title: 1-Piperideine as an in vivo precursor of the gamma-aminobutyric acid homologue 5-aminopentanoic acid.
abstract: 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.
mesh_terms: D000596:Amino Acids / Q000032:analysis / Q000378:metabolism*; D021542:Amino Acids, Neutral; D000625:Aminooxyacetic Acid / Q000378:metabolism; D000818:Animals; D001923:Brain Chemistry; D055598:Chemical Phenomena; D002621:Chemistry; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D010880:Piperidines; D011725:Pyridines / Q000032:analysis / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000032:analysis / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D021542:Amino Acids, Neutral; D010880:Piperidines; D011725:Pyridines; D000625:Aminooxyacetic Acid; C043383:1-piperideine; D005680:gamma-Aminobutyric Acid; C013809:5-aminovaleric acid