Effects of GABAA receptor ligands on noradrenaline concentration and β-adrenoceptor binding in mouse cerebral cortex

The present experiments investigated changes in -adrenoceptor binding and noradrenaline stores in mouse cerebral cortex after single treatments with drugs which bind to the GABA_A receptor but which attenuate the actions of GABA. Neither the GABA antagonist, securinine, nor the picrotoxin/Cl^– channel ligand, picrotoxin, affected noradrenaline levels or -adrenoceptor binding. However, both the benzodiazepine inverse agonist, DMCM, and pentylenetetrazole increased noradrenaline levels 24 h after injection. Only pentylenetetrazol modified -adrenoceptor binding: there was a significant increase in receptor number 4 days after injection, but a significant decrease after 7 days. The anxiogenic, proconvulsant drug, yohimbine, was without effect. The changes induced by DMCM and pentylenetetrazole do not seem to be related to the behavioural effects of these drugs or to their affinity for binding to benzodiazepine receptors. The possibility that these compounds have actions in addition to those at the GABA_A receptor is discussed.     

Conformational features responsible for the binding of cyclic analogues of enkephalin to opioid receptors

Models of μ- and δ-receptor-bound backbone conformations of enkephalin cyclic analogues containing Phe⁴ were determined by comparing geometrical similarity among the previously found low-energy, backbone structures of -enkephalinamide, -enkephalinamide, -enkephalin and -enkephalin. The present μ-receptor-bound conformation resembles a β-I bend in the peptide backbone centred on the Gly³-Phe⁴ region. Two slightly different models were found for the δ-receptor-bound conformation; both of them are more extended than the μ-receptor-bound conformation and include a γ-turn (or a γ-like turn) on the Gly³ residue. Energetically favourable rotamers of Tyr and Phc side chains were also determined for the μ- and δ-conformations. The present models of μ- and δ-conformations share geometrical similarity with the low-energy structures of Leu-enkephalin and the analogue.     

Plasma membrane-mediated nuclear uptake and chromatin binding of insulin in tumor cell lines

Analysis of different cellular fractions after incubation of SW 948 and SW 707 colorectal carcinoma cells or WM 266-4 melanoma cells with 125I-insulin revealed the nondegraded hormone in the chromatin of these cells. Nuclear 125I-insulin was bound to specific fragments of EcoRI-, HaeIII-, and HincII-digested chromatin. A 45-kDa chromatin protein species that binds 125I-insulin was identified. Actinomycin D and cycloheximide inhibited the insulin-stimulated expression of chromatin receptors. Uptake of 125I-insulin by isolated nuclei occurred only in the presence of plasma membranes. Thus, at least some effects of insulin on target cells can be explained by direct gene regulation instead of "second messenger" action.     

Cyclical use of tamoxifen and high-dose medroxyprogesterone acetate in advanced estrogen receptor positive breast cancer

Summary One-hundred and seventy patients with estrogen receptor positive (10 pmol/g protein) advanced breast cancer have been treated in a prospective randomized study either with continuous tamoxifen 30 mg × 1 daily (TAM), or with TAM 30 mg × 1 daily for 8 weeks alternating with medroxyprogesterone acetate 500 mg × 2 daily for 8 weeks (TAM/HD-MPA). The response rate was 62% in the group treated with cyclic TAM/HD-MPA versus 41% in the TAM alone group (p = 0.02). There was no significant difference in duration of remissions or survival.     

Expression and function of c-kit receptor in bone marrow mononuclear cells of patients with myelodysplastic syndromes

目的　了解骨髓增生异常综合征 (MDS)骨髓单个核细胞c kit受体的表达与功能。方法　采用免疫荧光方法测定c kit受体蛋白 (CD117)的表达 ;逆转录 聚合酶链反应方法测定c kitmRNA的表达 ;细胞培养检测c kit受体的功能。结果　CD117表达率正常人为 3 0 4 %± 1 4 9% ,MDS患者为 8 58%± 5 2 8% ,两者差异有显著性 (P <0 0 5) ;RA患者为 5 12 %± 2 13% ) ,RAEB RAEB t患者为 10 0 1%± 5 0 7% ,两者差异有显著性 (P <0 0 5) ;MDS继发白血病患者为 32 4 3%± 18 16 %。MDS患者c kit基因mRNA表达与CD117表达相一致。正常骨髓单个核细胞体外半固体培养 ,在加入造血干细胞因子、白细胞介素 3、红细胞生成素 (SCF IL 3 Epo)后形成的粒 巨噬细胞集落 (CFU GM)较仅加入IL 3 Epo显著增多 (P <0 0 5) ,红系爆式集落 (BFU E)数量极显著增多 ,且BFU E体积显著增大(P <0 0 1)。MDS患者在上述相同条件下CFU GM数量无明显变化 (P >0 0 5) ,与正常对照比较 ,CFU GM和BFU E数量均显著减少 (P <0 0 5)。结论　MDS患者骨髓单个核细胞CD117表达明显高于正常对照 ,且与病情进展相关 ;c kitmRNA表达与CD117表达相一致 ;MDS患者骨髓单个核细胞体外培养时 ,SCF协同IL 3、Epo促进造血干 祖细胞增殖分化能力较正常对照明     

Effect of ipratropium bromide on airway and pulmonary muscarinic receptors in a rat model of chronic obstructive pulmonary disease

Objective　To observe the level of muscarinic receptors in airway and lung tissues, and the effect of inhaled ipratropium bromide on these receptors in a rat model of chronic obstructive pulmonary disease (COPD). Methods　This model was developed by exposure of rats to 250 ppm SO2 gas, 5?h/d, 5d/wk, for a period of 7 wk. The COPD rats inhaled 0.025% aerosolized iratropium bromide for 20 min, 2 times daily, in an airtight chamber. Muscarinic receptors in airway and lung tissues of normal rats, ipratropium bromide-treated COPD rats and the recovering COPD rats were measured by the radio-ligand binding assay. Results　Airway/lung pathology and pulmonary function tests showed that chronic SO2 exposure caused pathophysiologic changes similar to those observed in human COPD. The density (0.038±0.011, pmol/mg protein) and affinity (Kd, 23±11 pmol/L) of muscarinic receptors in airway and lung tissues of COPD rats were not changed compared with those of normal control rats (0.030±0.008 and 29±19, respectively, P&gt;0.05). Densities of the muscarinic receptors were not changed after inhalation of ipratropium bromide for 5 days, but increased significantly after inhalation for 30 days, as compared with those of the untreated COPD rats. The muscarinic receptors returned the normal levels at day 6 after cessation of ipratropium bromide treatment. There were no differences among different groups of rats in equilibrium dissociation constants (Kd). Conclusion　A rat model of COPD with pathophysiologic changes similar to the human counterpart was developed using chronic SO2 exposure. There was no significant change in the number and function of muscarinic receptors in airway and lung tissues of the COPD rats, but upregulation of the muscarinic receptors was observed after long-term inhalation of ipratropium bromide.     

豚鼠视网膜组织M4受体的表达

目的 检测M4受体在豚鼠视网膜组织的表达及分布.方法 4周龄三色豚鼠21只,其中7只动物眼球制备石蜡切片,免疫组织化学染色法检测后极部视网膜组织M4受体表达与分布;其余动物分别提取眼视网膜组织RNA和蛋白质,逆转录聚和酶链反应(RT-PER)、蛋白质免疫印迹(Western blot)法检测M4受体mRNA和蛋白质表达.结果 免疫组织化学染色显示,M4受体分布于豚鼠视网膜RPE细胞层,光感受器细胞层、外核层、内核层,大多数神经节细胞,以及内从状层和内核层交界区;豚鼠视网膜组织表达M4受体mRNA,扩增产物约为221 bp,阴性对照未见扩增产物.免疫印迹显示,豚鼠视网膜组织表达明显的M4受体免疫反应活性,分子量约为38 000.阴性对照组无阳性表达条带.结论 豚鼠视网膜组织有M4受体蛋白表达.     

电针对大鼠胃粘膜胃泌素和EGFR表达及AgNOR的影响

目的 观察电针足三里穴对胃粘膜细胞受体表达及核增殖的影响。探讨针灸作用机制。方法 75只SD大鼠随机分段分为5线,在清醒状态下针刺实验,SABC法免疫组化染色观察胃粘膜细胞胃泌素（Gas)、表皮生长因子受体（EGFR）表达程度,AgNOR特染观察胃腺细胞增殖情况。结果 电针足三里穴胃粘膜EGFR阳性表达率73.3%,Gas表达率66.7%;电针三阴交对EGFR表达远景as表达率为46.7%;联合穴位组Gas,EGFR表达均达60.0%,AgNOR特染各组核内嗜银颗粒无明显差异。结论 电针足三里可提高胃粘膜细胞Gas和EGFR表达率。改变细胞分子结构。影响细胞功能,电针对胃粘膜细胞核增殖无影响。     

两类胃酸分泌抑制剂治疗急性消化性溃疡出血的比较研究

目的　比较抑酸药 H2 受体拮抗剂 (H2 A)与质子泵抑制剂 (PPI)对消化性溃疡出血的疗效 .方法　 130只 SD大鼠随机分成 6组 ,制备急性胃溃疡出血模型 ,以不同 p H值的缓冲液冲洗胃溃疡部位后记录其胃粘膜出血时间 (GMBT) .2 2 4例消化性溃疡急性出血患者 ,随机分 2组 ,2 4h内洛赛克组静滴 40 mg洛赛克 ,法莫替丁组静滴 40 mg法莫替丁 ,动态测定给药前 1h及给药后 2 4h胃内 p H值 . 3回顾性分析2 72例应用洛赛克 (4 0 m g静滴 ,1次· d- 1 )与 2 70例应用法莫替丁 (4 0 mg静滴 ,2次· d- 1 )的消化性溃疡出血患者手术率与死亡率 .结果　当 p H≥ 6 .0时大鼠 GMBT明显缩短 (P<0 .0 5 ) .胃内 p H值监测结果 ,用药后各组 p H>4.0 ,p H>6 .0的时间 ,洛赛克组比法莫替丁组显著延长 (P<0 .0 1) .洛赛克治疗组手术率比法莫替丁治疗组明显减低 (P<0 .0 5 ) ,而死亡率无显著差异 .结论　对急性消化性溃疡出血 ,质子泵抑制剂的抑酸止血效果明显高于 H2 受体拮抗剂     

雌激素β受体在成年雄性大鼠脑内的免疫组化定位研究

目的 为了研究雌激素作用于神经系统的机制,研究了近年发现的雌激素β受体免疫阳性物质在雌性大鼠脑内的分布。方法 应用免疫组化S－P法并结合硫酸镍铵增强显色技术。结果 ①免疫阳性物质主要位于神经元的细胞核内,部分细胞的核周质和突起内也有浅谈的着色;也有部分神经元仅仅胞浆呈阳性;②最强阳性信号见于前嗅核、大脑皮质、斜角带垂直部、小脑浦肯野细胞、上丘各部、动眼神经核、红核、蓝斑、三叉神经运动核以及斜方体内、外侧核;中等强度的染色见于斜角带水平部、终纹床核、视前内侧核、乳头体内侧核以及黑质;较弱的阳性细胞见于下丘脑核团、未定带、杏仁复合体的部分核团以及脑桥网状核后部;微弱的阳性信号见于隔外侧核、苍白球、嗅结节岛、海马。结论 雌激素β受体在成年大鼠脑组织内有广泛的分布,在脑组织内雌激素可能通过β受体这一新的信号途径发挥多种重要的调控作用。