Catecholamine metabolism in neonatal rat brain during asphyxia and recovery.

摘要: Infant rats were subjected to various degrees of asphyxia — 1-day-old exposed 100% N2 for 20 min and 4-day-old 94%N2-6%O2 30 min. The activity tyrosine hydroxylase, the first rate limiting enzyme in catecholamine (CA) synthesis, was studied vivo whole brain parts by measuring accumulation dihydroxyphenylalanine (DOPA) after inhibition aromatic L-aminoacid decarboxylase with NSD 1015. Measurements endogenous levels tyrosine, dopamine (DA) noradrenaline (NA) also made during recovery. During there a decrease DOPA animals striatum, midbrain brainstem regions rats. In recovery phase both increased approximately 2-fold anoxia. regional study, significant increase compared controls only noted striatum region. After 2 h, had reached normal or subnormal levels. no changes DA NA anoxia except an 6 h phase. disappearance but not hypoxia retarded H 44/68 (α-methyltyrosine), indicating reduced nerve impulse central dopaminergic noradrenergic nerves. neurotransmitters are ascribed lot important functions mature brain. As cause profound metabolism these transmitters neonatal period, this might be relevant as factor underlying early childhood behavioural neurological disorders.