脑池内注射的L-[甲基-³H]蛋氨酸和S-腺苷-L-[甲基-³H]蛋氨酸掺入大鼠脑磷脂的研究。

Incorporation of intracisternally administered L-[methyl-3H]methionine and S-adenosyl-L-[methyl-3H]-methionine into rat brain phospholipids.

作者信息

Zawad J S, Brown F C

出版信息

J Neurochem. 1985 Mar;44(3):808-11. doi: 10.1111/j.1471-4159.1985.tb12887.x.

DOI:10.1111/j.1471-4159.1985.tb12887.x

Abstract

The incorporation of intracisternally injected L-[methyl-3H]methionine [( 3H]Met) or S-adenosyl-L-[methyl-3H]methionine (Ado[3H]Met) into rat brain AdoMet and phospholipid pools was examined. When [3H]Met was administered, both AdoMet and phospholipid pools were labeled. However, exogenously injected Ado[3H]Met did not serve as a substrate for phospholipid-N-methyltransferases. It was concluded that only Ado[3H]Met formed in situ was utilized to methylate phospholipids and that this process was initiated on the cytoplasmic side of the membrane. The apparent biological half-life in brainstem of phosphatidyl-N-monomethylethanolamine and phosphatidyl-N,N-dimethylethanolamine formed from [3H]Met was 1.4 and 1.7 days, respectively. The half-life of phosphatidylcholine could not be determined due to interference from peripheral sources.

摘要

研究了脑池内注射L-[甲基-³H]蛋氨酸（[³H]Met）或S-腺苷-L-[甲基-³H]蛋氨酸（Ado[³H]Met）掺入大鼠脑内腺苷甲硫氨酸（AdoMet）和磷脂池的情况。当给予[³H]Met时，AdoMet和磷脂池均被标记。然而，外源性注射的Ado[³H]Met并非磷脂-N-甲基转移酶的底物。得出的结论是，仅原位形成的Ado[³H]Met被用于使磷脂甲基化，且该过程在膜的细胞质侧起始。由[³H]Met形成的磷脂酰-N-单甲基乙醇胺和磷脂酰-N,N-二甲基乙醇胺在脑干中的表观生物半衰期分别为1.4天和1.7天。由于外周来源的干扰，无法确定磷脂酰胆碱的半衰期。