Objective   To investigate the relationship between HS1-associated protein X-1 (HAX-1) expression and neuron apoptosis in rats after global cerebral ischemia reperfusion injury.    Methods   Rats were subjected to global cerebral ischemia reperfusion injury through fourvessel occlusion

and then the experimental rats were divided into 5 groups

normal group (NC)

6

24

48 and 72 h post injury groups (n=5 for each group). Immunohistochemistry and TUNEL were used to detect HAX-1 expression and activated Caspase-3

and cell apoptosis in cortex of rats.    Results   The expression level of HAX1 in ischemic cortex was peaked at 6 h (37.60±3.45)

then decreased at 24

48 and 72 h (11.40±1.14

10.40±1.52

and 9.80±1.30 respectively)

to an extend lower than the normal level (P0.01). The expression of Caspase-3 in ischemic cortex was up-regulated after global cerebral ischemia reperfusion injury in rats with the prolongation of injury time (72.80±5.49

106.20±6.91

129.00±19.74

and 166.20±15.32 respectively for 6

24

48 and 72 h post injury). The number of apoptotic cells was increased obviously with the elapse of time (92.00±9.06

133.80±10.64

157.00±10.83

and 187.80±14.96 respectively for 6

24

48 and 72 h post injury

P0.01).    Conclusion   The expression of HAX-1 reachs a peak in a short time after global ischemia reperfusion injury

suggesting it may be involved in the anti-apoptosis of neuron apoptosis. With the elapse of injury time

its expression is decreased and associated with the increase of apoptotic cells.