De novo synthesis and axoplasmic transport of [35S]methionine-substance P in explants of nodose ganglion/vagus nerve.
De novo synthesis and axoplasmic transport of [35S]methionine-substance P in explants of nodose ganglion/vagus nerve.
复制标题
结状神经节/迷走神经外植体中[35S]甲硫氨酸-P物质的从头合成和轴浆运输。
DOI：
10.1016/0006-8993(84)90155-0
复制
发表时间：
1984
期刊：
影响因子：
2.9
通讯作者：
Lewis,SF
中科院分区：
文献类型：
--
作者：
MacLean,DB;Lewis,SF
本文研究了豚鼠迷走神经中广泛分布的十一肽P物质的合成和转运。在初步的体内研究中，将颈迷走神经结扎在结状神经节远端2 cm处。24小时后，结扎近端3 mm神经节段P物质（IR-SP）含量为2147 ± 207 pg（mean±S.E.M.）。而未结扎神经的等节段为133 ± 31 pg/min，结状神经节为243 ± 55 pg/min。迷走神经在结状神经节上方夹伤，同时结扎远端2cm处，近端IR-SP含量减少50%，为1131 ± 99 pg（P < 0.01），而结状神经节含量增加到420 ± 140 pg（n. s.）。为了证实结节上挤压后的残留转运来自结状神经节合成的SP，在从灌注动物中取出的结状神经节和附着的远端迷走神经的外植体中研究SP合成和转运，并在体外维持长达24小时。在切除时，在神经节远端1.5 cm处结扎神经。结扎后24小时，近节IR-SP含量为1022 ± 142 pg，未结扎节为155 ± 22 pg，结状神经节为560 ± 72 pg。在单独的实验中，[35 S]蛋氨酸被添加到外植体培养基中，外植体保持不同的时间间隔。提取神经组织并进行连续反相高效液相色谱（HPLC），或用SP抗血清免疫沉淀，然后进行单一HPLC分离。到4小时，放射性标记的SP存在于结状神经节和较少量的近端段。到12小时，[35 S]SP同样存在于神经节和近端节段，而到18小时，三分之二或更多的新合成的肽存在于近端节段。在18小时，放射性标记的SP的数量与IR-SP含量在个别神经节段的协变。在外植体培养基中添加放线菌酮使[35 S]SP的合成减少了90%。这些研究表明：（1）豚鼠迷走神经内传出的免疫反应性SP约50%来自结状神经节，（2）结状神经节内SP的重新合成和输出发生在4 h内，（3）在体内和体外结扎研究中证实的IR-SP含量的变化准确地反映了结状神经节内正在进行的SP合成。该转运模型可为研究感觉迷走神经内SP或其他神经肽的合成调节提供一个有用的工具。
The synthesis and transport of substance P, the widely distributed undecapeptide, was studied in the vagus nerve of the guinea pig. In preliminary in vivo studies, the cervical vagus nerve was ligated 2 cm distal to the nodose ganglion. Twenty-four hours later, the content of immunoreactive substance P (IR-SP) in the 3-mm nerve segment proximal to ligature was2147 ± 207pg(mean±S.E.M.)vs133 ± 31pgin an equal segment of unligated nerver or243 ± 55pgin the nodose ganglion. When the vagus nerve was crushed above the ganglion and simultaneously ligated 2 cm distally, the IR-SP content proximal to the ligature was reduced 50% to1131 ± 99pg(P < 0.01), while nodose ganglion content increased to420 ± 140pg(n.s.).To confirm that residual transport following supranodose crush was derived from nodose ganglion-synthesized SP, SP synthesis and transport were studied in explants of nodose ganglion and attached distal vagus nerve removed from perfused animals and maintained in vitro for up to 24 h. At the time of resection, nerves were ligated 1.5 cm distal to the ganglion. Twenty-four hours following explantation, IR-SP content in proximal segments was1022 ± 142pg vs155 ± 22pgin unligated segments and560 ± 72pgin the nodose ganglion. Accumulation in the proximal segment was time dependent.In separate experiments, [35S]methionine was added to explant medium and the explants maintained for varying time intervals. nerve tissue was extracted and subjected to either serial reverse phase high performance liquid chromatography (HPLC), or immunoprecipitation with SP antiserum followed by a single HPLC separation. By 4 h, radiolabeled SP was present in nodose ganglia and lesser amounts in the proximal segments. By 12 h, [35S]SP was present equally in ganglia and proximal segments whereas by 18 h, two-thirds or more of the newly synthesized peptide was present in proximal segments. At 18 h, the quantity of radiolabeled SP covaried with IR-SP content in the individual nerve segments. The addition of cycloheximide to explant medium reduced [35S]SP synthesis by 90%.These studies demonstrate that: (1) approximately 50% of immunoreactive SP transported efferently within the vagus nerve of the guinea pig is derived from the nodose ganglion, (2) de novo SP synthesis within and export from the nodose ganglion occurs within 4 h, (3) the changes in IR-SP content demonstrated in in vivo and in vitro ligation studies accurately reflect ongoing SP synthesis within the nodose ganglion. This transport model may provide one useful tool for studying the regulation of synthesis of SP, or other neuropeptides, within the sensory vagus nerve.