We determined the independent effects of hypoxia, glucose deprivation and ischemia (hypoxia plus glucose deprivation) on steady-state levels of MRNA coding for specific nuclear and mitochondrially encoded enzymes of oxidative metabolism in cultured rat neurons and gila. Neither hypoxia nor low glucose alone changed steady-state message levels for any transcript. However, ischemia induced a biphasic effect on mitochondrially encoded transcripts for cytochrome oxidase subunit two (CO2) and the subunits 8 and 6 of ATPase (A 8/6), initially decreasing and then increasing mRNA levels to or above the levels recorded prior to ischemia. In contrast, three nuclear encoded transcripts for mitochondrial proteins were decreased by ischemia. These data demonstrate a lack of coordination between the expression of nuclear and mitochondrial genes in the initial response to ischemia and suggest that a selective, primary reaction to brain cell insults exists within the mitochondrion.
- Oxidative phosphorylation
ASJC Scopus subject areas