大鼠脑室注射P物质引起的血压升高与脑啡肽和β-内啡肽有关

给乌拉坦麻醉大鼠侧脑室注射P物质(SP)10μg 引起的升压效应,可被脑室注射纳洺酮15μg 部分阻断。将抗β-内啡肽抗血清、抗甲啡肽抗血清及抗亮啡肽抗血清各10μl 分别注入侧脑室预处理60min 后,再注入 SP,其升压效应明显减弱;而抗强啡肽抗血清则对其无影响。上述结果提示:大鼠脑室注射 SP 引起的升压效应,可能是通过释放β-内啡肽和脑啡肽实现的。     

下丘脑室旁核加压素能神经元参与电针刺激对实验性内脏痛的抑制

本实验采用内脏痛的实验模型,探讨室旁核中的加压素在针刺抑制内脏痛中的作用。实验结果如下:(1)大鼠在在射酒石酸锑钾(0.1％,10ml/kg,i.p.)后,出现可定量的扭体反应,能作为观察内脏痛的客观指标。(2)电针对内脏痛有抑制效应,即具有镇痛作用。(3)电刺激室旁核,能加强电针对内脏痛的抑制效应,损毁室旁核,则此抑制效应基本消失。(4)脑室注射加压素抗血清(14μl)或加压素拮抗剂[d(CH_2)_5Tyr(Me)-AVP,500ng/5μl]都能明显减弱电针的抑制效应。(5)腹腔注射加压素拮抗剂(10μg/kg),不能翻转电针的抑制效应。上述实验结果表明,下丘脑室旁核的加压素能神经元参与了电针刺激对实验性内脏痛的抑制。     

Immunochemical and biological analysis of pheromone biosynthesis activating neuropeptide in Heliothis peltigera.

This study describes the preparation and characterization of a highly specific antiserum to Helicoverpa zea pheromone biosynthesis activating neuropeptide (Hez-PBAN), and the use of this antiserum, in an enzyme linked immunosorbent assay (ELISA), to determine: a) the content of endogenous PBAN in head extracts of male and female Heliothis peltigera; b) the level of PBAN at different developmental stages; and c) the content of PBAN in four different moth species. Cross-reactivity studies revealed that the antiserum is directed mainly toward the N-terminal region of the neuropeptide, and that it exhibits similar binding affinities toward the oxidized and reduced forms of PBAN. Analysis of PBAN content in head extracts of male and female H. peltigera, at scotophase, revealed the presence of 4.97 and 4.58 pmol, respectively, in 3-day-old moths, and 5.33 and 4.78 pmol, respectively, in 7-day-old moths. The similarity in the content of PBAN at both ages and sexes was in accordance with the amount of pheromonotropic activity in these extracts which stimulated pheromone biosynthesis to a similar level. Analysis of PBAN-like immunoreactivity (IR) in head extracts of H. peltigera larvae and pupae demonstrated the existence of the neuropeptide in the 4th larval instar and continued to increase as a function of development. No IR could be detected in the first three larval instars. The larval and pupal extracts also exerted pheromonotropic activity which followed a similar pattern. The activity in these extracts, however, was considerably lower than that found in adult male and female heads. IR was also detected in head extracts of three other Noctuidae moths: Helicoverpa armigera, Cornutiplusia circumflexa and Spodoptera littoralis, indicating a high degree of chemical and structural similarity of PBAN in these moths.     

一例硬皮病人自发抗核仁抗体的免疫荧光及其与银染的比较研究

从硬皮病人血清中筛选出一例含有自发抗核仁抗体的血清,利用这个血清对核仁抗原的性质及其在细胞中随分裂周期不同产生的分布变化做了初步研究,并把结果与核仁嗜银蛋白做了比较。间接免疫荧光染色及细胞化学分析表明,这种核仁抗原的性质是蛋白质,其分布与嗜银蛋白相似,在间期,抗原呈颗粒状簇集在核仁中,而在分裂中期,抗原颗粒与染色体NORs部位接合,但有证据指出,这种抗原蛋白与核仁嗜银蛋白有所不同,同时还发现,经长时间秋水仙素处理诱导产生微核化的多核细胞中尽管微核的数目远多于细胞中NORs的数目,免疫荧光染色和银染都显示出每个微核中类核仁小体的存在。这说明(1)类核仁小体也是由核仁物质构成;(2)某些类核仁小体的产生可能与NORs无关。对这个现象的意义进行了讨论。     

家兔中脑导水管周围灰质中注射八肽胆囊收缩素(CCK-8)拮抗吗啡镇痛和电针镇痛

家兔单侧PAG内注射CCK-83ng,能使静脉注射4mg/kg吗啡引起的镇痛作用降低73％或使电针镇痛效果降低67％。在1.5—6.0ng范围内呈量效关系。无硫的CCK-8无此作用。PAG内注射CCK受体拮抗剂proglumide 4μg可翻转CCK-8的抗吗啡镇痛作用。说明PAG部位注射外源性CCK-8可通过CCK受体对抗阿片镇痛。 PAG内注射CCK-8抗血清可显著增强静脉注射2mg/kg吗啡的镇痛效果。PAG内注射CCK抗血清本身也能引起痛阈轻度升高。说明PAG内有内源性的CCK-8发挥紧张性的抗阿片镇痛作用。     

高效价甘薯羽状斑驳病毒抗血清的制备

用嫁接方法将甘薯羽状斑驳病毒（ＳＰＦＭＶ）接种到Ｉ．ｓｅｔｏｓａ上扩繁,以０．２ｍｏｌ／ＬｐＨ７．２ＰＢＫ缓冲液、垫层差速离心、蔗糖密度梯度离心提取纯化ＳＰＦＭＶ。纯化的ＳＰＦＭＶＯＤ２６０／２８０的比值为１．２５。将纯化的ＳＰＦＭＶ免疫家兔制备抗血清,在环状沉淀和微量沉淀试验中,用提纯病毒测定抗血清的效价均为１：４０９６;以ＳＰＦＭＶ－ＩｇＧ为第一抗体,应用Ｄｏｔ－ＥＬＩＳＡ对甘薯和Ｉ．ｓｅｌｏｓａ叶片中的ＳＰＦＭＶ分别作了测定。     

Development of the magnetic capture system for recovery of Xiphinema americanum

Xiphinema americanum is listed as a quarantine nematode by The European Plant Protection Organisation because of its ability to transmit quarantine viruses. Detection of this nematode in soil samples, or in mixed nematode samples extracted from soil, is therefore of paramount importance. We recently described the use of magnetic beads (Dynabeads) in combination with probes such as lectins or antibodies for recovery of small endoparasitic nematodes including Meloidogyne spp. and Globodera rostochiensis from mixed nematode samples. Here we show that magnetic capture can be used with much larger nematodes such as X. americanum. We describe lectins and antisera that bind to the surface of this nematode and show that the antisera can be used in the Dynabeads system to recover and enrich X. americanum from mixed nematode samples.     

A Nucleoside Diphosphate Kinase from Paramecium tetraurelia with Protein Kinase Activity

Nucleoside diphosphate kinase (NDP kinase) from Paramecium was purified to homogeneity. The native enzyme was 80 kDa (by gel filtration), with subunits of 18 and 20 kDa. Near the amino terminus, 15 of 20 residues were identical with those in human NDP kinase, and 17 of 20 with the awd gene product from Drosophila. NDP kinase bound α-labeled ATP and GTP, and a photoreactive GTP analog labeled both subunits. Purified NDP kinase underwent autophosphorylation on a histidine and a serine residue using either ATP or GTP as a substrate. The enzyme also catalyzed acid-stable phosphorylation of casein and phosvitin. This protein kinase activity is distinct from the histidine phosphorylation that is part of the NDP kinase catalytic cycle. Antiserum against the purified protein from Paramecium cross-reacted with 16- to 20-kDa proteins in most species tested, and with a larger protein (44 kDa) in Paramecium, Xenopus, and two human lines. The multiple forms (20 and 44 kDa) of the NDP kinase in Paramecium and its protein kinase activity, suggest that the protein is more than a housekeeping enzyme; it may have regulatory roles such as those of the NDP kinase-like awd protein of Drosophila and Nm23 protein of humans.     

Immunoneutralization of insulin partially modifies dorsoventral patterning in developing frog embryos

Determination of anteroposterior and dorsoventral axes is an important early event in the development of vertebrates involving extensive cellular interactions including inductive events. Recently we showed that insulin plays an essential role in prepancreatic development of the frogMicrohyla ornata. In the present study we have investigated the effects of immunoneutralization of endogenous insulin on the process of pattern formation. Treatment of neurulating embryos with antiserum to insulin caused abnormal pattern formation. The defects included loss of normal architecture of the neural tube, reduction in the size of the neural tube and, most conspicuously, rotation of the dorsoventral axis of the neural tube, notochord and adjoining mesodermal elements. The effects could be alleviated partially by pretreatment of embryos with exogenous insulin. This supports our belief that insulin plays an important role in induction and pattern formation of the amphibian nervous system. In addition, using 2-deoxy-α-D-glucose, an inhibitor of glucose metabolism, it is shown that the stimulatory effects of exogenous insulin on developing frog embryos are, at least partially, through the glucose metabolism pathway. Preliminary results of this study were presented at the National Symposium on Genes and Human Environment, held at Hyderabad, February 1994 and DAE Symposium on Stress and Adaptive Responses in Biological Systems, held at Vadodara, March 1994.     

Vasoactive intestinal polypeptide (VIP) in the pig pancreas: role of VIPergic nerves in control of fluid and bicarbonate secretion

Vasoactive intestinal polypeptide (VIP) in the pig pancreas is localized to nerves, many of which travel along the pancreatic ducts. VIP stimulates pancreatic fluid and bicarbonate secretion like secretin. Electrical vagal stimulation in the pig causes an atropine-resistant profuse secretion of bicarbonate-rich pancreatic juice. In an isolated perfused preparation of the pig pancreas with intact vagal nerve supply, electrical vagal stimulation caused an atropine-resistant release of VIP, which accurately parallelled the exocrine secretion of juice and bicarbonate. Perfusion of the pancreas with a potent VIP-antiserum inhibited the effect of vagal stimulation on the exocrine secretion. It is concluded, that VIP is responsible for (at least part of) the neurally controlled fluid and bicarbonate secretion from the pig pancreas.