title: Activity of synaptosomal ATP diphosphohydrolase from hippocampus of rats tolerant to forebrain ischemia.
abstract: Cerebral ischemia causes cell death of vulnerable neurons in mammalian brain. Wistar adult rats (male and female, weighing 180-280 g) were submitted to 2 min, 10 min, or to 2 and 10 min (separated by a 24-h interval) of transient forebrain ischemia by the four-vessel occlusion method. Animals subjected to the longer ischemic episodes had massive necrosis of pyramidal CA1 cells of the hippocampus, while animals receiving double ischemia (2 + 10 min) showed neuronal tolerance to the ischemic insult. ATP-diphosphohydrolase activity from hippocampal synaptosomes was assayed in these three groups (N = 6 animals/group) under two conditions: no reperfusion and 5-min of reperfusion. The control values for ATPase and ADPase activities were 144.7 +/- 18.8 and 60.6 +/- 5.24 nmol Pi min-1 mg protein-1, respectively. The 10-min group without reperfusion showed an enhancement of approximately 20% for ATPase and ADPase activities. In reperfused rats, only the 2-min group had a 20% increase in both enzymatic activities. We suggest that modulation of ATP-diphosphohydrolase activity might be involved in molecular events that follow both ischemia and reperfusion.
authors.affiliation: Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil.
authors.forename: M R
authors.initials: MR
authors.lastname: Schetinger
authors.forename: C K
authors.initials: CK
authors.lastname: Barcellos
authors.forename: A
authors.initials: A
authors.lastname: Barlem
authors.forename: G
authors.initials: G
authors.lastname: Zwestch
authors.forename: A
authors.initials: A
authors.lastname: Gubert
authors.forename: C
authors.initials: C
authors.lastname: Bertuol
authors.forename: N
authors.initials: N
authors.lastname: Arteni
authors.forename: R D
authors.initials: RD
authors.lastname: Dias
authors.forename: J J
authors.initials: JJ
authors.lastname: Sarkis
authors.forename: C A
authors.initials: CA
authors.lastname: Netto
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D001081:Apyrase / Q000378:metabolism*; D005260:Female; D006624:Hippocampus / Q000201:enzymology*; D002546:Ischemic Attack, Transient / Q000201:enzymology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D015424:Reperfusion; D013574:Synaptosomes / Q000201:enzymology*; D013997:Time Factors
chemical_list: D000251:Adenosine Triphosphatases; D001081:Apyrase