嘌呤受体P2Y在免疫应答中的功能研究进展

P2Y受体是嘌呤受体当中的一个小家族,属于GPCRs(G-protein coupled receptors)代谢型受体,通过选择性结合胞外核苷酸分子如ATP、ADP、UTP、UDP和UDP-glucose而激活。P2Y受体在全身各组织细胞中广泛表达,调控了细胞的多种生理功能。随着研究的深入,发现P2Y受体及其胞外核苷酸分子在免疫应答过程中亦发挥着重要的调控作用。     

Mizolastine（MIZ）对趾叶炎小鼠趾部组织VEGF表达的影响

用组织化学和免疫组化的染色方法对趾叶炎发生过程中正常组、造模组和低、中、高剂量治疗组小鼠趾部组织血管内皮生长因子（VEGF）表达水平、血管数量和肥大细胞及其脱颗粒的动态变化进行了研究.结果表明,造模组小鼠在免疫后14d,VEGF表达均达到一个峰值,而后表达开始减弱,21d后表达开始增强,均极显著高于同一时相的正常组（P〈0.01）.低、中、高剂量治疗组的VEGF表达均极显著低于同一时相造模组,其中,低剂量治疗组同一时相均极显著高于正常组（P〈0.01）,中剂量治疗组除免疫后前3个时相显著外（P〈0.05）,免疫后35d与正常组不显著（P〉0.05）,高剂量治疗组除免疫后14d显著外（P〈0.05）,其余各时相均与正常组不显著（P〉0.05）,治疗各组小鼠的VEGF表达水平随药物浓度的增大和免疫时间的延长而逐渐减弱;真皮内出现了许多增生的小动脉,管壁增厚,管腔内有血栓形成,且血管形成与肥大细胞及其脱颗粒的变化均与VEGF的表达趋势相吻合.Mizo-lastine（MIZ）可以显著抑制肥大细胞脱颗粒、VEGF的表达和血管形成.     

低氧运动对大鼠血清VEGF含量及心肌VEGF基因和蛋白表达的影响

目的:观察低氧和不同运动强度对大鼠血清血管内皮生长因子(VEGF)含量及心肌VEGF基因和蛋白表达的影响。方法:SD大鼠随机分成6组:常氧对照组(NC),低氧对照组(HC),常氧低强度运动组(NEL),低氧低强度运动组(HEL),常氧高强度运动组(NEH),低氧高强度运动组(HEH)。NC、NEL和NEH组在常氧环境下生活,HC、HEL和HEH组在氧含量14.1%的低氧环境下生活。NEL和HEL、NEH和HEH组运动强度分别为15.2 m/min和26.8 m/min,跑台坡度均为10°,40min/天,6天/周。各组大鼠经实验在运动组最后一次运动后24h取血和心脏,检测VEGF含量,运用RT-PCR和WesternBlotting技术检测心肌VEGFmRNA和蛋白表达量。结果:血清VEGF含量随缺氧程度的加深有逐渐下降的趋势,且HEH组下降最为显著(P﹤0.01);RT-PCR和Western Blotting心肌VEGFmRNA和蛋白结果随缺氧程度的加深表达量呈逐渐升高趋势。结论:(1)低氧、运动以及低氧运动都能使血清VEGF含量减少,而此时心肌VEGF基因和蛋白表达均增强。推测是肌组织对循环中VEGF的摄取、利用增加,减少了血清VEGF含量;(2)VEGF的基因和蛋白表达程度与缺氧刺激程度关系密切;(3)缺氧相关因子含量和表达量的变化可作为机体对缺氧适应能力评价的指标。     

Presence of benzodiazepine binding sites (receptors) and amplification thereof by imprinting inTetrahymena

Summary LiveTetrahymena cells bound³H-diazepam specifically, as demonstrated by autoradiographic evidence of displacement of about 25% of labeled diazepam in the presence of a 1000-fold amount of cold diazepam. The³H-diazepam bound to membrane preparations isolated from untreated (control) cells was not displaced by cold diazepam, whereas cells involved in primary interaction (imprinting) with diazepam showed amplification and specificity of diazepam binding in both in vivo (cell suspension) and in vitro (pellicle) systems, as well as displacement of bound label in the presence of 1000-fold cold diazepam. It appears that diazepam induced imprinting and, consequently, also the formation of specific receptors inTetrahymena.     

Lack of effects of 5-HT3 antagonists on normal and morphine-attenuated sexual behaviours in female and male rats

Although 5-HT₁ and 5-HT₂ receptor activity is known to influence copulation, the effects of 5-HT₃ receptor-selective drugs on sexual activity have yet to be systematically studied. The following experiments investigated the effects of the 5-HT₃-selective antagonists MDL 72222, ondansetron and ICS 205-930 on female sexual behaviour; male rats were studied using ondansetron and granisetron. These compounds influenced neither male nor female copulatory behaviours, suggesting that 5-HT₃ receptors contribute little to the modulation of sexual activity. 5-HT₃ receptor antagonists block certain opioid-induced behaviours and opioids selectively inhibit sexual behaviours; therefore, the ability of ondansetron and ICS 205-930 to modify morphine-attenuated copulatory activity was also tested. While morphine inhibited copulation, 5-HT₃ antagonists failed to reverse the effects.     

Interferon receptors and their role in interferon action

Summary Interferon (IFN)_proteins interact with cells through specific cell surface receptors, some of which have been purified and cloned. The alpha-IFNs and beta-IFN bind to a common receptor (type I), whereas gamma-IFN binds to a separate receptor (type II). Both types of high-affinity receptors have been demonstrated on a variety of different kinds of cells but in relatively low numbers (10²–10⁴/cell). The relationship between IFN binding to receptors and the ways in which IFNs may affect cellular physiology and gene expression is discussed.     

大鼠心脏胞浆胞核雌激素受体的羟磷灰石放射分析法

用羟磷灰石放射分析法分析大鼠心脏胞浆、胞核雌激素受体,表明大鼠心脏雌激素受体具有可饱和性、低容量和高亲和力、甾体特异性和稳定结合等特性;饱和分析表明雌、雄鼠心脏胞浆雌激素受体最大结合容量分别为6.91±1.08fmol/mg蛋白质和6.05±0.93fmol/mg蛋白质((?)±SD),雌鼠心脏胞核雌激素受体最大结合容量为138.3±23.8 fmol/mg DNA((?)±SD);单点分析测得雌、雄鼠心脏胞浆雌激素受体的饱和容量分别为4.25±0.72fmol/mg蛋白质(n=10)和3.98±0.87fmol/mg蛋白质(n=10)((?)±SD),雌鼠心脏胞核雌激素受体的饱和容量为113.45±2.87fmol/mg DNA(n=10)((?)±SD)。相同5份雌鼠心脏胞浆、胞核雌激素受体的最大结合容量的变异系数分别为3.69％和7.46％,表明此方法重复性好。     

Melatonin biosynthesis in the mammalian pineal gland

Summary Rhythmic production of melatonin by the mammalian pineal occurs in response to noradrenergic stimulation which produces a cascade of biochemical events within the pinealocyte. In the rat, massive changes in NAT activity result from an increase in intracellular c-AMP levels produced by a synergistic interaction whereby an ₁ activation amplifies -adrenergic stimulation. The intracellular events mediating this effect are described. A major aspect of the temporal control of melatonin production is the programmed down-regulation of responses to noradrenergic stimulation once the initial surge of c-AMP is produced. Noradrenergic activation of the gland also influences other enzymic functions, including tryptophan hydroxylase and HIOMT activities, and produces a dramatic increase in intracellular c-GMP levels. Other neurotransmitters and neuropeptides, e.g. VIP, may also influence pineal function and comparisons are, made between the rat, the subject of the bulk of experimental studies, and other species.