Ischemia-induced inhibition of the initiation factor 2alpha phosphatase activity in the rat brain.
Rats were subjected to the standard four-vessel occlusion model of brain transient ischemia for 30 min. Following different recirculation periods, the level of phosphorylation of the initiation factor 2 subunit alpha (eIF2alpha) and the eIF2alpha kinase/s and phosphatase/s activity were determined. eIF2alpha phosphorylation significantly increased very early during reperfusion (10-30 min), recovering at 4 h of reperfusion. Activation of any eIF2alpha kinases studied during ischemia or reperfusion was not noted. Conversely, eIF2alpha phosphatase activity significantly decreased at 10-15 min of reperfusion, reaching values even higher than in controls at 2-4 h of reperfusion. Our results support the hypothesis that the reperfusion-induced phosphorylated eIF2alpha changes are at least a result of the transiently eIF2alpha phosphatase inhibition.
Martín de la Vega
C
C
Departamento de Investigación, Hospital Ramón y Cajal, Madrid, Spain.
Burda
J
J
Salinas
M
M
D000818:Animals; D002546:Ischemic Attack, Transient / Q000201:enzymology*; D008297:Male; D019579:Neocortex / Q000201:enzymology; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D010766:Phosphorylation; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000201:enzymology; D019892:eIF-2 Kinase / Q000378:metabolism
D019892:eIF-2 Kinase; C019363:eIF-2 phosphatase; D010749:Phosphoprotein Phosphatases