Sato C, Yu R K
Department of Biochemistry and Molecular Biophysics, Medical College of Virginia, Virginia Commonwealth University, Richmond.
Dev Neurosci. 1990;12(3):153-8. doi: 10.1159/000111845.
The (C57BL/6J X DBA/2J) F1 or B6D2F1 hybrid mice are known to exhibit a transitory hypermyelinating activity compared with their parental strains B6 and D2. These mice exhibit an elevated accumulation of cerebrosides in the brain which can be explained by an increase in their synthesis. Analysis of the two major cerebroside species indicated that the elevated content of total cerebrosides in the cerebellum and cerebrum of B6D2F1, as well as D2B6F1 hybrids, reflected an increased accumulation of the hydroxylated species. The UDP-galactose:ceramide galactosyltransferase (CgalT) activities in B6, D2 and hybrid mice were studied using as substrates alpha-hydroxy fatty acid (HFA)-containing ceramides or normal fatty acid (NFA)-containing ceramides (HFA- and NFA-CgalT activities, respectively). Both CgalT activities were found to be about 2 times higher in the cerebellum than in the cerebrum for all the strains studied. Before 20 days of age, the HFA-CgalT activities in B6D2F1, D2B6F1 and D2 mice were higher than in B6. However, at 20 days, there was no difference between B6 and D2 while the HFA-CgalT activity in the hybrids remained about 20% higher than in the parental strains. In contrast, no strain differences could be detected for the NFA-CgalT activity at all ages. The data suggest that the increased synthesis of brain cerebrosides in the B6D2F1 and D2B6F1 strains of mice could be largely accounted for by an increased HFA-CgalT activity.
已知（C57BL/6J×DBA/2J）F1或B6D2F1杂交小鼠与其亲本品系B6和D2相比，表现出短暂的过度髓鞘形成活性。这些小鼠大脑中脑苷脂的积累增加，这可以通过其合成增加来解释。对两种主要脑苷脂种类的分析表明，B6D2F1以及D2B6F1杂交小鼠小脑和大脑中总脑苷脂含量的升高反映了羟基化种类积累的增加。使用含α-羟基脂肪酸（HFA）的神经酰胺或含正常脂肪酸（NFA）的神经酰胺作为底物（分别为HFA-CgalT活性和NFA-CgalT活性），研究了B6、D2和杂交小鼠中UDP-半乳糖：神经酰胺半乳糖基转移酶（CgalT）的活性。在所研究的所有品系中，发现两种CgalT活性在小脑中均比在大脑中高约2倍。在20日龄之前，B6D2F1、D2B6F1和D2小鼠中的HFA-CgalT活性高于B6小鼠。然而，在20日龄时，B6和D2之间没有差异，而杂交小鼠中的HFA-CgalT活性仍比亲本品系高约20%。相比之下，在所有年龄段均未检测到NFA-CgalT活性的品系差异。数据表明，B6D2F1和D2B6F1品系小鼠大脑中脑苷脂合成增加可能很大程度上是由HFA-CgalT活性增加所致。
