CCK-8对大鼠肺间质巨噬细胞cAMP-PKA信号通路的激活作用

目的探讨八肽胆囊收缩素(CCK-8)对大鼠肺间质巨噬细胞(PIMs)cAMP-PKA信号通路的激活作用。方法分离纯化大鼠PIMs,采用放射免疫分析法测定细胞内cAMP含量,放射激酶法测定PKA活性,受体拮抗剂的IC50值由对数-几率单位法求得。结果正常对照组大鼠静息状态下PIMscAMP含量和PKA活性分别为(2.04±0.13)nmol·g-1和(118.3±11.2)nmol·min-1·g-1。低浓度CCK-8[(10-12～10-10)mol·L-1]对细胞内cAMP含量和PKA活性没有影响(与正常对照组比较:P>0.05);高浓度CCK-8[(10-9～10-5)mol.L-1]可明显提高细胞内cAMP含量和PKA活性(与正常对照组比较:P<0.05)。10mg·L-1脂多糖(LPS)刺激大鼠PIMs,可明提高细胞内cAMP含量和PKA活性,分别为(5.15±0.12)nmol·g-1和(188.6±13.5)nmol·min-1·g-1。不同浓度的CCK-8与LPS共同孵育PIMs,细胞内cAMP含量和PKA活性的变化趋势与CCK-8作用于静息状态下大鼠PIMs的变化趋势完全相同。CCK受体拮抗剂丙谷胺、CR-1409、CR-2945可呈剂量依赖性地抑制CCK导致的cAMP含量的升高,它们的IC50值分别为(0.5×10-6、4.1×10-6、7.2×10-4)mol·L-1。丙谷胺、CR-1409、CR-2945也可明显减弱CCK-8所导致的PKA活性的升高;其中,丙谷胺的抑制作用最强,CR-1409次之,CR-2945的抑制作用最小。结论CCK-8可剂量依赖性地激活静息状态和LPS诱导的大鼠PIMscAMP-PKA信号转导途径,这可能是CCK抗炎作用的分子机制之一。CCK激活cAMP-PKA通路是通过CCK受体来实现的,且CCK-AR的作用比CCK-BR的作用更为明显。     

吗啡对原代培养大鼠海马神经元CCK受体mRNA表达的影响

目的探讨原代培养大鼠海马神经元上胆囊收缩素(cholecystokinin,CCK)受体CCK-AR及CCK-BR mRNA表达及吗啡对其表达的影响。方法采用新生大鼠海马神经元无血清原代培养技术,用吗啡(100μmol·L-1培养基)孵育3,6,12,18,24,36,48,72h,以及采用不同浓度吗啡(10,100,150μmol·L-1)孵育6、30h后,RT-PCR及测序方法观察CCK-AR及CCK-BR mRNA表达及吗啡对其表达的影响。结果RT-PCR结果显示,CCK-AR和CCK-BR mRNA在原代大鼠海马神经元上均有表达;CCK-AR mRNA RT-PCR扩增产物为218bp,CCK-BR mRNA RT-PCR扩增产物为444bp,经测序证实结果的可靠性;CCK-BR mRNA的表达量明显高于CCK-AR。吗啡作用后可使2种CCK受体mRNA表达上调。吗啡浓度及作用时间的不同对CCK-AR和CCK-BRmRNA表达的影响不同。结论原代大鼠海马神经元上有CCK-AR和CCK-BR,以CCK-BR为主;吗啡可使2种CCK受体mRNA表达上调。     

云芝多糖B对大鼠单核细胞趋化蛋白—1基因表达的影响

目的:探究野生云芝多糖水溶性新组分CVPS-B对大鼠脾细胞单核细胞趋化蛋白-1(MCP-1)基因表达的影响.方法:以β-actin为内标准物,用逆转录聚合酶链式反应(RT-PCR)检测CVPS-B分别对正常情况下以及脂多糖(LPS)诱导下大鼠脾细胞MCP-I基因表达的影响,并对RT-PCR产物进行测序,以证实其特异性.结果:(1)正常情况下大鼠脾细胞MCP-1 mRNA的表达(MCP-1/β-actin的比值)生理盐水对照组为1.4±0.3;CVPS-B三个剂量组(10、30和50mg·kg~(-1)·d~(-1),ip,连续4d)分别为:1.6±0.4、1.7±0.5和1.5±0.4,后三组与对照组无显著差异(P>0.05);(2)大鼠腹腔给药LPS(10μg·kg~(-1)可使脾细胞MCP-1 mRNA的表达增加114％.(3)CVPS-B4个剂量组(5、10、30和50mg·kg~(-1)·d~(-1),ip,连续4d)可使LPS(10μg·kg~(-1),ip)诱导的脾细胞MCP-1 mRNA的表达分别减低51％,70％,84％和99％(n=6).结论:CVPS-B可预防性抑制LPS对大鼠脾细胞MCP-1基因表达的诱导作用,且呈剂量依赖性,但对正常情况下大鼠脾细胞MCP-1 mRNA的表达则无明显影响.     

Effect of cholecystokinin octapeptide on diacylglycerol-PKC signaling pathway in rat pulmonary interstitial macrophages stimulated by lipopolysaccharide

AIM: To investigate the effect of cholecystokinin octapeptide (CCK-8) on the diacylglycerol-protein kinase C (DAG-PKC) signaling pathway in rat pulmonary interstitial macrophages (PIM) stimulated by lipopolysaccaride (LPS). METHODS: The PIM from rat lung tissues were isolated using the collagenase digestion method combined with alveolar lavage and pulmonary vessel perfusion. DAG content and PKC activity were measured by radioenzymatic assay. The translocation of PKCzeta was determined by semi-quantitative immunoblot analysis. RESULTS: CCK-8, at high concentrations (1 x 10(-6) - 1 x 10(-5) mol/L), decreased DAG content and inhibited PKC activity and PKCzeta translocation compared with that in rat resting PIM of a control group (P< 0.01). LPS increased DAG content, and promoted PKC activity and PKCzeta translocation (P< 0.01). CCK-8 decreased LPS-induced DAG content and inhibited LPS-induced PKC activity and PKCzeta translocation significantly at 1 x 10(-8) - 1 x 10(-5) mol/L (P< 0.01). This inhibitory effect of CCK-8 could be abrogated partly by proglumide (non-selective CCK receptor antagonist), CR-1409 (selective CCK-A receptor antagonist), and CR-2945 (selective CCK-B receptor antagonist) in a concentration-dependent manner (P< 0.01). CONCLUSION: CCK-8 was a negative modulator of the DAG-PKC signaling pathway in rat resting PIM, which is very important for maintaining body homeostasis. It significantly inhibited LPS-induced DAG content, PKC activity and PKCzeta translocation in a concentration-dependent manner. The CCK receptor, especially the CCK-A receptor, might play a major role in this process.     

CCK-8抗炎作用中DAG-PKC信号通路对cAMP-PKA信号通路的影响

目的探讨CCK-8抗炎作用中DAG-PKC信号通路对cAMP-PKA信号通路的影响。方法分离纯化大鼠PIMs,分别用LPS、CCK、LPS+CCK、PMA、SC-3088、LPS+PMA、LPS+SC-3088、CCK+PMA、CCK+SC-3088、LPS+CCK+PMA、LPS+CCK+SC-3088孵育一定时间,采用125I-cAMP放射免疫分析法测定细胞内cAMP含量,用放射激酶法测定PKA活性。结果单独应用PMA和SC-3088孵育大鼠PIMs,细胞内cAMP含量和PKA活性与正常对照组相比无明显变化(P>0.05)。PMA可升高LPS作用下的细胞内cAMP含量和PKA活性(P<0.01),SC-3088则可使LPS作用下的细胞内cAMP含量和PKA活性降低(P<0.01)。分别应用PMA、SC-3088与CCK共同孵育,则CCK+PMA组细胞内cAMP含量和PKA活性高于单独应用CCK组(P<0.01),CCK+SC-3088组则降低(P<0.01)。与LPS+CCK组相比,PMA+LPS+CCK组细胞内cAMP含量和PKA活性升高(P<0.01),而SC-3088+LPS+CCK组细胞内cAMP含量和PKA活性降低(P<0.01)。结论在LPS诱导的大鼠PIMs,CCK-8可通过激活cAMP-PKA信号通路发挥抗炎作用;DAG-PKC信号通路的活化对cAMP-PKA信号通路有正性调节作用。     

八肽胆囊收缩素对[~3H]埃托啡与大鼠脑阿片受体结合的抑制作用

本实验观察了CCK—8对[~3H]Et与大鼠脑阿片受体结合的影响.含硫CCK—8能抑制[~3H]Et与高亲和位点的结合,使K_D值增大(P<0.001),B_(max)减小(P<0.01),在10 fmol/L～Lμmol/L范围内呈量效关系.但对低亲和位点的结合没有影响.无硫CCK—8仅对[~3H]Et高亲和位点的K_D值有较小程度的增大(P<0.05),不影响B_(max)值.CCK—8(10 nmol/L)抑制[~3H]Et与阿片受体结合的作用能被CCK受体拮抗剂谷丙酰胺(1μmol/L)所阻断.结果提示,CCK—8可能通过激活CCK受体发挥对阿片受体的抑制作用。     

3，4—二苯基—3—吡咯啉—2—酮衍生物对小鼠腹腔巨噬细胞环氧酶1和2的抑制作用

目的:建立腹腔巨噬细胞模型评价化合物对环氧酶1和2的抑制作用.方法:放免法测定calcimycin、脂多糖刺激细胞将内源性花生四烯酸转化为6-keto-PGF_(1α)或PGE_2的量.GAPDH和环氧酶1/2的RNA用RT-PCR测定.结果:Rofecoxib选择性抑制脂多糖诱导的PGE_2合成,IC_(50)为(4.7±0.5)nmol/L,而抑制calcimycin诱导的6-keto-PGF_(1α)合成最大抑制率为17.3％.吲哚美辛对环氧酶1和2的IC_(50)分别为(4.7±1.1)nmol/L和(7.1±1.2)nmol/L.17个化合物中,系列Ⅱ化合物的活性与rofecoxib相当.磺酰胺基和内酰胺环的相对位置对抑制环氧酶2的活性很重要.结论:模型适用于药物设计的体外评价.3,4-二苯基-3-吡咯啉-2-酮衍生物有望成为新的环氧酶2选择性抑制剂.     

银杏内酯B对脂多糖刺激的小鼠腹腔巨噬细胞TNFα生成及大鼠胸腔多形核白细胞NF-κB活化的影响

目的研究银杏内酯B对脂多糖刺激的小鼠腹腔巨噬细胞TNFα生成及大鼠胸腔多形核白细胞NF-κB活化的影响。方法用L929细胞结晶紫染色法检测TNFα的含量，用电泳迁移率改变检测法检测NF-κB的结合活性。结果1和10 μmol·L^-1银杏内酯B能够显著抑制LPS刺激的小鼠腹腔巨噬细胞TNFα的生成，其IC₅₀为0.26 μmol·L^-1；1 mg·L^-1 LPS和1 nmol·L^-1 PAF均可活化大鼠胸腔多形核白细胞NF-κB；银杏内酯B能够抑制LPS或 PAF刺激的NF-κB活化。结论银杏内酯B能够抑制LPS刺激的小鼠腹腔巨噬细胞TNFα生成及大鼠胸腔多形核白细胞NF-κB的活化。PAF参与LPS激活NF-κB的过程。     

Imrecoxib： a novel and selective cyclooxygenase 2 inhibitor with anti-inflammatory effect

INTRODUCTION Cyclooxygenase (COX) is a rate-limiting enzymefor prostaglandin synthesis. Three isotypes of COXs(COX-1, COX-2, and COX-3) have been identified[1-2],though COX-3 activityinhuman has not beenconfirmed[3].COX-1 isconstitutivelyinvolved in actions suchas plate-let activation, gastrointestinal protection and kidneyfunction. COX-2 is primarilyproduced in response totissue damage andisinvolved in inflammatoryresponses.Traditional non-steroidal anti-inflammatory drugs…     

Single amino acid substitution of serine82 to asparagine in first intracellular loop of human cholecystokinin (CCK)-B receptor confers full cyclic AMP responses to CCK and gastrin

To understand molecular basis of Gs coupling to cholecystokinin (CCK)-A and CCK-B receptor subtypes, we examined cAMP responses in three sets of human CCK receptor mutants expressed in human embryonic kidney (HEK)293 cells. Single or double substitutions of the four nonconserved amino acids in the first intracellular loop of the CCK-BR were made with their CCK-AR counterparts to determine which residues are critical in Gs coupling. Single substitution of Ser82 to Asn, produced maximal cAMP responses comparable with the chimeric CCK-BR containing the entire first intracellular loop of the CCK-AR. Two other single substitutions, Leu81 to Arg and Leu85 to Met, produced significant but smaller cAMP responses. Ser82 was further changed into Asp, Thr, or Ala to determine the specificity of this position in Gs coupling by the CCK-BR. Replacements of Ser to Asp or Thr showed significant cAMP increases but the stimulatory effects were smaller than Ser to Asn, whereas Ser to Ala did not enhance any cAMP response to either CCK or gastrin. Finally, CCK-AR reverse mutants were studied to compare them with their corresponding CCK-BR mutants that showed increased cAMP responses. Substitution of CCK-AR residue Arg68 to Leu resulted in a complete loss of cAMP response, whereas Asn69 to Ser or Met72 to Leu showed markedly diminished cAMP responses. These data identify that specific residues in the first intracellular loop of both CCK receptor subtypes are critical for Gs coupling. Substitution of a single residue Ser82 to Asn in the CCK-BR is sufficient to confer full cAMP responses to agonist stimulation.     

Effect of epristeride on expression of TGF-beta receptor in rat prostatic epithelial cells in vitro.

AIM: To assess the effect of epristeride on the expression of transforming growth factor beta type II receptor (TbetaR II) in rat prostatic epithelial cells in vitro. METHODS: RT-PCR and Western blot were used to quantitatively detect the mRNA and protein expressions of TbetaR II in rat prostatic epithelial cells treated or untreated with epristeride. Immunocytochemical staining method was used to qualitatively analyze the expression of TbetaR II protein. RESULTS: After treatment with epristeride 180 or 360 nmol/L, TbetaR II mRNA expression levels were 0.56 +/- 0.08 and 0.59 +/- 0.07, respectively, which were significantly up-regulated compared with control cells (0.38 +/- 0.04, P < 0.05); expression level of TbetaR II protein were 3163 +/- 920 and 6769 +/- 1941, respectively, which were also markedly up-regulated compared with control cells (536 +/- 240, P < 0.05). Immunostaining showed weak positive reaction in control cells, while strong staining of TbetaR II was found in epristeride-treated cells. CONCLUSION: Epristeride may up-regulate the expression of TbetaR II to induce apoptosis of prostatic epithelial cells.     

基因mdr1高表达多药耐药肿瘤细胞对力达霉素的药物敏感性

目的利用经药物诱导获得的mdr1基因高表达细胞株以及通过mdr1基因转染建立的稳定高表达细胞株，研究多药耐药肿瘤细胞对力达霉素(C-1027)的药物敏感性。方法构建mdr1重组真核表达质粒pcDNA3.1/mdr1，利用脂质体转染技术，获得mdr1高表达HepG2肝癌细胞。经RT-PCR、细胞荧光免疫化学及罗丹明外排实验，鉴定了细胞的mdr1表达水平和药物外排活性。MTT方法测定敏感细胞及相对应的多药耐药细胞对力达霉素等多种抗肿瘤药物的药物敏感性。结果mdr1稳定转染细胞株HepG2/mdr1、多药耐药KBv200细胞和MCF-7/ADR细胞对力达霉素的IC₅₀值分别为(0.020±0.011) nmol·L^-1，(0.24±0.20) nmol·L^-1和(0.028±0.011) nmol·L^-1。相对于各自的敏感细胞，多药耐药细胞HepG2/mdr1，KBv200和MCF-7/ADR对力达霉素的抗药倍数分别是1.3，6.8和1.6倍，对阿霉素的抗药倍数分别是8.8， 37.2和181.3倍，对紫杉醇的抗药倍数分别是40.3， 336.8和49.2倍。结论 mdr1高表达的多药耐药肿瘤细胞对力达霉素仍高度敏感，未表现出抗药性。     

Vasodilatory effect of adrenomedullin in mouse aorta

Human adrenomedullin (AM) and human calcitonin gene-related peptide (CGRP) produced a concentration-dependent relaxation in mouse aorta, precontracted with noradrenaline. EC(50) values for AM and CGRP were 9.8 +/- 2.4 and 4.2 +/- 0.1 nmol/l, respectively. AM-mediated vasorelaxation was partially (3-fold) shifted by AM(22-52), the C-terminal AM fragment, but not by CGRP(8-37), a selective CGRP1 antagonist. Both AM(22-52) and CGRP(8-37) failed to inhibit CGRP-mediated vasorelaxation of mouse aorta rings. Binding of rat [(125)I]AM to these membranes was specific. Both human AM and AM(22-52) displaced rat [(125)I]AM binding in a concentration-dependent manner with IC(50) values of 12.0 +/- 4 and 19.4 +/- 8 nmol/l, respectively. In contrast, both human CGRP and CGRP(8-37) were weak in displacing [(125)I]AM binding. Very little specific binding was observed with [(125)I]CGRP. In conclusion, the data presented here demonstrate that the mouse aorta displays AM receptors that mediate vasorelaxation.     

N-n-alkylnicotinium analogs, a novel class of antagonists at α4β2* Nicotinic acetylcholine receptors: Inhibition of S(-)-nicotine-evoked 86Rb+Efflux from rat thalamic synaptosomes

Pyridine N-n-alkylation of S(-)-nicotine (NIC) affords N-n-alkylnicotinium analogs, previously shown to competitively inhibit [(3)H]NIC binding and interact with alpha4beta2* nicotinic receptors (nAChRs). The present study determined the ability of the analogs to inhibit NIC-evoked (86)Rb(+) efflux from rat thalamic synaptosomes to assess functional interaction with alpha4beta2* nAChRs. In a concentration-dependent manner, NIC evoked (86)Rb(+) efflux (EC(50) = 170 nmol/L). Analog-induced inhibition of NIC-evoked (86)Rb(+) efflux varied over a approximately 450-fold range. Analogs with long n-alkyl chain lengths (C(9)-C(12)) inhibited efflux in the low nmol/L range (IC(50) = 9-20 nmol/L), similar to dihydro-beta-erythroidine (IC(50) = 19 nmol/L). Compounds with shorter n-alkyl chain lengths (C(1)-C(8)) produced inhibition in the low micromol/L range (IC(50) = 3-12 micromol/L). C(10) and C(12) analogs completely inhibited NIC-evoked efflux, whereas C(1-9) analogs produced maximal inhibition of only 10% to 60%. While the C(10) analog N-n-decylnicotinium iodide (NDNI) did not produce significant inhibition of NIC-evoked dopamine release in previously reported studies, NDNI possesses high affinity for [(3)H]NIC binding sites (K(i) = 90 nmol/L) and is a potent and efficacious inhibitor of NIC-evoked (86)Rb(+) efflux as demonstrated in the current studies. Thus, NDNI is a competitive, selective antagonist at alpha4beta2* nAChRs.     

艾拉莫德对脂多糖激活大鼠肺泡巨噬细胞系TNFα产生及NF-κB活性的抑制作用

目的研究非甾体抗炎药艾拉莫德(T-614)对脂多糖(LPS)刺激的大鼠肺泡巨噬细胞系(NR8383)前炎症反应因子TNFα基因表达、蛋白合成的影响及其对核因子κB(NF-κB)的作用。方法体外培养NR8383经T-614(13.4，26.7及53.4 μmol·L^-1)处理，LPS刺激后应用酶联免疫吸附法(ELISA)检测细胞上清液中TNFα的水平，半定量逆转录聚合酶链式反应(RT-PCR)检测TNFα mRNA水平，ELISA法检测NF-κB的活性。结果T-614对LPS诱导的NR8383细胞TNFα mRNA水平和蛋白水平的上调有显著抑制作用，对NF-κB的转录活性也有抑制作用。结论 T-614可能通过抑制LPS诱导的NR8383的NF-κB活性而降低TNFα的产生。     

Chlormethiazole: neurochemical actions at the gamma-aminobutyric acid receptor complex

Chlormethiazole has been extensively employed as a sedative/hypnotic and anticonvulsant for more than 25 years. While pharmacological and electrophysiological studies have implicated the GABAA receptor complex in these actions, neurochemical findings have not been consistent with this conclusion. We now present evidence that pharmacologically relevant concentrations of chlormethiazole perturb the GABAA receptor complex. Chlormethiazole was found to increase 36Cl- uptake into rat cortical synaptoneurosomes in a concentration-dependent (EC50 = 48 +/- 3 microM; Emax = 8.9 +/- 0.8 nmol Cl-/mg protein per 5 s), picrotoxin-sensitive fashion. Chlormethiazole was also found to inhibit the binding of the 'cage' convulsant [35S]t-butylbicyclophosphorothionate to rat cortical membranes (IC50 = 58.6 +/- 0.6 microM) through an increase in the apparent KD of this radioligand. Moreover, at these concentrations chlormethiazole did not affect pentobarbital-enhanced [3H]flunitrazepam binding, but inhibited [3H]flunitrazepam binding with a low potency (IC50 = 1.6 +/- 0.2 mM). These findings provide neurochemical evidence that pharmacologically relevant concentrations of chlormethiazole can perturb the GABAA receptor complex, and suggest that this compound acts at a distinct locus from other sedative/hypnotics such as barbiturates, benzodiazepines and GABAmimetics.