Effects of 8-OH-DPAT,buspirone and ICS 205-930 on feeding in a novel environment: comparisons with chlordiazepoxide and FG 7142

Previously, the 5-hydroxytryptamine (5-HT)_1A receptor agonists 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) and buspirone and the 5-HT₃ receptor antagonist ICS 205-930 have been shown to exert anxiolytic-like effects in several animal models. In the experiments reported here the effects of these compounds on feeding behaviour and food preference in a novel environment were examined, and compared with the effects of the anxiolytic drug chlordiazepoxide and the anxiogenic compound FG 7142. Chlordiazepoxide significantly reduced the latency to begin eating and prolonged the total time spent eating; chlordiazepoxide also abolished food neophobia, by significantly increasing the time spent eating novel food items. In contrast, FG 7142 significantly increased eating latency and reduced eating duration. Both 8-OH-DPAT and buspirone significantly enhanced eating duration, but unlike chlordiazepoxide eating was directed only towards the familiar food. In addition buspirone, but not 8-OH-DPAT, reduced eating latency. ICS 205-930 significantly increased eating latency and reduced eating duration; however, these effects were observed only at the lowest dose tested. All of these behavioural effects were observed only when animals were unfamiliar with the testing situation, and cannot be accounted for in terms of changes in mechanisms controlling hunger. The behavioural paradigm used in these experiments may induce a competition between the drives to explore a novel environment and to eat. It is suggested that the tendency of buspirone and 8-OH-DPAT to suppress exploratory activity may thus result in enhanced feeding duration. Similarly enhanced exploratory activity induced by ICS 205-930 may result in animals taking longer to contact food, and spending less time eating. These results serve to illustrate that compounds which have different pharmacological actions, but which have been shown in other tests to have anxiolytic-like activity, can induce different behavioural effects. The suitability of this behavioural test for assessing anxiolytic effects of drugs is discussed.     

Differential assay of human pancreatic and salivary α-amylases in serum using a new fluorogenic substrate

The difference in the mode action of human pancreatic and salivary α-amylases on $\text{O-6-}\text{deoxy}\text{-6-[(2-}\text{pyridyl)amino}\text{]-α-}\text{d}\text{-glucopyranosyl}\text{-(1 → 4)-O-α-}\text{d}\text{-glucopyranosyl}\text{-(1 → 4)-O-α-}\text{d}\text{-glucopyranosyl}\text{-(1 → 4)-O-α-}\text{d}\text{-glucopyranosyl}\text{-(1 → 4)-O-α-}\text{d}\text{-glucopyranosyl}\text{-(1 → 4)-}\text{d}\text{-glucitol}$ (FG6R), a fluorogenic derivative of maltohexaitol, was found. The products of the enzymatic hydrolysis were analyzed by high-performance liquid chromatography (HPLC) in 8 min. FG6R was hydrolyzed by these enzymes to $\text{O-6-}\text{deoxy}\text{-6-[(2-}\text{pyridyl)amino}\text{]-α-}\text{d}\text{-glucopyranosyl}\text{-(1 → 4)-O-α-}\text{d}\text{-glucopyranosyl}\text{-(1 → 4)-}\text{d}\text{-glucose}$ (FG3) and maltotriitol, or $\text{O-6-}\text{deoxy}\text{-6-[(2-}\text{pyridyl)amino}\text{]-α-}\text{d}\text{-glucopyranosyl}\text{-(1 → 4)-O-α-}\text{d}\text{-glucopyranosyl}\text{-(1 → 4)-O-α-}\text{d}\text{-glucopyranosyl}\text{-(1 → 4)-}\text{d}\text{-glucose}$ (FG4) and maltitol.Pancreatic α-amylase produced more FG4 than salivary α-amylase. Taking advantage of the differences in action of the two amylases, a differential α-amylase assay in serum was performed. The method is simple and rapid and can be used for routine clinical assays of α-amylases.     

β-Carbolines can enhance or antagonize the effects of punishment in mice

Six -carboline ligands at central benzodiazepine (BZ) receptors were tested for their anxiolytic or anxiogenic properties in mice in the four-plate test. ZK 93 423 and ZK 91 296 increased activity which had been suppressed by punishment (1 mA, 60 ms footshock) at doses which exerted no effect on unpunished locomotion. ZK 93 426, ZK 90 886, FG 7142, and DMCM exerted no antipunishment activity themselves, and antagonized the ability of diazepam to increase both punished and unpunished locomotor activity. DMCM, FG 7142, and ZK 90 886, but not ZK 93 426, also enhanced the ability of a reduced level of footshock (0.3 mA) to suppress activity. This propunishment activity of DMCM and ZK 90 886 took place at doses which had no effect on unpunished locomotion. The nature of the effect of the individual -carbolines on punishment was related to the nature of their interaction with the BZ/GABA receptor/chloride channel complex (GBC complex). Thus the antipunishment properties of ZK 93 423 and ZK 91 296 were associated with their ability to increase binding of ³⁵S-t-butylbicyclophosphorothionate (TBPS) to its binding site associated with the chloride channel, whereas DMCM, FG 7142 and ZK 90 886, which exerted propunishment effects, reduced TBPS binding. ZK 93 426, which was neutral with respect to punished activity, had the weakest effect on TBPS binding. These results are discussed in the context of a possible role of the GBC complex in anxiety.     

A β-carboline antagonizes benzodiazepine actions but does not precipitate the abstinence syndrome in cats

The -carbolines, which are potent ligands for benzodiazepine receptors, antagonize the pharmacological actions of benzodiazepines. In the cat, the stable -carboline derivative methylamide--carboline-3-carboxylate, FG 7142, and the specific benzodiazepine antagonist Ro 15-1788 reversed behavioral and electroencephalographic (EEG) changes produced by a single dose of diazepam. Surprisingly, the -carboline did not elicit signs of withdrawal when given after 22 days of a daily dose regimen of diazepam, while Ro 15-1788 precipitated an acute abstinence syndrome largely characterized by tremors, increased muscle tone, back arching, myoclonic jerks and pupil dilatation. Unlike Ro 15-1788, the -carboline produced effects of its own such as behavioral states of arousal and fearfulness. These findings indicate that the -carboline functionally interacts with benzodiazepine receptors in a manner unlike that seen with typical agonists and antagonists.     

犬颞骨切除术后血液流变学的变化

目的 为探讨手术后缺血性心、脑血管病的发病机理。方法 应用8条犬于颞骨切除术后不用任何治疗，连续观察5d内血液流变学的变化。结果 犬术后2h全血粘度明显升高（P＜0.05），24h后恢复并稳定在正常状态；血浆粘度一直无明显改变；血沉于术后24h明显加快（P＜0.05），持续至5d；纤维蛋白原亦于2h后开始增加，至第5d时具有统计学意义（P＜0.05）；而红细胞压积于术后2h明显升高（P＜0.05),24h显著下降（P＜0.05），也持续至5d，并与全血粘度的改变呈正相关（r＝0.778，P＜0.05）。结论 在正常生理情况下，手术可引起血液流变学的显著异常，但由于机体的自我调节作用，24h以内红细胞压积下降，血粘度恢复正常，并稳定至5d以后，而对血沉加快和纤维蛋白原升高的调节作用不明显。因此，为了预防手术后早期发生缺血性心、脑血管疾病，应在手术后24h以内采用血稀释疗法，而24h以后则应针对血沉加快及纤维蛋白原增加予以治疗。     

60Co-γ射线照射对听觉传导通路的影响

目的 建立放射性脑损伤的动物模型,采用荧光金(FG)逆行追踪法探讨放射对听觉传导通路的影响,为放射性听力损伤的防治提供实验依据.方法 正常成年小鼠20只,体重25～30g,雌雄不限.分为正常对照组和照射组(行60Co-γ射线、单次30 Gy全脑照射后8周),每组10只小鼠.取脑前5d,通过立体定位,插入吸有荧光金的微玻管,用微电流将荧光金导入内侧膝状体(MG)以追踪听觉传导通路的神经元的分布与损伤后改变.结果 正常对照组在被盖背侧核中央周围部、被盖背外侧核及被盖背外侧核腹侧部、下丘中央核、外上橄榄、内侧上橄榄、斜方体核、蜗神经腹侧核、橄榄耳蜗束和蜗神经核浅胶质带可见FG标记细胞,照射组在上述相应部位亦可见FG标记细胞,但细胞形态和细胞分布密度均与正常对照组有明显不同.结论 放射对听觉传导通路的各级神经元存在不同程度的损伤.     

Long-lasting proconflict effect induced by chronic administration of the beta-carboline derivative FG 7142

In this study, the effect of the chronic administration of the benzodiazepine (BZD) receptor ligand FG 7142 on the rat conflict test was examined. Rats chronically treated with FG 7142 (15 mg/kg, i.p. twice a day for 10 days) had an enhanced sensitivity to punishment at 4 and 15 days after the last treatment. This 'proconflict' effect was prevented by the concurrent administration of the BZD antagonist Ro 15-1788. The hypothesis that the long-lasting proconflict effect of chronic FG 7142 administration is the consequence of a persistent down-regulation of the GABAergic transmission is discussed.     

阴茎包皮及包皮系带内SP免疫阳性神经末梢的分布和来源

目的观察成人阴茎包皮和包皮系带内P物质(substanceP,SP)免疫阳性神经末梢的分布和来源。方法免疫组织化学法观察SP免疫阳性神经末梢的分布,荧光金(fluoro-gold,FG)逆行追踪和SP免疫荧光标记相结合法研究大鼠包皮系带内SP免疫阳性神经末梢的来源。结果成人阴茎包皮及包皮系带内均有密集的SP免疫阳性神经末梢存在,这些神经末梢主要位于表皮基底层,呈树枝状或念珠状分布,大多成束走行。阴茎系带处SP免疫阳性神经末梢的分布密度明显大于阴茎包皮处。FG逆标阳性细胞位于大鼠第六腰髓对应的背根神经节(L6-DRG)和第一骶髓对应的背根神经节(S1-DRG)。阳性细胞大中小不等,大多沿神经束成行排列或散在分布。SP免疫荧光标记细胞大多为中小型,呈深红色。FG/SP双标阳性细胞均为中小型,其数量占FG逆标阳性细胞总数的三分之一。结论SP参与了阴茎包皮及包皮系带感觉信息的传递。大鼠阴茎包皮系带内SP免疫阳性神经末梢源自于L6-DRG和S1-DRG。     

Hydrodynamic characterization of recombinant human fibrinogen species

Introduction

Fibrinogen is a key component of the blood coagulation system and plays important, diverse roles in several relevant pathologies such as thrombosis, hemorrhage, and cancer. It is a large glycoprotein whose three-dimensional molecular structure is not fully known. Furthermore, circulating fibrinogen is highly heterogeneous, mainly due to proteolytic degradation and alternative mRNA processing. Recombinant production of human fibrinogen allows investigating the impact on the three-dimensional structure of specific changes in the primary structure.

Methods

We performed analytical ultracentrifugation analyses of a full-length recombinant human fibrinogen, its counterpart purified from human plasma, and a recombinant human fibrinogen with both Aα chains truncated at amino acid 251, thus missing their last 359 amino acid residues.

Results

We have accurately determined the translational diffusion and sedimentation coefficients (D_t(20,w)⁰, s_(20,w)⁰) of all three species. This was confirmed by derived molecular weights within 1% for the full length species, and 5% for the truncated species, as assessed by comparison with SDS-PAGE/Western blot analyses and primary structure data. No significant differences in the values of D_t(20,w)⁰ and s_(20,w)⁰ were found between the recombinant and purified full length human fibrinogens, while slightly lower and higher values, respectively, resulted for the recombinant truncated human fibrinogen compared to a previously characterized purified human fibrinogen fragment X obtained by plasmin digestion.

Conclusions

Full-length recombinant fibrinogen is less polydisperse but hydrodynamically indistinguishable from its counterpart purified from human plasma. Recombinant Aα251-truncated human fibrinogen instead behaves differently from fragment X, suggesting a role for the Bβ residues 1–52 in inter-molecular interactions. Overall, these new hydrodynamic data will constitute a reliable benchmark against which models of fibrinogen species could be compared.     

骨髓基质干细胞与纤维蛋白胶复合修复陈旧性关节软骨缺损的实验研究

目的建立组织工程方法修复陈旧性关节软骨缺损的动物模型,研究骨髓基质干细胞(BMSCs)与纤维蛋白胶(FG)的混合物修复陈旧性关节软骨缺损的效果。方法在新西兰大白兔股骨髁关节面制造圆形缺损,每孔直径4mm,深度约3mm,达松质骨。术后12周利用自体BMSCs与FG混合物进行修复。将36只兔共72侧膝关节随机分为空白对照组、陈旧修复组、新鲜修复组3组。术后分别在4、8、12、24、32和48周取材进行大体、组织学观察,参照Pineda标准对新生组织评分对比缺损修复的情况及新生组织的类型。结果陈旧组与新鲜组两种混合物修复组在甲苯胺蓝变色反应表明其与周围正常软骨无明显区别,均为类透明软骨组织修复。而对照组12周时为纤维软骨修复,后期为纤维组织和板层骨修复。陈旧组与新鲜组各期平均组织学和组织化学得分差异无显著性意义(P>0.05),但均高于对照组(P<0.05)。Pineda评分后数据做方差分析,8、12和24周陈旧组与新鲜组比较差异无显著性意义(P>0.05),这两组在第4周比较差异有显著性意义(P<0.05)。陈旧组与新鲜组2～48周期间关节功能良好。结论陈旧性关节软骨缺损和新鲜缺损应用BMSCs与FG复合修复的效果无明显差异。明确了BMSCs与FG的混合物在短期内能够良好地修复陈旧性关节软骨全层缺损,长期效果还有待研究。