Effects of carbon monoxide on hypoxia inducible factor-1 expression in hypoxia preconditioned mice

AIM:To study the effect of carbon monoxide (CO) on hypoxia inducible factor-1α(HIF-1α) expression and on hypoxic tolerance duration in hypoxia preconditioned mice. METHODS:Mice were injected with normal saline (NS) or hemin intraperitoneally. Western blot was used to detect HIF-1α in hippocampus. The tolerant duration of each hypoxic run was recorded. RESULTS:After 1 and 2 runs of hypoxia exposure, there were no significant differences in HIF-1α expression and hypoxic tolerance duration between N and hemin injection groups. After 3 and 4 runs of hypoxia exposure, the content of HIF-1α was lower and hypoxic tolerance duration was shorter (P＜0.05) in hemin injection groups than that in NS injection groups. CONCLUSION:CO could decrease the expression of HIF-1α, and decrease hypoxic tolerance duration in hypoxia preconditioned mice. The mechanism may be that CO binds to hemoprotein and inhibits hemoprotein oxygen sensor.