TY - JOUR
T1 - Reduced activity of the pyruvate dehydrogenase complex but not cytochrome c oxidase is associated with neuronal loss in the striatum following short-term forebrain ischemia
AU - Zaidan, Emad
AU - Sims, Neil R.
PY - 1997/10/24
Y1 - 1997/10/24
N2 - Previous studies have identified changes in the activities of the pyruvate dehydrogenase complex (PDHC) and cytochrome c oxidase during early recirculation following short-term cerebral ischemia. However, the relationship of these changes to the delayed selective neuronal loss that develops as a result of short-term ischemia is incompletely defined. The effects of ischemia and recirculation on the activities of these enzymes in the dorsolateral striatum, a region containing many susceptible neurons, and the ischemia-resistant paramedian cortex have been compared. No significant loss of activity of cytochrome c oxidase was seen in either region during the first few hours of recirculation following 30 min of ischemia. A decrease (of 32%) was observed at 24 h in the dorsolateral striatum. However, this probably resulted from changes in the mitochondrial fraction due to advanced neuronal degeneration. By contrast, there was a significant decrease (by 24%) in activity of PDHC at 3 h following a 30-min, but not a 10-min, ischemic period. Only the 30-min ischemic period resulted in extensive delayed neuronal loss. In the paramedian cortex, there was no significant change in PDHC and no neuronal loss following either ischemic period. These results provide strong evidence for a close association between neuronal loss and changes in the activity of PDHC but not cytochrome c oxidase in the dorsolateral striatum.
AB - Previous studies have identified changes in the activities of the pyruvate dehydrogenase complex (PDHC) and cytochrome c oxidase during early recirculation following short-term cerebral ischemia. However, the relationship of these changes to the delayed selective neuronal loss that develops as a result of short-term ischemia is incompletely defined. The effects of ischemia and recirculation on the activities of these enzymes in the dorsolateral striatum, a region containing many susceptible neurons, and the ischemia-resistant paramedian cortex have been compared. No significant loss of activity of cytochrome c oxidase was seen in either region during the first few hours of recirculation following 30 min of ischemia. A decrease (of 32%) was observed at 24 h in the dorsolateral striatum. However, this probably resulted from changes in the mitochondrial fraction due to advanced neuronal degeneration. By contrast, there was a significant decrease (by 24%) in activity of PDHC at 3 h following a 30-min, but not a 10-min, ischemic period. Only the 30-min ischemic period resulted in extensive delayed neuronal loss. In the paramedian cortex, there was no significant change in PDHC and no neuronal loss following either ischemic period. These results provide strong evidence for a close association between neuronal loss and changes in the activity of PDHC but not cytochrome c oxidase in the dorsolateral striatum.
KW - Cytochrome c oxidase
KW - Ischemia
KW - Mitochondria
KW - Neuronal death
KW - Pyruvate dehydrogenase complex
KW - Selective vulnerability
UR - http://www.scopus.com/inward/record.url?scp=0030771096&partnerID=8YFLogxK
U2 - 10.1016/S0006-8993(97)00833-0
DO - 10.1016/S0006-8993(97)00833-0
M3 - Article
C2 - 9406951
AN - SCOPUS:0030771096
VL - 772
SP - 23
EP - 28
JO - Brain Research
JF - Brain Research
SN - 0006-8993
IS - 1-2
ER -