title: Effects of brain ischemia on intermediate filaments of rat hippocampus.
abstract: Neurofilaments subunits (NF-H, NF-M, NF-L) and glial fibrillary acidic protein (GFAP) were investigated in the hippocampus of rats after distinct periods of reperfusion (1 to 15 days) following 20 min of transient global forebrain ischemia in the rat. In vitro [14Ca]leucine incorporation was not altered until 48 h after the ischemic insult, however concentration of intermediate filament subunits significantly decreased in this period. Three days after the insult, leucine incorporation significantly increased while the concentration NF-H, NF-M, and NF-L were still diminished after 15 days of reperfusion. In vitro incorporation of 32P into NF-M and NF-L suffered immediately after ischemia, but returned to control values after two days of reperfusion. GFAP levels decreased immediately after ischemia but quickly recovered and significantly peaked from 7 to 10 days after the insult. These results suggest that transient ischemia followed by reperfusion causes proteolysis of intermediate filaments in the hippocampus, and the proteolysis could be facilitated by diminished phosphorylation levels of NF-M and NF-L.
authors.affiliation: Departamento de Bioquímica, IB--UFRGS (Campus Central), Porto Alegre, RS, Brazil.
authors.forename: M
authors.initials: M
authors.lastname: Camargo-De-Morais
authors.forename: M
authors.initials: M
authors.lastname: De Freitas
authors.forename: A G
authors.initials: AG
authors.lastname: De Mattos
authors.forename: N
authors.initials: N
authors.lastname: Schröder
authors.forename: A C
authors.initials: AC
authors.lastname: Zilles
authors.forename: C S
authors.initials: CS
authors.lastname: Lisboa
authors.forename: N
authors.initials: N
authors.lastname: Arteni
authors.forename: A
authors.initials: A
authors.lastname: Barlem
authors.forename: R
authors.initials: R
authors.lastname: Schierholt
authors.forename: G
authors.initials: G
authors.lastname: Zwetsch
authors.forename: C A
authors.initials: CA
authors.lastname: Souza
authors.forename: R
authors.initials: R
authors.lastname: Pessoa-Pureur
authors.forename: C A
authors.initials: CA
authors.lastname: Netto
mesh_terms: D000818:Animals; D002250:Carbon Radioisotopes; D003598:Cytoskeletal Proteins / Q000378:metabolism; D005904:Glial Fibrillary Acidic Protein / Q000096:biosynthesis*; D006624:Hippocampus / Q000378:metabolism*; D002546:Ischemic Attack, Transient / Q000378:metabolism*; D007700:Kinetics; D007930:Leucine / Q000378:metabolism; D016900:Neurofilament Proteins / Q000378:metabolism*; D010761:Phosphorus Radioisotopes; D011865:Radioisotope Dilution Technique; D051381:Rats; D017208:Rats, Wistar; D015424:Reperfusion; D013997:Time Factors
chemical_list: D002250:Carbon Radioisotopes; D003598:Cytoskeletal Proteins; D005904:Glial Fibrillary Acidic Protein; D016900:Neurofilament Proteins; D010761:Phosphorus Radioisotopes; C044882:neurofilament protein L; C051774:neurofilament protein H; C061195:neurofilament protein M; D007930:Leucine