high altitude areas, and make a rational nutrition plan. Method:,Subjects: road construction
workers at three heights, under 3000m, 3000~4000 and over 4000 meters. We measured
atmosphere factors, labour intensity, and the state of nutrition. Results: The atmosphere
conditions among different high altitudes shows a dry climate, low humidity, and
windiness.Negative balance was shown of energy consumption and intake for road maintenance
workers at different altitudes. The nutrition lack illness among the workers who do construction
and maintenance of roads at the high altitude and the increasing percent of vitamin C in the urine
was lower than the normal population. Conclusions: The labour intensity is higher for workers at
high altitude area. The meal construction is not reasonable, the food is monotonous. Intake of
nutrition is lacking, and nutrition lack illness rate is higher than normal.
295.
EFFECTS OF HYPOXIA ON THE RHEOLOGIC PROPERTIES OF LEUKOCYTES IN RATS.
Gang Zhang
1
, Yuqi Gao
1
. Department of Pathophysiology and High Altitude Physiology, Third
Military Medical University, Chong
1
.
The rheologic properties of leukocyte obviously affect the microcirculation, however, effect
of hypoxia on the rheologic properties of leukocyte has not been determined. This study was
designed to explore the effects of acute and chronic hypoxia on the rheological properties of
leukocytes in rats. Hypobaric chamber was used to simulate high altitude condition to reproduce
animal hypoxic model. Adult Wistar rats were randomized in three groups: control, acute hypoxia
(5000m 3days) and chronic hypoxia (5000m 30 days). Intravital microscopy and computer image
analysis system were used to evaluate the rheologic properties of leuckcytes in mesentery
microcirculation. We found that rheological properties of leukocytes were changed obviously in
acute hypoxia, rolling velocity slowed, number of leukocytes adherence on endothelium
increased, TLECT (total leukocyte-endothelium contact time) obviously extended, but these
change were not distinct in chronic hypoxia. Compared with the control, the expression of CD18
of PMN detected by flow cytometry was significantly increased in hypoxia, but scope of CD18
increasing in chronic hypoxia was less than that in acute hypoxia. Using micropipette aspiration
technology and a three-element standard linear solid model, we found that rigidity of leukocytes
in hypoxic group increased significantly, and passive deformability decreased. Furthermore, the
length of pseudopod of PMN in hypoxic group formed inside the micropipette stimulated by
hypoxic blood serum was obviously longer than corresponding value of control; this suggested
hypoxia might advance PMN chemotaxis and migration. Results suggested that hypoxia has a
strong impact on the rheological properties of leukocyte and this may be one of the important
mechanisms of endothelium damage revoked by hypoxia (By grant of NSFC 39730190 and
30393131).
296.
PERFORMANCES OF LEARNING AND MEMORY OF POSTNATAL DEVELOPMENT
MICE IN WATER MAZE AND 8-ARM RADIAL MAZE IMPROVED BY INTERMITTENT
HYPOXIA* . Jia-Xing Zhang
1
, Xue-Qun Chen
1
, Ji-Zeng Du
1
, Qing-Mei Chen
1
. Zhejiang Univ.
1
.
Hypoxia was commonly reported to impair learning and memory of either human or animals.
In this paper, we demonstrated that an intermittent hypoxia (IH) improved learning and memory
of postnatal development mice. Spatial learning and memory was tested in Morris water maze
(MWM) task from postnatal (P) day 36(P36) to P40 and from P85 to P89, and in 8-arm maze
from P60 to P68 after variant duration of IH. Following birth, the newborn mice were
immediately exposed to a simulated IH at altitude of 2 km or 5 km in a hypobaric chamber for 1,
2, 3 or 4 weeks, respectively. In addition, P36 mice exposed to 4-week hypoxia were used for
testing LTP and CREB. The results showed that, the escape latencies in MWM of P36 mice,
treated with IH for from 1 to 4 weeks, were markedly decreased, and the retention time was
significantly enhanced. Meanwhile, the emotional adaptation to novel situations was to be
facilitated. The enhanced amplitude of LTP, numbers of synapse and phosphorylated cAMP-
responsive element binding protein (p-CREB) were found in mice exposed to 4-week of IH at
2km or 5km. The number of error choices in 8-arm maze task showed a significantly decrease in
