(PAEC) and smooth muscle cells (PASMC) in this blunting of HPV. METHODS: PAEC and
PASMC were cultured in normoxia (control group, CG) or in hypoxia (Chronic hypoxia group,
CHG) until 6th subculture, then the responses to acute hypoxia were measured. RESULTS: 1.
The responses of PAEC in CG and CHG to acute hypoxia: 1) [Ca2+]i was increased more in
CHG than in CG; 2) cAMP was decreased more in CHG than in CG, while cGMP remained
unchanged in CG, but increased in CHG; 3) Increment of eNOSmRNA expression was greater in
CHG than in CG; 4) TXSmRNA expression and TXA2 production were increased in CG,
however decreased in CHG; 5) ET-1mRNA expression was increased more in CHG than in CG.
2. The responses of PASMC in CG and CHG to acute hypoxia: 1) [Ca2+]i was increased more in
CG than in CHG; 2) cAMP and cGMP were decreased in CG, while increased in CHG; 3) COX-
2mRNA expression was increased more in CHG than in CG; 4) Expression of potassium channels
Kv1.3, Kv2.1 and Kv3.1mRNA were increased in CG, while decreased in CHG; 5) As compared
to CG, the percentage of hypoxia sensitive cells was decreased and the intermediate cells were
increased in CHG. CONCLUSION: Chronic hypoxia can change the responses of PAEC and
PASMC to acute hypoxia, which may take part in the blunting of hypoxic pulmonary
vasoconstriction.
31.
EFFECTS OF COMPOUND DANGSHEN CAPSULE ON ACUTE MOUNTAIN SICKNESS.
Zhang Dong-Xiang
1
, Zhang Yan-Kun
1
, Ma Yan
1
, Xie Yin-Zhi
1
, Zhang Xi-Zhou
1
, Cui Jian-Hua
1
.
Institute of Hygiene and Environmental Medicine, Academy of Military Medical Science,
Tianjin
1
.
Objective: To investigate the effects of compound Dangshen capsule on acute mountain
sickness (AMS) in young volunteers at 5300m altitude and to provide a highly effective drug for
prevention of AMS. Methods: The subjects were divided randomly into compound Dangshen
tablet (CDT, n=13) group, compound Dangshen capsule (CDC, n=18) group and control (Con,
n=14) group. Each time, 2 capsules were taken in both CDC and Con groups while 6 tablets were
taken in CDT group. All the subjects took the medicine 2 times a day. The subjects began to take
the medicine for 5 days before they entered high altitude. Their SaO2 and HR were observed
regularly before and while taking the medicine. Then they continued to take the medicine for 5
days during the journey to high altitude,and for 7 days after arrival. During this period, symptoms
of AMS were assessed every other day and pharmacodynamic appraisal was taken at the same
time. Results: The effects of CDC on AMS are superior to the other groups while the dosage of
CDC is only 1/9 of that of CDT. From the fifth day, SaO2 of CDC and CDT was obviously
higher than that of the Con (p<0.05).Among three groups, HR all decreased, but there was no
difference between them (p0.05). Conclusion The effects of CDC on acute mountain sickness are
obvious. It can be taken along conveniently and its dosage is lower than that of CDT. So it is
expected that CDCwill replace CDT--the traditional anti-hypoxia drug.
32.
CORTICOTROPIN-RELEASING FACTOR RECEPTOR TYPE
1
AND
2
MRNA EXPRESSION
IN THE RAT ANTERIOR PITUITARY IS MODULATED BY INTERMITTENT HYPOXIA,
COLD AND RESTRAINT. Ji-Zeng Du
1
. Zhejiang University
1
.
We had previously demonstrated that continual hypoxia stimulated corticotropin-releasing
factor (CRF) release and CRF mRNA in the hypothalamus, and enhanced plasma ACTH as well
as corticosterone of rats. This study demonstrated that CRF receptor 1 (CRF R1) and CRF
receptor 2 (CRF R2) mRNA in the rat anterior pituitary were changed by intermittent hypoxia,
cold, restraint and in combination, using in situ autoradiograph. Rats were exposed to simulated
intermittent altitude hypoxia for 4h/d for various periods in a hypobaric chamber. The hypoxia of
2km (16.0% O2) or 5km (10.8% O2) caused both CRF R1 and R2 mRNA changes, in a biphasic
manner, with significant decline for 1d and enhancement after 2d. CRF R2 mRNA at 5km for 1d
was markedly decreased and increased for 2d, 5d. 5km hypoxia markedly reduced body weight
gain. The increased CRF R1 mRNA was induced by restraint, intermittent hypoxia,
hypoxia+restraint and hypoxia+cold respectively except for sole cold. The CRF R2 mRNA was
