Lleu P L, Huxtable R J
Department of Pharmacology, College of Medicine, Arizona Health Sciences Center, Tucson 85724.
Neurochem Int. 1992 Jul;21(1):109-18. doi: 10.1016/0197-0186(92)90073-z.
Changes in taurine concentration and rate of methylation of phosphatidylethanolamine have been examined in rat brain synaptosomes over the course of development. At 7, 14, 21, 28 and 56 days of age, rats were injected i.p. with 300 microCi/kg [3H-methyl]methionine. Synaptosomes (P2B fraction) were isolated from the cerebral cortex 9 h later and incorporation of the methionine methyl group into phospholipid and protein was investigated. Synaptosomal taurine and methionine concentrations were determined at the same ages, as were the concentrations of the major classes of phospholipids (phosphatidylethanolamine, phosphatidylinositol, phosphatidylcholine and phosphatidylserine). Methionine concentration increased between day 7 and 14 and fell thereafter. Phospholipid methylation rates calculated from the specific activity of synaptosomal methionine were high from days 7 and 14 and then fell, whereas protein methionylation increased between day 7 and 28 and then decreased. A strong correlation was found between the taurine concentration of the synaptosome and phospholipid methylation rates during brain development. Protein methionylation rates, however, showed no correlation with taurine concentration.
在大鼠大脑发育过程中，研究了其脑突触体中牛磺酸浓度和磷脂酰乙醇胺甲基化速率的变化。在7、14、21、28和56日龄时，给大鼠腹腔注射300微居里/千克的[³H-甲基]甲硫氨酸。9小时后从大脑皮层分离出突触体（P2B组分），并研究甲硫氨酸甲基基团掺入磷脂和蛋白质的情况。在相同年龄测定突触体中牛磺酸和甲硫氨酸的浓度，以及主要磷脂类（磷脂酰乙醇胺、磷脂酰肌醇、磷脂酰胆碱和磷脂酰丝氨酸）的浓度。甲硫氨酸浓度在第7天至第14天之间升高，此后下降。根据突触体甲硫氨酸的比活性计算的磷脂甲基化速率在第7天至第14天较高，然后下降，而蛋白质甲硫基化在第7天至第28天之间增加，然后减少。在大脑发育过程中，发现突触体的牛磺酸浓度与磷脂甲基化速率之间存在很强的相关性。然而，蛋白质甲硫基化速率与牛磺酸浓度无关。
