induced a decrease in parasympathetic and increase in sympathetic tone which tended to be
reversed with acclimatization. Sildenafil had no deleterious effects on the cardiovascular response
to high altitude exposure and its control by the autonomic nervous system.
28.
THE BLOCKING EFFECT OF NALOXONE ON DECREASED MAP INDUCED BY
HYPOXIA IN RABBITS. Xu Cun-He
1
, Wang Jian-Xin
2
, Meng Xian-Fa
2
, He Jia-Qiang
2
. The
Affiliated Hospital of Qinghai Medical College, Xining, Qinghai, P.R. China
1
, Dept. of
Physiology, Qinghai Medical College, Xining, Qinghai, P. R.China
2
.
This paper reports the effects of naloxone injected in the fourth ventricle on the circulatory
response to acute hypoxia. Rabbits were anesthetized with urethane and chloralose, immobilized
with gallamine triethiodide and ventilated artificially. The animals were divided into two groups:
the control group with an injection of physiological saline (100_l) and the experimental group
with injection of naloxone (40_g/100_l) at the fourth ventricle. Heart rate (HR) and mean arterial
pressure (MAP) in the control group significantly decreased during acute hypoxia, and then
returned to the normal level 5-10 min after normoxia. HR in the experimental group was
remarkably decreased during acute hypoxia and recovered after normoxia. MAP in the
experiment group did not showed significant change during acute hypoxia. These results suggest
that the decreased MAP during hypoxia was mediated by the depressant effect of endogenous
opioid peptides around the area of the fourth ventricle.
29.
RISK FACTORS FOR PREVALENCE OF DIABETES MELLITUS AT
3
700M . Xu Cun-He
1
,
Zhang Jian-Guo
1
, Dai Qing-Xiang
1
, Zhang Hui-Li
1
, Ma Ming-Fu
1
, Li Jun
1
, Gao Ji-Dong
1
. The
Affiliated Hospital of Qinghai Medical College, Xining, Qinghai, P.R. China
1
.
The risk factors for development of diabetes mellitus (DM) and impaired glucose regulation
(IGR) should be investigated. Methods: 1049 Tibetan and 446 Han residents (761 male, 734
female) aged 13-84 at an altitude of 3700m in the Guoluo region were studied. DM and IGR
(IGT/IFG) were diagnosed based on the 1998 WHO diagnosis criteria. Waist circumference
(WC), blood pressed (BP), and vocation were determined. Results 1.Total prevalence of DM,
IGR was 2.5% and 2.1% respectively, lower than 3.21% (DM) and 4.76 (IGT) at sea level in
1996. Logistic regression analysis for development of DM and IGR showed that the probability
(p) was increased with the male gender, mental labor vocation, increased age, and increased WC.
2. The prevalence of DM and IGR in different groups is shown in Table 1.
Table 1. Prevalence comparison in different groups (%) (*P<0.05, **P<0.01)
Group
DM
IGR
Sex (male/female)
3.7/1.4 **
3.2/1.1*
Age(45y/<45y)
6.7/1.2**
4.5/1.4*
Vocation (mental labor/manual labor)
3.9/1.6*
3.9/0.9**
WC(male)(85cm/<85cm)
5.9/2.4*
5.1/1.8**
WC(female)(80cm/<80cm)
1.3/1.4
1.3/1.0
Conclusion 1.The prevalence of DM and IGR in high altitude is significantly lower than that
of sea level. 2. Male gender, over 45 years age, decreased physical exercise, and abdominal
obesity are risk factors for development of DM and IGR at high altitude.
30.
CHRONIC HYPOXIA CHANGED THE RESPONSIVENESS OF PULMONARY ARTERIAL
ENDOTHELIAL AND SMOOTH MUSCLE CELLS TO ACUTE HYPOXIA. Wang Di-Xun
1
.
Department of Pathophysiology, Tongji Medical College, Huazhong University of Science and
Technology
1
.
AIM: The blunting of hypoxic pulmonary vasoconstriction (HPV) is an adaptation to chronic
hypoxia, which may reduce the incidence and severity of high altitude pulmonary hypertension
and heart disease. The aim is to investigate the role of pulmonary arterial endothelial cells
