Callery P S, Geelhaar L A
J Neurochem. 1985 Sep;45(3):946-8. doi: 10.1111/j.1471-4159.1985.tb04085.x.
Intraperitoneal injection of the cyclic imine 1-piperideine in mice resulted in measurable quantities of 5-aminopentanoic acid in brain. 5-Aminopentanoic acid is a methylene homologue of gamma-aminobutyric acid (GABA) that is a weak GABA agonist. 5-Aminopentanoic acid formed in the periphery was ruled out as the source of brain 5-aminopentanoic acid based on the absence of detection in brain following injection of 100 mg/kg of 5-aminopentanoic acid. Deuterium-labeled 1-piperideine was prepared by exchange in deuterated phosphate buffer. Injection of [3.3-2H2]1-piperideine yielded [2.2-2H2]5-aminopentanoic acid in brain. The results are consistent with uptake of 1-piperideine into brain and oxidation of the precursor to 5-aminopentanoic acid. Inhibition of GABA catabolism by pretreatment with aminooxyacetic acid increased brain concentrations of 5-aminopentanoic acid formed from 1-piperideine, suggesting that 5-aminopentanoic acid is an in vivo substrate of 4-aminobutyrate:2-oxoglutarate aminotransferase.
给小鼠腹腔注射环亚胺1-哌啶会导致大脑中出现可测量量的5-氨基戊酸。5-氨基戊酸是γ-氨基丁酸（GABA）的亚甲基同系物，是一种弱GABA激动剂。基于注射100mg/kg的5-氨基戊酸后在大脑中未检测到，排除了在外周形成的5-氨基戊酸作为大脑中5-氨基戊酸来源的可能性。通过在氘代磷酸盐缓冲液中交换制备了氘标记的1-哌啶。注射[3,3-2H2]1-哌啶后，大脑中产生了[2,2-2H2]5-氨基戊酸。结果与1-哌啶被摄取到大脑中并将前体氧化为5-氨基戊酸一致。用氨氧基乙酸预处理抑制GABA分解代谢会增加由1-哌啶形成的大脑中5-氨基戊酸的浓度，这表明5-氨基戊酸是4-氨基丁酸：2-氧代戊二酸转氨酶的体内底物。
