Adaptation to intermittent hypoxia seems potentially beneficial in clinical medicine and
sports. But, the mechanisms of muscle tissue adaptation to intermittent hypoxic training (IHT)
remain poorly understood. The aim of this study was to investigate the effects of IHT on
mitochondrial respiration, lipid peroxidation, and ultrastructure of skeletal (gastrocnemius)
muscle in rats. Forty Wistar rats were randomized into 2 groups of 20 animals each. In the study
group the rats were exposed to 15 daily sessions of IHT. An IHT session consists of alternating
periods of hypoxia (12-10% O2 in inhaled gaseous mixture) and subsequent reoxygenation
(breathing in ambient air), each period lasted 15 min, 5 periods per each session. The control
group underwent the same training while constantly breathing ambient air. It was shown that the
first session of IHT led to simultaneous augmentation both to the NADH-oxidase and succinate
oxidase pathways of oxidation in muscle mitochondria with an increase of respiratory coefficient
and phosphorylation rate. At the same time, the lipid peroxidation rise was registered. At the end
of IHT, these effects were replaced by a marked activation of NADH-dependent oxidation
pathway and a slight decrease in succinate oxidation pathway with a significant increase in
ADP/O ratio and lipid peroxidation inhibition. After IHT, the muscle mitochondrial and capillary
densities increased compared to control. Mathematical modeling revealed that adaptation to IHT
may be also based on increasing of subsarcolemmal mitochondria content or decreasing of their
affinity to oxygen. So, IHT made the muscle energy metabolism more economic, inhibited the
possibility of lipid peroxidation activation and enhanced oxygen transport in the muscle fiber.
149.
THE STUDY OF THE ANGIOTENSIN-CONVERTING ENZYME GENE POLYMORPHISM
IN HUMANS OF DIFFERENT ETHNICITY AND AT DIFFERENT ALTITUDES . Yu Man-
Tang
1
, Wang Xiao-Qing
1
, Chen Qiu-Hong
1
, Liu Shi-Ming
1
, Wu Tian-Yi
1
. Qinghai Province
Institute of High-Altitute Medical Science Research, Xining, China
1
.
Angiotensin-converting enzyme (ACE) has recently been implicated in the development of
high altitude pulmonary hypertension. The aim of present study is to investigate ACE gene
frequency (ACEGF), ACE gene type frequency (ACEGTF) of people at high altitude and sea
level, and the relationship between ACEGF, ACEGTF and hypoxia inducible factor gene (HIFG).
We determined the polymorphism of the ACE gene in the serum of 90 adults (three groups of 30,
Han Tibetan and Mongolian, living at 3780m) and 30 Han living at 16m using PCR gene
proliferation, gene sequence measurement on blood sample DNA saline analysis extraction and
primer screening. We determined the ACE gene sequence (ACEGS) in the serum of 3780m
groups using Wistar rats HIFG as a frame of reference. We compared the levels of ACEGF and
ACEGTF in two groups: Tibetan vs. Han and Mongolian at 3780m and three 3780m groups vs.
16m group. No significant differences in the levels of ACEGF among Han, Tibetan and
Mongolian at 3780m were observed (0.6562, 0.6377, 0.6505, respectively, mean, p0.05). There
were great differences in the levels of ACEGF between 16m group with a mean of 0.7186 and
those in three 3780m groups (p<0.05). The levels of ACEGTF (I/I, I/D, D/D) in Han, Tibetan and
Mongolian at 3780m and Han at 16m respectively were: (%, mean) 14, 11, 4; 16, 10, 7; 14, 12, 6
and 5, 3, 26. The ACEGTF in 3780m groups were very close. There were obvious differences in
the ACEGTF between 3780m groups and 16m group (p<0.001). There was ACE gene expression
in Wister HIFG array, 490bp digit in 3780m groups. In conclusion, there were significant
differences in the polymorphism of ACE gene between highlanders and lowlanders. Racial
differences in the polymorphism of ACE gene did not contribute at high altitude. ACE gene
probably plays a role in harmonization of HIFG.
150.
FIVE YEARS FOLLOW UP OF THE DYNAMICS OF PULMONARY CIRCULATION IN
HEALTHY MINERS COMMUTING FROM LOW ALTITUDE TO HIGH ALTITUDE.
Abdirashit Maripov
1
, Almaz Akunov
1
, Akpay Sarybaev
1
, Hans Le Roux
2
, Francois Dutoit
2
,
Mirsaid Mirrakhimov
1
. National Centre of Cardiology and Internal Medicine, Bishkek,
Kyrgyzstan
1
, Medical Service of Kum-Tor Operating Company
2
.
