）及降钙素基因相关肽（ＣＧＲＰ）预处置对ＯＦＲ所致离体大鼠心脏损伤的拮抗作用．方法：Ｌａｎｇｅｎｄｏｒｆ法灌流心脏，电解ＫＨ液产生ＯＦＲ．结果：ＣＧＲＰ或ＯＦＲ预处置减轻ＯＦＲ所致心脏收缩功能下降，冠脉流量减少和肌酸激酶（ＣＫ）释放增加．蛋白激酶Ｃ（ＰＫＣ）抑制剂Ｈ７可取消ＯＦＲ预处置的心脏保护作用（对照组，ＯＦＲ损伤组，ＯＦＲ预处置组，Ｈ７加ＯＦＲ预处置组及Ｈ７组的ＣＫ释放量分别是１１０±７，２１５±２３，１６９±１４，２４０±３０，１１３±１９Ｕ·Ｌ－１）．结论：ＯＦＲ或ＣＧＲＰ预处置对ＯＦＲ所致心肌损伤具有拮抗作用，该作用与ＰＫＣ激活有关．     

痛稳素碳末端八肽翻转孤啡肽对抗吗啡镇痛的作用

目的　观察痛稳素碳末端八肽在小鼠脑内对孤啡肽对抗吗啡的镇痛作用的影响。方法　固相多肽合成法合成了痛稳素碳末端八肽 ,用辐射热甩尾法测定痛阈 ,观察 (1)小鼠脑室注射 (icv)孤啡肽对吗啡镇痛作用的影响 ;(2 )小鼠脑室注射 (icv)痛稳素碳末端八肽对小鼠基础痛阈的影响 ;(3)小鼠脑室联合注射 (icv)痛稳素碳末端八肽和孤啡肽对吗啡镇痛作用的影响。结果　孤啡肽可对抗吗啡的镇痛作用 ;痛稳素碳末端八肽本身不影响小鼠的基础痛阈 ,但可逆转孤啡肽对抗吗啡的镇痛作用。结论　痛稳素碳末端八肽在脊髓以上水平可以逆转孤啡肽对抗吗啡的镇痛作用     

Functional blockade of opioid analgesia by orphanin FQ/nociceptin

Orphanin FQ/nociceptin (OFQ/N) is a recently identified neuropeptide with high affinity for the orphan opioid receptor. OFQ/N blocked morphine analgesia in mice in a dose-dependent manner, as well as the analgesic actions of [D-Pen2, D-Pen5]enkephalin (DPDPE), morphine-6 beta-glucuronide, trans-3,4-dichloro-N-[2-(1-pyrrolindinyl)-cyclohexyl]-benzeneac eta mide, methane sulfonate hydrate (U50,488H) and naloxone benzoylhydrazone. These actions are anti-analgesic, because OFQ/N also blocked clonidine analgesia and OFQ/N was inactive against the inhibition of gastrointestinal transit by morphine. Although OFQ/N was quite potent in these paradigms, two truncated forms, OFQ/N(1-11) and OFQ/N(1-7), were inactive. An antisense oligodeoxynucleotide targeting the first coding exon of KOR-3, the mouse homolog of the orphan opioid receptor, effectively prevented the anti-opioid actions of OFQ/N, confirming the importance of the orphan opioid receptor in this action.     

The roles of nerve growth factor and cholecystokinin in the enhancement of morphine analgesia in a rodent model of central nervous system inflammation

Animal models of inflammatory pain are characterized by the release of inflammatory mediators such as cytokines and neurotrophic factors, and enhanced analgesic sensitivity to opioids. In this study, we examine the mechanisms underlying this effect, in particular the roles of cholecystokinin (CCK) and nerve growth factor (NGF), in an animal model of central nervous system (CNS) inflammation induced by spinal administration of lipopolysaccharide (LPS). Although spinal administration of LY-225910 (25 ng), a CCK-B antagonist, enhanced morphine analgesia in naïve rats, it was unable to do so in LPS-treated animals. Conversely, spinal CCK-8S administration (1 ng) decreased morphine analgesia in LPS-treated rats, but not in naïve animals. Further, spinal anti-NGF (3 μg) was able to reduce morphine analgesia in LPS-treated rats, but not in naïve animals, an effect that was reversed by spinal administration of LY-225910. While CCK-8S concentration was increased in spinal cord extracts of LPS animals as compared to controls, morphine-induced spinal CCK release in the extracellular space, as measured by in-vivo spinal cord microdialysis was inhibited in LPS animals as compared to controls, and this was reversed by anti-NGF pretreatment. Finally, chronic spinal administration of β-NGF (7 μg/day) for 7 days enhanced spinal morphine analgesia, possibly by mimicking a CNS inflammatory state. We suggest that in intrathecally LPS-treated rats, spinal CCK release is altered resulting in enhanced morphine analgesia, and that this mechanism may be regulated to an important extent by NGF.     

Morphine-induced analgesia in the rat paw pressure test is blocked by CCK and enhanced by the CCK antagonist MK-329

The effects of cholecystokinin octapeptide sulphated (CCK) and the potent CCK antagonist MK-329 (L-364, 718) on analgesia induced by morphine in the paw pressure test in the rat were examined. Both CCK (4-16 micrograms/kg) and MK-329 (0.1-8.0 mg/kg) had no significant effect on thresholds for pain when given alone, whereas morphine (2-16 mg/kg) induced dose-dependent analgesia. Cholecystokinin (4-16 micrograms/kg) abolished the analgesia induced by 8 mg/kg morphine. In contrast, doses of 1 and 2 mg/kg MK-329 enhanced the analgesia induced by 8 and 4 mg/kg morphine, respectively. The present data are consistent with previous reports that CCK blocks, and CCK antagonists enhance, opiate-induced analgesia in response to thermal pain stimuli. In addition, the results show that CCK/opiate interactions extend to mechanical pain stimuli. Recent ligand binding studies have shown that CCK receptors in the spinal cord of the rat (where CCK/opiate interactions are thought to occur) are predominantly of the CCK-B subtype. The drug MK-329 has a relatively weak (micromolar) affinity for CCK-B receptors and a high affinity (nanomolar) for CCK-A receptors. As relatively large doses (1-2 mg/kg) of MK-329 are required to enhance opiate-induced analgesia in the paw pressure test and tail flick test in rats it appears that CCK/opiate interactions in this species involve CCK-B receptors.     

Roles of periaqueductal gray and nucleus raphe magnus on analgesia induced by lappaconitine, N-deacetyllappaconitine and morphine

In the rat tail flick test, ip LA 6 mg/kg, icv DLA 60 micrograms and icv or with morphine 5 micrograms exhibited significant analgesia. But with either LA 40 micrograms or DLA 60 micrograms was inactive. Naloxone (4 micrograms icv) which antagonized morphine analgesia failed to alter the analgesia induced by LA and DLA. Microinjection of DLA 20 micrograms or morphine 5 micrograms into the periaqueductal gray (PAG) or nucleus raphe magnus (NRM) produced markedly analgesic activity. The effects of electrolytic and kainic acid (0.8 micrograms) lesions of the PAG and NRM on the analgesia elicited in the rat from ip LA, icv DLA and morphine were also evaluated. No change in baseline tail flick latency was observed following lesions of the PAG and NRM. But lesions of the PAG and NRM significantly attenuated the analgesia mediated by LA, DLA and morphine. These results suggest that supraspinal sites, especially the PAG and NRM, are involved in the analgesic action induced by LA, DLA and morphine.     

Nociceptin/orphanin FQ blocks the antinociception induced by mu, kappa and delta opioid agonists on the cold water tail-flick test

Nociceptin/orphanin FQ (N/OFQ), a 17-amino-acid peptide, is an endogenous agonist whose receptor is similar in sequence to mu, delta and kappa opioid receptors. It has been reported that N/OFQ can block antinociceptive effects induced by opioid receptor agonists in the radiant heat tail-flick test and warm water tail-withdrawal test. The present study was designed to see the effect of N/OFQ on antinociception induced by opioid receptor agonists in the cold water tail-flick (CWT) test, which measures a different type of pain. In adult male Sprague-Dawley (S-D) rats given subcutaneous (s.c.) injections of saline or morphine (8 mg/kg), intracerebroventricular (i.c.v.) injection of N/OFQ (18 microg) 15 min later produced a significant reversal of morphine antinociception (P<0.01, ANOVA followed by Duncan's test), compared to the corresponding saline control group. Saline (t=+15 min, i.c.v.) had no effect on s.c. morphine antinociception (P>0.01), compared to the corresponding saline control group. When the kappa opioid receptor agonist spiradoline (80 mg/kg, s.c.) was used instead of morphine, similar results were observed. In another series of experiments, it was found that i.c.v. injection of N/OFQ (18 microg) reversed the antinociception induced by i.c.v. injection of the selective mu opioid agonist PL017 (2 microg), delta opioid agonist DPDPE (50 ng) and kappa opioid agonist dynorphin (21.5 microg), respectively. These results indicate that N/OFQ may be an endogenous anti-opioid peptide in the brain of rats in the CWT test.     

Cholecystokinin and morphine-induced hypothermia.

The effects of cholecystokinin-8 sulfate (CCK-8), cholecystokinin-8 unsulfate (CCK-8U), cholecystokinin-4 (CCK-4), caerulein and morphine on mice core body temperature have been studied in the present work. Subcutaneous injection of different doses of caerulein (0.05, 0.1 and 0.5 mg/kg), CCK-8 (0.05, 0.1 and 0.25 mg/kg) and morphine (10, 20 and 30 mg/kg) induced hypothermia. CCK-8U and CCK-4 did not elicit any response. The hypothermic response induced by caerulein, a CCK-related decapeptide but not morphine was decreased by selective CCK(A) receptor antagonist MK-329. However, the hypothermia induced by morphine but not caerulein was reduced by opioid antagonist naloxone. When morphine plus caerulein was administered a higher hypothermia was induced. Pretreatment of animals with L-365 260, a selective CCK(B) receptor antagonist did not alter the hypothermia induced by the drugs. The response induced by combination of the both drugs was decreased by MK-329. Administration of CCK antagonists MK-329 and L-365 260 to mice did not exert any effect on temperature. It is concluded that the CCK(A) receptor mechanism may be involved in the hypothermic effect of CCK agonists or morphine, while opioid receptor mechanism is not involved in CCK receptor agonists' response.     

Enhancement of morphine analgesia and prevention of morphine tolerance in the rat by the cholecystokinin antagonist L-364,718

The potent and selective non-peptide cholecystokinin (CCK) antagonist L-364,718 (0.5-2.0 mg/kg s.c.) enhanced the analgesia induced by acute morphine treatment in the rat tail flick test. Chronic treatment with L-364,718 (1.0 mg/kg) prevented the development of tolerance to morphine analgesia (after a 6 day period of morphine treatment) but did not influence the onset of opioid dependence. Since L-364,718 is considerably more potent in inhibiting CCK binding to peripheral tissues than to brain membranes its interaction with morphine is surprising. The exact locus of this interaction, or whether it involves 'peripheral-type' (CCK-A) or 'central-type' (CCK-B) receptors is not known.