title: Effects of neonatal cerebral hypoxia-ischemia on the in vitro phosphorylation of synapsin 1 in rat synaptosomes.
abstract: Synapsins are phosphoproteins related to the anchorage of synaptic vesicles to the actin skeleton. Hypoxia-ischemia causes an increased calcium influx into neurons through ionic channels gated by activation of glutamate receptors. In this work seven-day-old Wistar rats were submitted to hypoxia-ischemia and sacrificed after 21 hours, 7, 30, or 90 days. Synaptosomal fractions were obtained by Percoll gradients and incubated with 32P (10 microCi/g). Proteins were analysed by SDS-PAGE and radioactivity incorporated into synapsin 1 was counted by liquid scintillation. Twenty-one hours after hypoxia-ischemia we observed a reduction on the in vitro phosphorylation of synapsin 1, mainly due to hypoxia, rather than to ischemia; this effect was reversed at day 7 after the insult. There was another decrease in phosphorylation 30 days after the event interpreted as a late effect of hypoxia-ischemia. No changes were observed at day 90. Our results suggest that decreased phosphorylation of synapsin 1 could be related to neuronal death that follows hypoxia-ischemia.
authors.affiliation: Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: M B
authors.initials: MB
authors.lastname: Moretto
authors.forename: A
authors.initials: A
authors.lastname: de Mattos-Dutra
authors.forename: N
authors.initials: N
authors.lastname: Arteni
authors.forename: R
authors.initials: R
authors.lastname: Meirelles
authors.forename: M S
authors.initials: MS
authors.lastname: de Freitas
authors.forename: C A
authors.initials: CA
authors.lastname: Netto
authors.forename: R
authors.initials: R
authors.lastname: Pessoa-Pureur
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D015153:Blotting, Western; D002545:Brain Ischemia / Q000378:metabolism* / Q000473:pathology; D016923:Cell Death; D005260:Female; D002534:Hypoxia, Brain / Q000378:metabolism* / Q000473:pathology; D008297:Male; D010766:Phosphorylation; D051381:Rats; D017208:Rats, Wistar; D016704:Synapsins / Q000378:metabolism*; D013574:Synaptosomes / Q000378:metabolism*
chemical_list: D016704:Synapsins