There is increasing evidence that the
sodium-calcium exchanger (NCX) subtypes, NCX1, NCX2 and NCX3 play an important role in intracellular
calcium homeostasis/dysregulation following
cerebral ischemia. In the present study we examined NCX1, NCX2 and NCX3
protein levels in the rat hippocampus at 3, 6, 12, 18, 24 and 48 h following a 3 min and 8 min duration of global
cerebral ischemia. We observed that
NCX1 protein levels were significantly increased by 22.3% and 20.6% at the 6 and 12 h respective time points following a 3 min duration of global
ischemia, while NCX2 and NCX3
protein levels remained relatively constant. Following a 8 min duration of global
ischemia,
NCX1 protein levels remained relatively constant, while NCX2
protein levels were down-regulated by 6.9%, 10.8%, 14.4% and 10.3% at the 6, 18, 24 and 48 h respective time points, and NCX3
protein levels were up-regulated by 22.1% at the 18 h time point. Taken together, our results show that NCX subtype
protein expression is sensitive to
cerebral ischemia, and indicates that changes in NCX activity may be playing an important role in
calcium maintenance and neuronal outcome following
ischemia.