Objective      To investigate the effect of 5-(hydroxymethyl)-2-furfural (5-HMF)

hemoglobin allosteric agent

on the hemoglobin-oxygen affinity and hypoxia resistance capacity.       Methods      Adult SD male rats were randomly divided into a plain blank group

a high altitude blank group

a plain administration group and a high altitude administration group. 5-HMF was intraperitoneally injected into the SD rats at a dose of 50 mg/kg

and the rats were exposed

in a hypoxia chamber for simulating 5 000 m of high altitude environment for 24 h. After 30 min repeated administration

blood was collected from the abdominal aorta to determine blood oxygen saturation (SaO

2

)

partial pressure of carbon dioxide (PaCO

2

)

partial pressure of oxygen (PaO

2

)

HCO

3

-

and oxygen binging curve. Exhaustion swimming time and spatial memory ability of the trained rats were assayed in the presence or absence of 5-HMF under hypoxia or normoxia. Morris water maze was applied to assay spatial memory ability.       Results      5-HMF administration significantly decreased P50 and Hill coefficient under hypoxia or normoxia. Under hypoxia

PaCO

2

SaO

2

PaO

2

HCO

3

-

exhaustion time

target quadrant retention time and frequency across the platform were all decreased significantly compared to those under normoxia. These indicators were all increased significantly after 5-HMF administration under hypoxia

but still lower than those under normoxia

except HCO

3

-

and frequency across the platform. After administration

PaO

2

was increased

and exhaustion time was decreased under normoxia.       Conclusion      5-HMF increases hemoglobin-oxygen affinity

SaO

2

and PaO

2

under hypoxia

and further ameliorates the swimming endurance and spatial memory ability.