Alteration of ethanolamine glycerophospholipid turnover in trembler dysmyelinating mutant: An analysis of the sciatic nerve by biochemistry and radioautography.
Alteration of ethanolamine glycerophospholipid turnover in trembler dysmyelinating mutant: An analysis of the sciatic nerve by biochemistry and radioautography.
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DOI：
10.1016/0197-0186(90)90045-u
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发表时间：
1990-01-01
影响因子：
4.2
通讯作者：
Piciotti, M
中科院分区：
文献类型：
--
作者：
Do Thi, N A;Bourre, J M;Piciotti, M
腹膜内和局部注射标记乙醇胺后，比较了 Trembler 脱髓鞘突变型小鼠和对照小鼠周围神经中磷脂的周转情况。在突变体坐骨神经中，神经化学分析表明，[(14)C]乙醇胺掺入坐骨神经 EGP（乙醇胺甘油磷脂）中的速度在 Trembler 突变体中比对照小鼠高得多。此外，(14)C 标记的 EGP 在 Trembler 中的衰减速度比在正常动物中更快。 Trembler 坐骨神经中 EGP 的加速周转会影响二酰基-EGP，而烯基酰基-EGP（缩醛磷脂）的更新速度比对照组慢。超微结构水平的定量放射自显影研究证实，颤抖神经纤维中标记的初始增加在轴突、雪旺细胞和髓鞘中是不同的。电镜放射自显影确实表明，在 Trembler 轴突中观察到的高标记含量优先发生在轴突的有髓鞘部分，并在 1 周内下降。在轴突的有髓鞘和无髓鞘部分中，大部分放射性包含在轴膜和光滑轴浆网中。第 1 天，在 Trembler 神经纤维的髓鞘中发现的标记增加了 10 倍，这引发了标记 EGP 来源的问题，要么是通过雪旺细胞中的刺激合成，要么是通过轴突运输的磷脂转移。相比之下，对照神经的轴突、雪旺细胞和髓鞘的标记在同一时期保持稳定。
The turnover of phospholipids was compared in peripheral nerves of Trembler dysmelinating mutant and control mice, after intraperitoneal and local injection of labeled ethanolamine. In the mutant sciatic nerve, neurochemical analysis showed that [(14)C]ethanolamine is incorporated into EGP (ethanolamine glycerophospholipids) of the sciatic nerve at a much higher rate in Trembler mutant than in control mice. Furthermore the decay rate of (14)C-labeled EGP is faster in Trembler than in normal animals. The accelerated turnover of EGP in Trembler sciatic nerve affects the diacyl-EGP while the renewal of the alkenylacyl-EGP (plasmalogens) is slower than in controls. Quantitative radioautographic study at the ultrastructural level corroborate that the initial increase of the label in Trembler nerve fibers was different in axons, Schwann cells and myelin sheaths. EM radioautographs reveal indeed that the high label content observed in Trembler axons takes place preferentially in the myelinated portions of axons and drops within 1 week. In both myelinated and unmyelinated segments of the axons, the majority of the radioactivity was contained in axolemma and smooth axoplasmic reticulum. The 10-fold increase of label found in the myelin sheath of Trembler nerve fibers at 1 day raises the question of the origin of the labeled EGP, either by a stimulated synthesis in Schwann cells or by transfer from axonally transported phospholipids. In contrast, the label of axons, Schwann cells and myelin sheaths of control nerve remains stable during the same period.