新抗胆碱药[~3H]三环哌酯对人脑M受体的作用

用放射配体受体结合试验法，研究了新化合物三环哌酯与人大脑皮质Ｍ受体的结合特性，并与ＱＮＢ作了比较。饱和实验结果显示，［３Ｈ］三环哌酯的结合参数与［３Ｈ］ＱＮＢ相近，两种配体的作用均符合单位点模型。竞争性抑制实验结果表明二者作用强度相当。［３Ｈ］三环哌酯的结合和解离速率常数均较［３Ｈ］ＱＮＢ大，且其与皮质Ｍ受体的解离受季铵酚的变构调节，结果提示，两种配体与Ｍ受体有一些不同的结合特性，在Ｍ受体研究中，［３Ｈ］三环哌酯可以作为［３Ｈ］ＱＮＢ的补充工具     

四氢巴马汀等异喹啉生物碱对突触体及囊泡摄取[3H]多巴胺的影响

本文报道四氢巴马汀(THP)等异喹啉生物碱对[³H]DA摄取的作用。突触体对[³H]DA的亲和力常数Km为0.23μmol。最大摄取速率Vmax为1.2 nmol/g(5 min)。d-THP,1-SPD和1-THP对突触体摄取[³H]DA均有抑制作用,其IC₅₀分别为0.44,2.24和18.5μmol。d-THP的作用比1-THP约强20倍。nomifensine,苯丙胺和氟哌啶醇亦能有效地抑制[³H]DA摄取(IC₍₅₀₎分别为0.05,0.27和3.18μmol)。动力学研究表明,d-THP和nomifensine为DA摄取的竞争性抑制剂。用低渗溶液处理溶胀的方法研究药物对递质贮存的作用发现,与利血平相似,d-THP显著降低贮存囊泡[³H]DA含量并使囊泡与突触体[³H]DA含量之比明显减小。实验结果表明,THP等能抑制突触体摄取,并直接作用于贮存囊泡抑制[³H]DA贮存,因此具有利血平样排空作用。     

新的高强度高选择性阿片μ受体激动剂[11C]-羟甲芬太尼的合成

羟甲芬太尼(I)是一个新的高强度高选择性阿片μ受体激动剂。本文用cis-A-N-[1-(2-羟基-2-苯乙基)-3-甲基-4-哌啶基]-苯胺(II)或cis-N-[1-(苯甲酰甲基)-3-甲基-4-哌啶基]-苯胺(III)作为前体合成了[¹¹C]-羟甲芬太尼,以便用正电子发射断层扫描(PET)来观察μ受体。通过水解cis-A-羟甲芬太尼(I)和cis-N-[1-(苯甲酰甲基)-3-甲基-4-哌啶]-N-苯基丙酰胺(cis-IV)的4-N-丙酰基分别获得II和III。溴乙烷的格氏试剂与回旋加速器产生的[¹¹C]-二氧化碳反应后继而直接加入邻苯二甲酸二酰氯和2,6-二叔丁基吡啶生成同位素标记中间体[¹¹C]-丙酰氯。[¹¹C]-丙酰氯与OH-前体(II)反应后再经HPLC分离纯化直接得[¹¹C]-羟甲芬太尼;[¹¹C]-丙酰氯与酮-前体(III)反应后,再用硼氢化钠甲醇溶液处理,然后进行HPLC分离纯化得[¹¹C]-羟甲芬太尼。两种方法均可获得ll.1～14.8GBq/μmol的特异性放射化学纯[¹¹C]-羟甲芬太尼。总共耗时为40～50min(EOB)。     

蝙蝠葛碱和粉防己碱对[3H]WEB 2086与体外牛脑前动脉平滑肌细胞结合的影响(英文)

用标记的血小板活化因子拮抗剂[³H]WEB 2086,在培养的牛脑前动脉平滑肌细胞上鉴定了血小板活化因子受体。结果表明在25℃时该细胞上存在两种与配基具有不同亲和力的受体结合位点,其中K_d-1=22.8±5.0 nmol·L^-1,K_d-2=186+20.5 nmol·L^-1;B_max-1=2.1±0.3 pmol/10⁴细胞,B_max-2=12.1±1-5 pmol/10⁶细胞。蝙蝠葛碱和粉防己碱均能抑制[³H]WEB2086与上述细胞的结合。     

北京鸭红细胞膜β肾上腺素受体放射配基结合测定法

本文以[³H]dihydroalprenolol([³H]DHA)为放射配基。对北京鸭红细胞(RBC)膜β受体进行了系统研究。结果表明,[³H]DHA与北京鸭RBC结合具有饱和性,肾上腺素能激动剂与[³H]DHA竞争结合的强弱顺序与它们的生物活性一致,提示结合有结构特异性和立体特异性,[³H]DHA与鸭RBC结合迅速、可逆。可见北京鸭RBC膜存在β受体,用于放射配基结合测定有取材方便,受体较丰富,膜蛋白得率高,[³H]DHA非特异结合低和易于保存等优点,可以代替火鸡RBC。     

K-Ⅱ和U-50488H对κ阿片受体亲和力的比较

3,4-二氯-N-甲基-N-[反式-2-(1-△³-吡咯啉基)环己基]苯乙酰胺(K-Ⅱ)是新合成的U-50488H类似物,其对小鼠的镇痛效应和对离体兔输精管的抑制作用均比U-50488H强。本文用放射受体结合试验方法对这两种化合物在富含x阿片受体的豚鼠小脑和大脑皮层前叶上的亲和力进行了比较,并求出这两种化合物的Ki值.结果表明K-Ⅱ对k阿片受体的亲和力比U-50488H强6～42倍。K-Ⅱ对阿片受体亚型选择性比较研究正在进行中。     

3,4-二氯-N-甲基-N-[反式-2-(1-△3-吡咯啉基)环己基]-苯乙酰胺盐酸盐的合成及其镇痛活性的研究

3, 4-Dichloro-N-methyl-N-[trans-2- (1-△³-pyrrolinyl)-cyclohexyl]-benzenacetamide hydrochloride (K-Ⅱ) was synthesized from N-methyl-7-azabicyclo [4.1.0] heptane by treatment with 2,5-dihydropyrrole to give N-[trans-2(1-△³-pyrrolinyl)-cyclohexyl]-N-methylamine which was amidated with 3,4-dichlorophenyl-acetic acid. K-Ⅱ is an analogue of U-50488 H(K-Ⅰ), a known kappa receptor agonist.The results of animal tests showed that K-Ⅱ is 3 times as potent as K-Ⅰ as an analgesic in the mouse hot plate test and 5 times in the mouse writhing test and that the affinity of K-Ⅱ for kappa receptor may be higher than that of K-Ⅰ. The general behavioural effects of these two agents are similar in mice.     

S-3(-三氟甲基)-6，7-双[4(-三氟甲基)苯基]-3，4-二氢喹啉-2(1H)-酮下调STAT3信号通路抑制人结直肠癌细胞生长的作用研究

目的 基于信号转导和转录活化因子3（STAT3）信号通路探讨三氟甲基化二氢喹喔啉酮类化合物S-3-（三氟甲基）-6,7-双［4-（三氟甲基）苯基］-3,4-二氢喹啉-2（1H）-酮（2o）对人结直肠癌细胞生长的抑制作用。方法 采用 MTT法检测三氟甲基化二氢喹喔啉酮类化合物 2b、2e、2f、2g、2k、2l、2m、2o、2q（20 μmo·L^-1）作 用 48 h 对 人 结 直 肠 癌 细 胞DLD-1 存活率的影响,检测化合物2o（0.5、1.0、2.0、5.0、7.5、10.0、12.5、15.0、17.5 μmo·L^-1）作用48 h对人结直肠癌细胞HCT116、RKO和DLD-1存活率的影响;克隆形成实验检测化合物2o（2.5、5.0、10.0 μmo·L^-1）对RKO、DLD-1、HCT116细胞增殖的影响;流式细胞术和 Hoechst染色检测化合物 2o 对细胞凋亡的影响;细胞划痕实验检测化合物 2o 对 DLD-1 和RKO 细胞迁移率的影响;Western blotting 法检测化合物 2o 对 RKO 细胞 p-STAT3、STAT3、骨髓白血病细胞分化蛋白（MCL）-1、生存素（Survivin）、B淋巴细胞瘤-2（Bcl-2）、Bcl-2相关X蛋白（Bax）蛋白表达水平的影响,检测化合物2o对白细胞介素-6（IL-6）刺激下p-STAT3、STAT3蛋白表达水平的影响。结果 化合物2o对DLD-1细胞的杀伤能力较其他化 合 物 强 ; 化 合 物 2o 对 HCT116、 RKO 和 DLD-1 细 胞 的 半 数 抑 制 浓 度 （IC₅₀） 分 别 为 （3.573±0.172）、（8.056±0.458）、（6.226±0.458）μmo·L^-1。与对照组比较,化合物2o明显降低了HCT116、RKO和DLD-1细胞的集落形成能力;显著降低DLD-1和RKO细胞迁移率（P＜0.01、0.001）;明显增加RKO、DLD-1细胞凋亡率;明显增加HCT116和RKO细胞核亮染比例;明显降低p-STAT3、MCL-1、Survivin、Bcl-2蛋白表达,明显升高Bax蛋白表达,对STAT3蛋白表达无明显影响。与对照组比较,IL-6刺激的模型组p-STAT3蛋白表达明显升高,STAT3蛋白表达无明显变化;与模型组比较,随着化合物2o浓度的升高,p-STAT3蛋白表达明显降低,STAT3蛋白表达无明显变化。结论 化合物2o可能通过下调STAT3信号通路发挥抗人结直肠癌作用。     

赛庚啶对大鼠心肌细胞膜[3H]-d-cis-硫氮卓酮结合部位的影响

苯并噻嗪类钙通道阻滞剂[³H]-d-cis-硫氮酮能以一种特异和可饱和的方式与离体大鼠心肌细胞膜结合,其K_D值和B_max分别为84nmol·L^-1和0.279pmol·mgprotein^-1。非标记的硫氮酮和赛庚啶均能完全抑制这种结合,其Ki值分别为102nmolL^-1和5.5umol·L^-1。上述结果证实在大鼠心肌细胞膜上也存有[³H]-硫氮酮受体,同时还提示赛马庚啶对心肌细胞膜的钙通道阻滞作用可能与作用于心肌细胞膜[³H]硫氮酮受体有关。     

Platelet 5-HT uptake sites in depression: three concurrent measures using [3H] imipramine and [3H] paroxetine

Platelet 5-HT uptake sites were measured in 40 depressed patients and 40 controls using [³H] imipramine binding, defined with desmethylimipramine (DMI) and Na⁺ dependence, and [³H] paroxetine binding. In control subjects the B_max of DMI defined [³H] imipramine binding was significantly higher than both Na⁺ dependent [³H] imipramine (by 30%) and [³H] paroxetine binding (by 22%). The B_max of Na⁺ dependent [³H] imipramine and [³H] paroxetine binding did not differ significantly. The K_d of Na⁺ dependent [³H] imipramine binding was significantly lower than the K_d of DMI defined [³H] imipramine binding. The binding of DMI defined and Na⁺ dependent [³H] imipramine and [³H] paroxetine did not differ significantly between depressed patients and controls in the total group, in those depressed patients who had never taken antidepressants or in those depressed patients who had been recently with-drawn from antidepressants. This study provides no support for the view that the number of platelet 5-HT uptake sites are reduced in depression.     

Binding studies with [3H]cis-methyldioxolane in different tissues

Summary Special conditions - tricine buffer containing Ca²⁺ and Mg²⁺, 22°C (TCM) — allow to label a much higher proportion of muscarinic receptors by [³H]cis-methyldioxolane (CD) than hitherto described (Vickroy et al. 1984 a). Taking the maximum number of binding sites, B _max, of [³H]QNB as 100%, B _max of [³H]CD amounts to 83% in the rat heart instead of the reported 17%, 33% in the cerebral cortex instead of 6%, 20% in hippocampus and 55% in pons/medulla. In the salivary glands specific binding was negligible. The affinities of a number of muscarinic agonists and antagonists to [³H]CD and [³H]QNB binding sites in different tissues of the rat are compared. Apparent affinities of agonists are much higher in the [³H]CD system, affinities of antagonists are slightly higher in the [³H]QNB system. In both assay systems receptors of heart and pons/ medulla membranes seem to have similar drug specificity. They differ somewhat from those in the cortex. Receptors in the salivary glands, however, seem to be completely different from those in the other three tissues. In the heart [³H]CD binding can be abolished almost completely by GppNHp. In the cortex about half of the [³H]CD binding is susceptible to GppNHp. The reduction of binding in the cortex is due to a change in B _max and not in the dissociation constant K _D. Competition of unlabelled pirenzepine with [³H]CD: In heart and pons/medulla only low affinity sites for pirenzepine (M₂-receptors) are labelled by [³H]CD. In regions rich in M₁ receptors like hippocampus (80% M₁ receptors) or cortex (65–70% M₁ receptors) the proportion of M₁ receptors labelled by [³H]CD is smaller than expected considering the concentration of M₁ receptors present in these tissues. Thus [³H]CD, under the conditions described in this paper, seems to label preferentially but not exclusively M₂ receptors in their agonist high affinity form. Send offprint requests to A. Closse at the above address     

Cholinergic modulation of [3H]dopamine release from dendrosomes of rat substantia nigra

Summary Dendrosomes prepared from substantia nigra are able to take up and release [³H]dopamine in a Ca²⁺-dependent manner. The V_max values of [³H]dopamine uptake in substantia nigra dendrosomes was about 5 times lower than that in caudate putamen synaptosomes. The pattern of the K⁺-dependency of the [³H]dopamine release in substantia nigra dendrosomes was significantly different from that found in caudate putamen synaptosomes. The release of [³H]dopamine evoked by 15 mmol/l KCl from superfused dendrosomes was increased in a concentration-dependent manner by acetylcholine. The maximal potentiation produced by acetylcholine was about 40%. The potentiation of [³H]dopamine release by 10 µmol/l acetylcholine was insensitive to mecamylamine but antagonized by atropine and by pirenzepine. The effects of acetylcholine on the release of [³H]acetylcholine from substantia nigra nerve endings was also studied. Exogenous acetylcholine added to the superfusion medium decreased in a concentration-dependent manner the release of acetylcholine. This effect was not antagonized by mecamylamine or pirenzepine but fully antagonized by atropine. The data suggest the existence, in the substantia nigra of the rat, of two distinct muscarinic receptor subtypes regulating respectively dopamine release from dopamine dendrites and acetylcholine release from cholinergic nerve terminals.Part of this work was presented at a satellite meeting of the 11th International Congress of Pharmacology: Dopamine '90 held in Como, Italy (July 1990) Send offprint requests to M. Raiteri at the above address     

[3H]MDL 100,907: a novel selective 5-HT2A receptor ligand

In studies using standard radioligands, unlabeled MDL 100,907 (R-(+)--(2,3-dimethoxyphenyl)-1-[2-(4-fluorophenyl)ethyl]-4-piperidinemethanol) has been shown to have a high degree of selectivity for the 5-HT_2A receptor. The present study was undertaken to investigate the receptor binding characteristics of [³H]MDL 100,907 in rat cortical homogenates. [³H]MDL 100,907 was found to reach equilibrium at 37°C after 15 min. Saturation experiments indicated binding to a single site with a K_D of 0.56 nM, Hill slope of 1.15, and a B_max of 512 fmol/mg protein. In parallel experiments with the standard 5-HT_2A receptor radioligand, [³H]ketanserin, with prazosin added to block ₁ receptors, a similar Hill slope and B_max was noted but a two-fold higher K_D was found. In competition binding studies using 0.5 nM [³H]MDL 100,907, some 19 standard ligands to various receptors including the 5HT_1A, D₂, ₁, and receptors resulted in estimated K_I values that were consistent with [³H]MDL 100,907 selectively binding to the 5-HT_2A receptor. A comparison of the K_I values for 17 standard 5-HT_2A receptor agonists and antagonists displacing [³H]MDL 100,907 versus [³H]ketanserin resulted in a highly significant linear correlation (R² = 0.96, P<0.001). Taken together these results suggest that [³H]MDL 100,907 is binding to the 5-HT_2A receptor with a sub-nanomolar affinity without the use of secondary blocking agents.     

小肠毒蕈碱型胆碱受体的多样性

从小鼠小肠收缩实验测得,乙酰胆碱引起纵,环肌收缩的50%有效浓度各为7～10^-5M和10^-4～10^-2M,阿托品的PA₂约为9和7。实验结果提示小肠上至少存在两种不同亲和性的毒蕈碱型胆碱受体,分别与纵、环肌收缩有关。又用Yamamura法将小肠全平滑肌层、纵肌层匀浆与³H-ONB做结合实验,测得解离常数KD值约为1 nm和15 nm的两种特异结合部位。