[Use of gamma-aminobutyric acid from various sources in the synthesis of homocarnosine in the brain of animals of various ages].

The dynamics and intensity of radiolabelled carbon incorporation from [14C] putrescine into homocarnosine in the brains of rats of various age have been studied. In the brains of 1-, 7-, and 2-day-old rats putrescine is the main GABA source for homocarnosine synthesis. In the brains of 14- and 31-day-old animals the GABA formed from glutamic acid participates in homocarnosine synthesis alongside with putrescine. In the brains of adult rats the rate of [14C] incorporation from glutamic acid into homocarnosine is 7 times as low as that of [14C] incorporation from putrescine.