Barret L, Torch S, Leray C L, Sarliève L, Saxod R
Laboratorie de Neurobiologie du Dèveloppement, Université Joseph Fourier, Saint Martin d'Hères, France.
Neurotoxicology. 1992 Fall;13(3):601-14.
Trigeminal nerve impairment is one of the main features of the clinical spectrum observed after trichloroethylene (Tce) exposure. A morphometric study of teased fibres, an analysis of the fatty acid composition of total lipids of the trigeminal trunk, measurements of myelin basic protein (MBP) and of 2'-3'-cyclic nucleotide 3' phosphohydrolase (CNP) activity were used to characterize this lesion. Furthermore, the effects of Tce and of dichloroacetylene (Dca), a breakdown product supposed to be the main cause of the trigeminal neuropathy, were compared under the same experimental conditions. Results showed a significant decrease of the internode length and of the mean fibre diameter in the Dca group whereas these values, although also diminished, were not significantly affected in the Tce group. In the trigeminal nerve, this was associated with a significant (46%) decrease in sigma. (n-6) fatty acid and a 22% decrease in sigma. (n-3) fatty acid contents in the Tce group whereas these decreases were respectively 32% in sigma. (n-6) fatty acid and 27% (significant) in sigma. (n-3) fatty acid contents in the Dca group. In this group, a 64% increase in sigma. Fatty aldehydes was also observed. Finally, Tce or Dca had only a slight effect on the overall profile of fatty acid content in the brain and no significant variation was observed in MBP level and CNP activity. Both compounds can thus induce trigeminal nerve alterations, but with a higher intensity for Dca.
三叉神经损伤是三氯乙烯（Tce）暴露后临床症状谱的主要特征之一。通过对 teased 纤维进行形态计量学研究、分析三叉神经干总脂质的脂肪酸组成、测量髓鞘碱性蛋白（MBP）和 2'-3'-环核苷酸 3' 磷酸水解酶（CNP）活性来表征这种损伤。此外，在相同实验条件下比较了 Tce 和二氯乙炔（Dca，一种被认为是三叉神经病变主要原因的分解产物）的作用。结果显示，Dca 组的节间长度和平均纤维直径显著降低，而 Tce 组的这些值虽然也有所降低，但未受到显著影响。在三叉神经中，这与 Tce 组中 σ.(n - 6) 脂肪酸显著降低（46%）和 σ.(n - 3) 脂肪酸含量降低 22% 相关，而在 Dca 组中，这些降低分别为 σ.(n - 6) 脂肪酸 32% 和 σ.(n - 3) 脂肪酸含量 27%（显著）。在该组中，还观察到 σ. 脂肪醛增加了 64%。最后，Tce 或 Dca 对大脑中脂肪酸含量的总体分布只有轻微影响，并且在 MBP 水平和 CNP 活性方面未观察到显著变化。因此，这两种化合物均可引起三叉神经改变，但 Dca 的作用强度更高。
