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/10~4细胞,B_(max-2)=12.1±1-5 pmol/10~6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。     

山莨菪碱和蝙蝠葛碱对白三烯和PAF诱导的牛脑前动脉平滑肌细胞DNA合成的影响(英文)

白三烯和血小板活化因子在低于nmol浓度时就能刺激培养的牛脑前动脉平滑肌细胞的DNA合成,在10~(-7)mol/L时达最大刺激。LTB_4,LTD_4和PAF在10~(-7)mol/L时对上述细胞DNA合成的刺激率分别为32％,29％和77％。山莨菪碱和蝙蝠葛碱在10~(-7)～10~(-4)mol/L范围内呈剂量依赖性地抑制白三烯和血小板活化因子的上述作用。     

山莨菪碱和蝙蝠葛碱对白三烯和PAF诱导的牛脑前动脉平滑肌细胞DNA合成的影响(英文)

白三烯和血小板活化因子在低于nmol浓度时就能刺激培养的牛脑前动脉平滑肌细胞的DNA合成,在10^-7mol/L时达最大刺激。LTB₄,LTD₄和PAF在10^-7mol/L时对上述细胞DNA合成的刺激率分别为32%,29%和77%。山莨菪碱和蝙蝠葛碱在10^-7～10^-4mol/L范围内呈剂量依赖性地抑制白三烯和血小板活化因子的上述作用。     

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。     

粉防己碱和蝙蝠葛碱减低抗三尖杉酯碱的人白血病HL60细胞对阿霉素的抗性(英文)

目的:研究粉防己碱(Tet)和蝙蝠葛碱(Dau)能否减低抗三尖杉酯碱(Har)的人早幼粒白血病HL60抗性株对阿霉素(Dox)的抗性。方法:细胞计数法和克隆形成法测定药物毒性,流式细胞光度术分析细胞周期变化,荧光法测定Dox含量。结果:无细胞毒性的Tet和Dau明显地增强Dox对HL60抗性细胞的生长抑制作用,使克隆形成率从Dox单药的60％分别降低到0.2％,9.2％,使阻断在G_2M期的抗性细胞增多,但Tet和Dau不增强Dox对敏感的HL60细胞的毒性。Tet使胞内Dox积聚增加。结论:Tet和Dau减低抗Har的HL60细胞对Dox的抗性,其机制是增加Dox在细胞内积聚。     

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。     

(-)-S·R-蝙蝠葛苏林碱对谷氨酸引起的大鼠大脑皮质神经元损伤的保护作用

用细胞培养方法,在原代培养的大鼠皮质神经细胞上,观察了(-)-S·R-蝙蝠葛苏林碱对谷氨酸引起的神经元损伤的保护作用。以Fura-2/AM为Ca²⁺的荧光指示剂,用AR-CM-MIC阳离子测定系统观察(-)-S·R-蝙蝠葛苏林碱对谷氨酸诱发大鼠脑皮质神经细胞内Ca²⁺升高的影响。结果表明(-)-S·R-蝙蝠葛苏林碱能剂量依赖性地抑制谷氨酸的神经毒作用,对谷氨酸诱发的神经细胞内游离Ca²⁺升高有明显的抑制作用。提示蝙蝠葛苏林碱对缺血性脑损伤有保护作用。     

蝙蝠葛碱对异丙肾上腺素和Ca2+量效反—应及猫乳头肌电—机械活动的影响

蝙蝠葛碱对异丙肾上腺素量—效反应的影响与戊脉安和粉防己碱相似,不同于β-受体竞争性拮抗剂心得安。对Ca²⁺量—效反应的影响,亦与戊脉安和粉防己碱相似,表现为竞争性和非竞争性双重拮抗作用。在对猫乳头肌电—机械活动影响方面,对SEG的影响类似奎尼丁:R波降低,增宽,R-T延长;但同时显著抑制收缩力。结果说明蝙蝠葛碱可能具有“钙拮抗剂样”抗Ca²⁺作用和“奎尼丁样’抑制Na⁺内流的作用。     

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.     

粉防己碱,小檗胺等四氢异喹啉类生物碱对大鼠脑内M-胆碱受体的作用

用放射受体结合方法,研究了36种四氢异喹啉类生物碱及其半合成衍生物对大鼠脑内M-胆碱受体的结合特性。实验发现,粉防己碱对M-胆碱受体的亲和力最高,其K_i值为7.3×10^-8mol/L。小檗胺、四氢黄连碱和半合成原小檗碱衍生物B₁亦具有较高亲和力,K_i值分别为1.9×10^-7,6.8×10^-7和8.1×10^-7mol/L。四氢小檗碱半合成原小檗碱衍生物B₂,B₃,B₄,B₅,B₆和半合成小檗胺衍生物E₁及半合成蝙蝠葛碱衍生物D₁对M-胆碱受体的亲和力为中等强度,K_i值在1～2×10^-6mol/L之间。实验结果提示,某些四氢异喹啉类生物碱的药理作用可能与M-胆碱受体有关。     

α1-ADRENOCEPTORS ON RABBIT AORTIC SMOOTH MUSCLE CELLS IN CULTURE AND IN EXPERIMENTAL INTIMAL THICKENING

1. This study has defined α₁-adrenoceptors and their reactivity in rabbit aorta, following removal of the endothelium and formation of a myointimal thickening, and also in smooth muscle cells (SMC) in cell culture which had undergone serial passaging and changes in phenotype. 2. [³H]-prazosin binding to SMC from control aorta, vessels 2 weeks after endothelial denudation and sub-cultured SMC (passage 3–6) was specific (displaceable with 10 μmol/L phentolamine), and of high affinity to a single class of sites (K_d range: 71–114 pmol/L). The maximum binding density (B_max) of α₁-adrenoceptors on SMC from the neointima (11105 ± 771 sites/cell) was not significantly different to that of control medial SMC (14014 ± 2472 sites/cell). However, SMC cultured to passage 6, showed a 2-fold increase in B_max (30227 ± 4349 sites/cell). 3. The production of inositol phosphates (IP₁, IP₂ and IP₃) by SMC following 10μmol/L phenylephrine was assayed. Both freshly-dispersed aortic SMC and sub-cultured SMC were stimulated to produce increased inositol phosphates by the addition of phenylephrine which was completely inhibited by pre-incubation with 10 μmol/L phentolamine, suggesting that the stimulation was via α₁-adrenoceptors. 4. Maximal contractile responses of isolated thoracic and abdominal aortic rings to KCl (100 mmol/L), 5-HT and phenylephrine were unchanged two weeks after endothelial denudation. However, phenylephrine was significantly less potent (2.7-fold) in both areas of the aorta, while the potency of 5-HT was significantly enhanced (2.7-fold) after endothelial denudation only in the abdominal aorta. 5. The decreased sensitivity of the rabbit aorta to α₁-adrenoceptor agonists following endothelial denudation and the formation of a myointimal thickening is not due to changes in affinity or density of α₁-adrenoceptors. However multiple passaging of SMC in culture leads to an increase in α₁-adrenoceptor density. This change can be related to the altered cytodifferentiation of irreversible synthetic state SMC which are similar to those in atherosclerotic lesions.     

前胡丙素对Ang II致离体血管平滑肌细胞肥厚及胞内钙、NO含量和信号转导的影响

目的前胡丙素(Pra-C)对血管紧张素II(Ang II)致离体培养大鼠血管平滑肌细胞(SMCs)肥厚模型胞内游离钙浓度、NO含量和信号转导的影响。方法以Ang II刺激SMCs形成肥厚模型,用倒置显微镜测定SMCs面积;用Fura-2/AM测定单细胞内［Ca²⁺］i,Griess法测定NO含量;在PMA和ST(PKC激动剂及抑制剂)、PTX(Gi蛋白敏感毒素)作用下观察Pra-C对KCl和NE所致胞内［Ca²⁺］i浓度变化的影响。结果Pra-C组SMCs细胞面积较肥厚组减小39.01%,并接近正常细胞水平;NO含量明显增加;胞内［Ca²⁺］i对KCl和NE激动的反应明显低于肥厚组。PMA使肥厚SMCs［Ca²⁺］i升高,而ST及PTX则使之降低,Pra-C均使之恢复正常。结论Pra-C抑制Ang II致体外培养细胞SMCs肥厚,改善肥厚细胞因PKC和Gi蛋白的信号转导改变所致的［Ca²⁺］i改变。     

[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.