吗啡镇痛耐受大鼠背根神经节κ阿片受体mRNA表达下调

目的:测定吗啡镇痛耐受大鼠背根神经节(DRG)中μ、δ、κ阿片受体的mRNA表达,进一步探索吗啡镇痛耐受中DRG阿片受体的作用。方法:健康成年♂Wistar大鼠20只,随机平均分为生理盐水对照组(NS组,n=10)和吗啡组(MS组,n=10)。采用盲法进行给药和疼痛行为测定。每天早、晚两次皮下注射(sc)药物,并于上午注射药物前、后30 min测定大鼠的热甩尾潜伏期(TFL)作为痛阈指标。NS组sc生理盐水1 ml.kg-1,MS组sc吗啡10mg.kg-1,连续注射7 d,d8早晨各组分别取5只处死,剩余大鼠(分别记为NSN亚组和MSN亚组)d8早晚两次sc纳洛酮0.4 mg.kg-1,并在d9处死。以TFL恢复至基础水平作为出现吗啡耐受的标准。大鼠处死后采用实时聚合酶链反应(real time PCR)方法检测L4-S4节段DRG中3种阿片受体的mRNA表达。结果:观察期两组大鼠的体重增加量差异无显著性,两组大鼠每天注射前测定的TFL差异无显著性。MS组大鼠在d1 sc吗啡后,TFL明显升高(P<0.05);d2注射吗啡后TFL达到最高,且明显高于d1用药后水平(P<0.01),随着吗啡用药次数增加,MS组用药后的TFL逐渐下降,d7应用吗啡后TFL降至基础水平(P>0.05),d8应用纳洛酮后,MSN亚组和NSN亚组的TFL并未发生显著性变化。采用real time PCR的2-ΔΔCt方法计算DRG中阿片受体的表达,MS组大鼠L4-S4节段DRG中μ受体和δ受体的mRNA表达与NS组差异无显著性,而κ受体的mRNA表达显著低于NS组;应用纳洛酮前、后,3种阿片受体的mRNA表达水平无明显改变。结论:DRG中κ受体的mRNA表达下调可能参与了吗啡镇痛耐受的形成。     

大黄素对P2X_(2/3)受体介导的三叉神经痛的作用研究

目的探究大黄素(emodin)对P2X2/3受体介导的三叉神经痛的作用影响。方法慢性压迫性损伤大鼠眶下神经(CCI-ION)建立大鼠三叉神经痛动物模型,应用von Frey细丝法测试机械痛敏阈值,观察大黄素对三叉神经痛(TN)大鼠机械痛敏阈值的影响。结合原位杂交、PT-PCR、免疫组织化学、免疫荧光、蛋白印迹等方法观察大鼠三叉神经节(TG)中P2X2/3受体的表达变化。结果术后14 d,Ⅲ组(TN模型组)和Ⅰ组(生理盐水对照组)、Ⅱ组(假手术组)、Ⅳ组(TN模型+大黄素干预组)相比较,大鼠手术侧眶下神经面部感觉区域机械痛敏阈值明显降低(P<0.01),大鼠TG中P2X2/3受体表达明显升高(P<0.01);Ⅰ、Ⅱ、Ⅳ组之间相比,大鼠手术侧眶下神经面部感觉区域机械痛敏阈值差异没有显著性(P>0.05);Ⅳ组TG中P2X2/3受体的表达较Ⅲ组低(P<0.01)。结论 P2X2/3受体涉及到三叉神经痛,大黄素对P2X2/3受体介导的三叉神经痛有一定抑制作用。     

INOSITOL-1,4,5-TRISPHOSPHATE [INS(1,4,5)P3] AND INS(1,4,5)P3 RECEPTOR CONCENTRATIONS IN HEART TISSUES

1. The isolation and culture of neonatal cardiomyocytes causes changes in the metabolism of inositol(1,4,5) trisphosphate (Ins(1,4,5)P₃) from primarily dephosphorylation in the intact tissue to a combination of phosphorylation and dephosphorylation in the cultured cells (Woodcock et al. 1992). 2. The content of Ins(1,4,5)P₃ was found to be higher in intact heart tissue than in the isolated neonatal cells (10.9 ± 1.3 and 0.5 ± 0.1 pmol/mg tissue, mean ± s.e.m., n= 4, P<0.002, respectively). 3. Despite this difference, Ins(1,4,5)P₃ receptors in intact tissue and in isolated cells were not different in terms of affinity (8.0 ± 1.7 and 10.9 ± 1.6 nmol/L, n= 3, respectively) or concentration (143.3 ± 20.5 and 91.2 ± 16.0 fmol/mg protein, n = 3, respectively). 4. Thus, while there appears to be a relationship between the tissue content of Ins(1,4,5)P₃ and its metabolism, no relationship to the properties of Ins(1,4,5)P₃ receptors could be demonstrated.     

P2X3受体在糖尿病神经病理性疼痛模型中的作用

目的观察P2X3受体在糖尿病神经病理性疼痛大鼠模型中的作用和意义。方法将40只SD大鼠随机分为造模组（n=30）和对照组（n=10）。按照60 mg/kg一次性腹腔注射链脲佐菌素（STZ）建立糖尿病大鼠模型。于STZ注射前和注射后第7、14、28天分别测定大鼠血糖、体重以及机械性痛阈的变化。造模组又均分为造模1周组、造模2周组、造模4周组三个亚组。在造模前及造模后1、2、4周利用von Frey hairs法测定大鼠机械痛阈,并通过Real-time法测定每个时间点大鼠脊髓背根神经节（DRG）P2X3受体的表达水平。结果肉眼观察糖尿病大鼠毛色暗淡,尾静脉采血点愈合缓慢,每日饮水,饮食,尿量显著增加,表现符合糖尿病大鼠的临床特征。各模型组血糖浓度均〉16.7 mmol/L,各模型组与对照组比较,差异有统计学意义（P〈0.01）。糖尿病大鼠体重较对照组同期大鼠增长缓慢,差异有统计学意义（P〈0.01）。造模组机械痛阈在造模1周后明显下降（P〈0.01）,并持续至4周（P〈0.01）;在造模1周后脊髓DRG内P2X3受体表达水平出现显著上调（P〈0.01）。大鼠P2X3受体表达水平变化与机械痛阈的下降存在相关性。结论糖尿病早期大鼠脊髓DRG P2X3受体表达即出现上调,并与疼痛相关,说明P2X3受体可能在糖尿病大鼠周围神经疼痛的发生及痛敏的维持阶段起重要作用。     

川芎嗪对大鼠坐骨神经慢性压迫性损伤L4/L5段背根神经节P2X3受体表达的影响

目的 探讨川芎嗪抑制P2X₃受体介导慢性神经病理痛的作用途径。方法 制备大鼠坐骨神经慢性压迫性损伤(CCI)神经病理痛模型，于d 2起ip川芎嗪100 mg·kg^-1，每天1次，共14 d。免疫组织化学法观察CCI大鼠L₄/L₅段背根神经节P2X₃受体的表达，全细胞膜片钳技术测定新鲜分离的L₄/L₅段背根神经节三磷酸腺苷（ATP）和α,β-亚甲基三磷酸腺苷（α,β-meATP）激活的电流。结果 与正常对照组比较，正常大鼠ip川芎嗪14 d，L₄/L₅段背根神经节P2X₃受体表达、ATP激活电流和α,β-meATP激活电流无明显变化，假手术组亦无明显变化。与假手术组比较，CCI模型组大鼠L₄/L₅段背根神经节P2X₃受体的表达、ATP和α,β-meATP激活电流明显增强。CCI大鼠ip川芎嗪14 d，L₄/L₅段背根神经节P2X₃受体表达、ATP和α,β-meATP激活电流较CCI模型组明显降低。结论 川芎嗪可抑制CCI大鼠L₄/L₅段背根神经节P2X₃受体的表达，从而对P2X₃受体介导的神经病理痛产生抑制作用。     

药物透过血脑屏障的3D-QSPR:H2受体拮抗剂的CoMFA和EVA分析

目的：药物透过血脑屏障是药代动力学的重要过程,H₂受体拮抗剂是作用于神经外周的抗溃疡药物,为避免该类药物透过血脑屏障损伤中枢神经,产生毒副作用,指导该类药物的设计与合成。方法和结果：选择了不依赖于实验参数的比较分子力场分析(CoMFA)方法和最近发展的本征值(EVA)方法,建立了有关的三维药代动力学性质(3D-QSPR)模型。CoMFA模型的统计参数为：交叉验证系数r²_cv=0.625,相关系数r2=0.893,F_3,17=47.270,标准偏差SE=0.254;EVA模型的统计参数为：交叉验证系数r²_cv=0.697,相关系数r²=0.922,F_3,17=67.766,标准偏差SE=0.203。结论：两种方法都能建立三维定量构效模型,EVA模型有更高的预测能力。     

EFFECTS OF 5HT2 RECEPTOR ANTAGONISTS ON RESPONSES TO POTASSIUM DEPOLARIZATION IN RAT ISOLATED AORTA

1. In order to determine whether 5HT₂ receptor antagonists can modify Ca²⁺ uptake via voltage-operated Ca²⁺ channel (VOC) in arterial smooth muscle, a comparative study of the effects of selected Ca²⁺ uptake blockers and 5HT₂ receptor antagonists on K⁺-induced contractions of rat aortic strip was undertaken. 2. The antagonist drugs studied included the Ca²⁺ uptake blockers verapamil, nifedipine, felodipine, diltiazem and cin-narizine, the 5HT₂ receptor antagonists cyproheptadine, ritanserin, mianserin, and ketanserin and the α₁-adrenoceptor antagonist prazosin. 3. With the notable exception of prazosin, each of these compounds diminished K⁺-induced aortic responses. 4. The following order of potencies (mean IC₅₀ values in mol/L) was established: felodipine (7.0 × 10^-11) >nifedipine (4.8 × 10^-9) >verapamil (5.5 × 10^-8) >cyproheptadine (6.2 × 10^-8) > diltiazem (4.1 × 10^-7) >cinnarizine (1.3 × 10^-6) >ritanserin (1.8 × 10^-6) >ketanserin (9.0 × 10^-6) > mianserin (2.0 × 10^-5). 5. The results suggest that antagonists of 5HT₂ receptors can modulate Ca²⁺ uptake via VOC in rat aorta.     

L5前根切断大鼠模型中背根神经节P2X3受体表达

目的：探讨L5前根切断（L5VRT）大鼠神经病理性疼痛模型背根神经节（DRG）P2X,受体表达。方法：雄性SD大鼠30只,随机分为5组（n=6）,A组（UVRT术后3d）、B组（L5VRT术后7d）、C组（L5VRT术后14d）、D组（UVRT术后21d）模型组和E组（假手术组）,E组仅行半椎板切除术暴露左侧脊髓,分别在各自的时间点灌注取材L5背根神经节,用免疫荧光染色方法观察P2X3受体表达的变化。结果：（1）L5前根切断手术后,大鼠从次日开始即能产生双足明显的机械痛敏,与E组相比差异有统计学意义（P〈0．05）,这种痛敏情况持续至少4周;（2）免疫荧光染色发现B组、C组及D组模型组同侧15DRG的P2X3受体的表达明显增加（P〈0．01）,B组、C组及D组模型组对侧L5DRG的P2X3受体的表达与E组相比变化不明显（P〉0．05）;A组模型组的双侧L5DRG的P2X3受体的表达与E组相比无明显变化（P〉0．05）。结论：（1）L5前根切断疼痛模型能产生双足明显的机械痛敏;（2）该模型背根神经节P2X3受体的表达变化可能参与其机械痛敏的机制。     

川芎嗪对P2X3受体介导的神经病理痛的作用研究

目的 探讨川芎嗪（tetramethylpyrazine，TMP）对P2X3受体介导的神经病理痛的作用。方法 建立大鼠坐骨神经慢性压迫性损伤（CCl）神经病理痛模型，应用von Frey细丝法和热辐射法测定机械缩足反射阈值（mechanical withdrawal threshold，MWT）和热缩足反射潜伏期（thermal withdrawallatency，TWL），观察川芎嗪对CCl大鼠MWT和TWL的影响。结合免疫组织化学方法观察大鼠L4／L5段脊髓P2X，受体的表达变化。结果术后14d，V组（CCl模型组）和Ⅰ组（生理盐水对照组）、Ⅱ组（TMP对照组）、Ⅲ组（假手术组）、Ⅳ组（CCl模型＋TMP治疗组）相比较大鼠后爪的机械和热痛敏阈值明显降低（P〈0．05），大鼠脊髓P2X，受体表达明显升高（P〈0．05）；Ⅰ、Ⅱ、Ⅲ、Ⅳ组之间相比大鼠后爪的机械和热痛敏阈值差异没有显著性（P〉0．05），大鼠脊髓P2X，受体表达差异没有显著性（P〉0.05）；Ⅳ组脊髓P2X，受体的表达较Ⅴ组低（P〈0．05）。结论 川芎嗪对P2X，受体介导的神经病理痛有抑制作用。     

L5前根切断大鼠模型中背根神经节P2X_3受体表达

目的:探讨L5前根切断(L5 VRT)大鼠神经病理性疼痛模型背根神经节(DRG)P2X3受体表达.方法:雄性SD大鼠30只,随机分为5组(n=6).A组(L5 VRT术后3 d)、B组(L5 VRT术后7 d)、C组(L5 VRT术后14 d)、D组(L5 VRT术后21 d)模型组和E组(假手术组),E组仅行半椎板切除术暴露左侧脊髓,分别在各自的时间点灌注取材L5背根神经节,用免疫荧光染色方法观察P2X3受体表达的变化.结果:(1)L5前根切断手术后,大鼠从次日开始即能产生双足明显的机械痛敏,与E组相比差异有统计学意义(P<0.05),这种痛敏情况持续至少4周;(2)免疫荧光染色发现B组、C组及D组模型组同侧L5 DRG的P2X3受体的表达明显增加(P<0.01),B组、C组及D组模型组对侧L5 DRG的P2X3受体的表达与E组相比变化不明显(P>0.05);A组模型组的双侧L5 DRG的P2X3受体的表达与E组相比无明显变化(P>0.05).结论:(1)L5前根切断疼痛模型能产生双足明显的机械痛敏;(2)该模型背根神经节P2X3受体的表达变化可能参与其机械痛敏的机制.     

POSSIBLE INVOLVEMENT OF MUSCARINIC M1 AND M3 RECEPTOR SUBTYPES MEDIATING VASODILATION IN ISOLATED, PERFUSED CANINE LINGUAL ARTERIES

1. Using the cannula insertion method, muscarinic receptor subtypes were analysed in isolated, perfused canine lingual arteries preconstricted with phenylephrine. 2. Both acetylcholine and McN-A-343 induced a profound vasodilation in a dose-related manner. Acetylcholine-induced dilations were approximately 1000-times more potent than McN-A-343-induced dilation. 3. Acetylcholine-induced dilations were abolished after removal of the endothelium by intraluminal treatment with 1 mg saponin. 4. Acetylcholine-induced dilations were markedly inhibited by an M₁/M₃ receptor antagonist, 4-DAMP. Moreover, they were slightly, but significantly, inhibited by an M₁ antagonist, pirenzepine, but never influenced by an M₂ antagonist, AF-DX 116. Mc-N-A-343-induced vasodilations were inhibited by both 4-DAMP or pirenzepine. 5. These results suggest that there are abundant functional M₃ and a few M₁ receptors in the canine lingual artery that mediate vasodilation and that this vasodilation is dependent on the presence of an intact endothelium.     

Pharmacological properties of P2X3-receptors present in neurones of the rat dorsal root ganglia

1. The electrophysiological actions of several agonists which may differentiate between P2X₁- and P2X₃-receptors were studied under concentration and voltage-clamp conditions in dissociated neurones of 1–4 day old rat dorsal root ganglia.
2. β,γ-Methylene-D-ATP (β,γ-me-D-ATP) (1–300 μM), diadenosine 5′,5′′′-P¹,P⁵-pentaphosphate (AP5A) (100 nM–300 μM), diadenosine 5′,5′′′-P¹,P⁴-tetraphosphate (AP4A) (300 nM–300 μM) and uridine 5′-triphosphate (UTP) (1 μM–1 mM) all activated concentration-dependent inward currents with a latency to onset of a few ms.
3. The concentration-response curves for β,γ-me-D-ATP and AP5A and ATP had similar maximum values, while that for AP4A had a lower maximum. The concentration-response curve to UTP was shallow and did not reach a maximum. β,γ-Methylene-L-ATP was virtually inactive. The rank order of agonist potency was ATP>AP5A≈amp;AP4A>β,γ-me-D-ATP>UTP>>β,γ-methylene-L-ATP.
4. The inward currents were inhibited by the P2-receptor antagonists suramin (100 μM) and pyridoxalphosphate-6-azophenyl-2′,4′-disulphonic acid (PPADS) (10 μM). PPADS also inhibited responses to ATP (800 nM) and α,β-methylene ATP (2 μM) in a concentration-dependent manner.
5. This study shows that β,γ-me-D-ATP, AP5A, AP4A and UTP all act via a suramin- and PPADS-sensitive P2X-receptor to evoke rapid, transient inward currents in dissociated neurones of rat dorsal root ganglia. The very low activity of β,γ-methylene-L-ATP suggests that the agonists were acting at the P2X₃-subtype to produce these effects.

     

川芎嗪对大鼠坐骨神经慢性压迫性损伤L4/L5段背根神经节P2X3受体表达的影响

目的探讨川芎嗪抑制P2X3受体介导慢性神经病理痛的作用途径。方法制备大鼠坐骨神经慢性压迫性损伤(CCI)神经病理痛模型,于d 2起ip川芎嗪100 m.gkg-1,每天1次,共14 d。免疫组织化学法观察CCI大鼠L4/L5段背根神经节P2X3受体的表达,全细胞膜片钳技术测定新鲜分离的L4/L5段背根神经节三磷酸腺苷(ATP)和α,β-亚甲基三磷酸腺苷(α,β-meATP)激活的电流。结果与正常对照组比较,正常大鼠ip川芎嗪14 d,L4/L5段背根神经节P2X3受体表达、ATP激活电流和α,β-meATP激活电流无明显变化,假手术组亦无明显变化。与假手术组比较,CCI模型组大鼠L4/L5段背根神经节P2X3受体的表达、ATP和α,β-meATP激活电流明显增强。CCI大鼠ip川芎嗪14 d,L4/L5段背根神经节P2X3受体表达、ATP和α,β-meATP激活电流较CCI模型组明显降低。结论川芎嗪可抑制CCI大鼠L4/L5段背根神经节P2X3受体的表达,从而对P2X3受体介导的神经病理痛产生抑制作用。     

基因检测指导P2Y12受体拮抗药个体化治疗的研究现状

本文综述基因检测指导P2Y₁₂受体拮抗药个体化治疗的研究进展,对细胞色素P450 2C19代谢型、药品说明书、临床指南、随机对照试验等相关资料进行综述,为读者了解相关领域提供参考。     

EFFECTS OF V2 RECEPTOR ACTIVITY ON THE PRESSOR RESPONSE TO VASOPRESSIN IN THE RAT

1. To determine the contribution of V1 and V2 receptor activity on the enhancement of reflex buffering of the pressor response to arginine-vasopressin (AVP), mean arterial pressure (MAP) and heart rate (HR) changes were examined in response to graded injections of phenylephrine, AVP, or Phe2Orn8OT, a potent, selective V1-receptor agonist in the absence and presence of Val4DArg8VP, a potent, selective V2-receptor agonist. 2. There were no significant differences in MAP responses to the V1 agonist in the absence and presence of the V2 agonist in either conscious intact or autonomic-blocked rats. 3. Autonomic blockade with methscopolamine and hexamethonium increased the pressor sensitivity to phenylephrine threefold. In contrast, the pressor sensitivities to AVP and Phe2Orn8OT were increased 14-fold and 11-fold, respectively, by autonomic blockade. 4. V2-receptor activity does not have any inherent vasocative action or synergistic vasoactive action with V1-receptor activity. 5. V2 receptors do not play a role in enhancing reflex buffering of the pressor response to AVP; V1 receptors are suggested to play the role.     

P2X2/3受体在大鼠眶下神经慢性压迫性损伤中表达水平的动态变化

目的探讨P2X2/3受体在三叉神经痛(TN)模型大鼠三叉神经节(TG)神经元内表达的动态变化及其作用。方法采用行为学观察、HE染色评价慢性压迫性损伤大鼠眶下神经模型造模结果,免疫组化方法测定每组TG神经元不同时期P2X2/3的表达情况。结果正常对照组P2X2/3在中、小直径神经元中有阳性表达;P2X2/3的表达量在手术侧组各时间段均明显高于正常对照组(P<0.05);假手术组术后早期,P2X2/3表达量明显高于对照组(P<0.05),晚期两者无明显差异;手术对侧组与假手术组相比,P2X2/3表达量在术后早期无明显差异,术后晚期明显增多(P<0.05)。结论TG神经元中P2X2/3参与了TN的诱发、痛觉传递过程,其中P2X2主要参与急性痛或炎性痛,而P2X3对急性痛及痛疼的维持都起重要作用;手术侧的痛觉神经传导对对侧TG产生了影响。     

BLOOD PRESSURE EFFECTS OF THROMBOXANE A2 BLOCKADE IN SPONTANEOUSLY HYPERTENSIVE RATS

1. The effects of CGS 22652, a thromboxane (Tx) A₂ synthase inhibitor and TxA₂ prostaglandin (PG) H2 receptor antagonist, on blood pressure (BP) were studied in conscious freely moving spontaneously hypertensive rats (SHR). 2. Three groups of 13 male SHR were subcutaneously infused from 5 to 11 weeks of age via osmotic minipumps with CGS 22652 at doses of 5 (SHRa) or 10 (SHRb) mg/ kg per 24 h or with the vehicle only (SHRc). A fourth group (SHRd, n= 13) was orally treated from 3 to 11 weeks of age with CGS 22652 (30 mg/kg) given by gavage once a day. 3. CGS 22652 dose-dependently reduced the age-related increase in systolic BP. The pressor response to noradrenaline (200 ng/kg, i.v.) but not to angiotensin I or II was slightly (P<0.05) diminished in 11 week old SHRb and SHRd compared to SHRc. Acute ganglionic blockade by trimethaphan (10 mg/kg, i.v.), as well as angiotensin converting enzyme inhibition by perindopril (2 mg/kg, i.v.) decreased BP to a similar extent in the four groups. After combined blockade of vasopressin receptors and of the autonomic nervous system and the administration of a direct vasodilator (hydralazine, 3 mg/kg, i.v.), the residual mean BP was identical in the four groups of rats. 4. Chronic treatment with CGS 22652 dose-dependently antagonized the TxA₂ PGH₂ receptors but did not modify the TxA₂ synthesis. The urinary sodium excretion did not differ between groups. 5. In conclusion, at the doses used, CGS 22652 given either orally or subcutaneously exhibited only TxA₂/PGH₂ receptor blocking properties in SHR. Chronic treatment modestly prevented the development of hypertension in SHR, probably through a decrease in the pressor effects of TxA₂ and of noradrenaline.