Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
THE INTRAISCHEMIC AND EARLY REPERFUSION CHANGES OF PROTEIN-SYNTHESIS IN THE RAT-BRAIN - EIF-2-ALPHA KINASE-ACTIVITY AND ROLE OF INITIATION-FACTORS EIF-2-ALPHA AND EIF-4E
Autore:
BURDA J; MARTIN ME; GOTTLIEB M; CHAVKO M; MARSALA J; ALCAZAR A; PAVON M; FANDO JL; SALINAS M;
Indirizzi:
HOSP RAMON Y CAJAL,DEPT INVEST,SERV BIOQUIM,CTRA COLMENAR KM 9 E-28034 MADRID SPAIN HOSP RAMON Y CAJAL,DEPT INVEST,SERV BIOQUIM E-28034 MADRID SPAIN SLOVAK ACAD SCI,INST NEUROBIOL,DEPT NEUROCHEM KOSICE 04001 SLOVAKIA UNIV ALCALA DE HENARES,DEPT BIOQUIM & BIOL MOL E-28871 ALCALA DE HENARES SPAIN UNIV AUTONOMA MADRID,FAC MED,CSIC,CTR NACL BIOTECNOL E-28029 MADRID SPAIN
Titolo Testata:
Journal of cerebral blood flow and metabolism
fascicolo: 1, volume: 18, anno: 1998,
pagine: 59 - 66
SICI:
0271-678X(1998)18:1<59:TIAERC>2.0.ZU;2-F
Fonte:
ISI
Lingua:
ENG
Soggetto:
NUCLEOTIDE-EXCHANGE FACTOR; TRANSIENT CEREBRAL-ISCHEMIA; MONKEY BRAIN; INHIBITION; TRANSLATION; RECOVERY; RNA; PHOSPHORYLATION; RECIRCULATION; MECHANISMS;
Keywords:
TRANSLATION; INITIATION FACTORS; PROTEIN PHOSPHORYLATION; TRANSIENT CEREBRAL ISCHEMIA; EIF-2-ALPHA KINASES;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
45
Recensione:
Indirizzi per estratti:
Citazione:
J. Burda et al., "THE INTRAISCHEMIC AND EARLY REPERFUSION CHANGES OF PROTEIN-SYNTHESIS IN THE RAT-BRAIN - EIF-2-ALPHA KINASE-ACTIVITY AND ROLE OF INITIATION-FACTORS EIF-2-ALPHA AND EIF-4E", Journal of cerebral blood flow and metabolism, 18(1), 1998, pp. 59-66

Abstract

Rats were subjected to the standard four-vessel occlusion model of transient cerebral ischemia (vertebral and carotid arteries). The effects of normothermic ischemia (37 degrees C) followed or not by 30-minutereperfusion, as well as 30-minute postdecapitative ischemia, on translational rates were examined. Protein synthesis rate, as measured in acell-free system, was significantly inhibited in ischemic rats, and the extent of inhibition strongly depended on duration and temperature,and less on the model of ischemia used. The ability of reinitiation in vitro (by using aurintricarboxylic acid) decreased after ischemia, suggesting a failure in the synthetic machinery at the initiation level. Eukaryotic initiation factor 2 (eIF-2) presented almost basal activity and levels after 30-minute normothermic ischemia, and the amount ofphosphorylated eIF-2 alpha in these samples, as well as in sham-control samples, was undetectable. The decrease in the levels of phosphorylated initiation factor 4E (eIF-4E) after 30-minute ischemia (from 32% to 16%) could explain, at least partially, the impairment of initiation during transient cerebral ischemia. After reperfusion, eIF-4E phosphorylation was almost completely restored to basal levels (29%), whereas the level of phosphorylated eIF-2 alpha was higher (13%) than in controls and ischemic samples (both less than 2%). eIF-2 alpha kinase activity irt vitro as measured by phosphorylation of endogenous eIF-2 in the presence of ATP/Mg2+, was higher in ischemic samples (8%) than in controls (4%). It seems probable that the failure of the kinase in phosphorylating eIF-2 in vivo during ischemia is due to the depletion of ATP stores. The levels of the double-stranded activated eIF-2 alpha kinase were slightly higher in ischemic animals than in controls. Our results suggest that the modulation of eIF-4E phosphorylation could be implicated in the regulation of translation during ischemia. On the contrary, phosphorylation of eIF-2 alpha, by an eIF-2 alpha kinase already activated during ischemia, represents a plausible mechanism for explaining the inhibition of translation during reperfusion.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 30/03/20 alle ore 13:23:08