ascended to Lahsa (3658m altitude) by airplane. The PWC170 and the symptom scores of AMS
were evaluated. Results:Oxygen saturation at sea level was reduced to 80% during the exercise of
IV group. After ascending to high altitude, PWC170 had no significant decrease, while PWC170
in other three groups decreased significantly (P<0.05). The incidences of AMS was 4/30, 6/30,
6/30 and 1/30 in group I to IV respectively. Conclusion: Hypoxia preconditioning combined with
exercise prevents the decrement of PWC170 after ascending to high altitude quickly. (By grant of
01L062).
49.
COMPARISON STUDY ON HIF-1 ALPHA IN TIBETAN AND HAN UMBILICAL VENOUS
ENDOTHELIAL CELLS. Wenxiang Gao
1
, Yuqi Gao
1
, Guobing Zhang
1
, Ling Song
1
, Bingyong
Sun
1
. Department of Pathophysiology and High Altitude Physiology, Third Military Medical
University, Chong
1
.
Tibetans have been considered the best adapted to the high altitude hypoxic environment. To
explore the molecular adaptive mechanisms of Tibetans and investigate the role of hypoxia
inducible factor 1 (HIF-1), a key factor in mediating hypoxic responses, we compared the
expression of HIF-1_ mRNA and protein, as well as two HIF-1-target genes (VEGF and iNOS) in
cultured umbilical venous endothelial cells (UVECs) from native Tibetan and immigrant Han.
UVECs were collected and cultured under hypoxic (0.5% oxygen) or normoxic conditions for 2h,
4h, 12h and 24h. The mRNA levels of HIF-1_, VEGF and iNOS mRNA and the protein level of
HIF-1_ were determined with RT-PCT and Western blot, respectively. HIF-1_ mRNA was
constitutively expressed in Tibetan UVECs under normoxic condition, and remained constant
after hypoxic exposure. In contrast, HIF-1_protein underwent dynamic changes in cultured
Tibetan UVECs in response to hypoxia. Concurrent with induction of HIF-1_ protein, VEGF and
iNOS mRNA expression were up-regulated by hypoxia in Tibetan UVECs. UVECs derived from
immigrant Han exhibited identical expression patterns under normoxic and hypoxic condition as
Tibetan's UVECs for HIF-1_ mRNA and protein, as well as VEGF and iNOS mRNAs. Our
findings suggest that there is no race difference in HIF-1_ transcription and HIF-1 mediated
adaptive responses to high altitude in native Tibetans and immigrant Hans. (By grant of NSFC
39730190 and 30393131)
50.
MODERATE EXERCISE AT SIMULATED HIGH ALTITUDE INCREASES SENSITIVITY
OF GLUCOSE TRANSPORT TO INSULIN . Yuqi Gao
1
, Jiang Huang
1
. Department of
Pathophysiology and High Altitude Physiology, Third Military Medical University, Chong
1
.
Objective: To investigate the effects of moderate exercise under hypobaric hypoxia on
glucose transporters and glucose uptake response to insulin.Methods: Wistar rats were divided
into four groups: SS raised at sea level, SE(swimming 1h/d, 6d/week, 5weeks, at sea level,),
HS(raised at simulated 5000m altitude, 5weeks), HE(swimming at 4000m, 1h/d and then ascent
to 5000m altitude 23h/d, 6d/week, 5weeks). Skeletal muscle from hind limb and cerebral cortex
were collected. The glucose uptake rate GUR,the level of glucose (G), glycogen(Gn), phosphate
creatine(PCr), ATP and lactate(LA) were assayed. The expression of protein and mRNA of
GLUT1, 4 in skeletal muscle membrane and GLUT3 in cerebral cortex were detected by ELISA
and RT-PCR, respectively. Results In skeletal muscle, the PCr, LA, Gn or G showed no
difference between HE and HS. In cerebral cortex, the PCr, Gn, and G in HE were same as in HS,
but LA in HE was significantly higher than HS. The GUR of skeletal muscle was lower in HE
than in HS. The increased glucose uptake rate stimulated by insulin in skeletal muscle was the
strongest in HE(HE: 8.17, HS: 5.38, SS: 2.45, SE: 2.75 pmol/mg/min). The expression of
GLUT1, 4 in skeletal muscle and GLUT3 in cerebral cortex in HE were increased by 25%, 39%,
and 19% respectively, compared with HS. The level of GLUT3 mRNA in HE was higher than
HS(119.88±14.42% vs 99.03±12.56%, p<0.05), while the level of GLUT1, 4 mRNA in HE was
similar with HS. Conclusion: Moderate exercise under hypoxia upregulates expression of glucose
transporters and increases the sensitivity of glucose transport to insulin, which may facilitate
glucose uptake. (By grant of NSFC 39730190 and 30393131).
