increased at high altitude. Inflammatory cytokines could be involved in the inflammation reaction
to high altitude environment stress.
21.
A STUDY OF ENDOTHELIN AND CALCITONIN GENE-RELATED PEPTIDE LEVELS IN
NORMAL MALES AT DIFFERENT ALTITUDES. Teng Chang-Qing
1
, Zhu Ai-Qin
1
, Lou
Ming-Yuan
1
, Zhou Jing-Ping
1
, Li Chun-Jie
1
. Department of Geriatrics, Qinghai Provincial
Hospital, Qinghai.
Purpose: To evaluate the levels of endothelin (ET) and calcitonin gene-related peptide
(CGRP) in normal men at different high altitudes. Methods: Three groups of subjects, all healthy
male workers building the Qinghai-Tibetan railroad were studied: 60 subjects from 4,680m
(Yiangshiping); 55 subjects from 2807m (Ge Ermu) and 70 subjects from 2260m (Xining).
Plasma levels of ET and CGRP were measured by radioimmunoassay. Results: ET was
significantly higher in workers in Yianshiping (108.02±3.86), compared to the groups in Ge Ermu
(92.15±2.39pg/ml) and in Xining (85.33±1.79pg/ml, p<0.01). ET was also higher in Ge Ermu
than that in Xining (p<0.05). In these groups, there is an increase in the level of ET with
increasing altitude. CGRP was significantly decreased in normal workers at 4680m
(321.42±24.96pg/ml) as compared to those at 2807m and 2260m (401.89±18.7pg/ml and
467.87±23.71pg/ml), respectively (p<0.01). In the Ge Ermu and Xining groups, CGRP exhibited
a decline with altitude as well (p<0.05). These findings indicate that ET and CGRP levels depend
on altitude. Our results imply that endothelial cells may secrete a large amount of ET during
altitude hypoxia; however, the abnormal changes of ET may have overwhelmed the regulating
ability of CGRP. Therefore, CGRP decreased with hypoxia of altitude.
22.
COMPARISON OF THE EFFECTS OF HYPOXIA AND CNTF ON THE PROLIFERATION
OF RAT MYOBLASTS IN VITRO. Xiaoping Chen
1
, Tong Zhao
2
, Lingling Zhu
2
, Haitao Wu
2
,
Ming Fan
2
. Institute of Space Medico-Engineering
1
, Department of Brain Protection and
Plasticity, Institute of Basic Medical Sciences
2
. Beijing, China
2
. ?? See below
Objective: To find a better way to enhance myoblast proliferation, we compared the effects of
hypoxia and ciliary neurotrophic factor (CNTF) on the in vitro proliferation of myoblasts isolated
from skeletal muscle of neonatal rats. Methods: (1) myoblasts of neonatal rat were isolated by a
new method built in our lab (2) The hypoxia-treated cells were cultured in lowered (3%, 10%) O2
for 3 days while the CNTF-treated cells were cultured in 5% concentration of CNTF for 3 days.
(3) The proliferating ability of myoblasts was examined by immunocytochemistry for Desmin
and Myf5 and Western Blot for differentiation of markers (myogenin, p21). Results: (1) The rate
of Desmin-positive cells isolated by our new method from the skeletal muscle of neonatal rat was
high- up to 97%. Thus, it is an excellent culture system to study the effect of exogenous factors
on the primary myoblasts in vitro. (2) The number of Desmin-positive cells cultured in 3% and
10% O2 for 3 days was 1.5 and 2.5 times more than in 20% O2 respectively, while the number of
Desmin-positive cells with CNTF-treated for 3 days was only ~1.1 times more than without
CNTF-treated. (3) Western Blot analysis indicated that the expression level of Myf5 and Desmin
in the CNTF-treated cells was only ~0.9 times more than in the untreated cells, while the
expression level of myogenin and p21 in the CNTF-treated cells was 3.2 times lower than in the
untreated cells. Conclusions: Hypoxic exposure is a more effective way to enhance myoblast
proliferation in vitro than CNTF treatment. Hypoxia may provide a new way to amplify
myoblasts for clinic therapy without expensive growth factor. The work was supported by High
Technology Project of China (2003AA2050042002BA711A0), key grant of Natural Sciences
Foundation of China (30393130) and key grant of Natural Sciences Foundation of Beijing
(7021002)
23.
CLONING AND TISSUE EXPRESSION OF THREE OXYGEN-BINDING AND OXYGEN-
TRANSFERRING PROTEINS IN OCHOTONA CURZONIAE (PIKA) AT HIGH ALTITUDE.
