1.Without PH
2. EH
3. PH
P1-
2<
P1-
3<
P2-
3<
E/A
1.59±0.1
0.74±0.1
1.17±0.1
0.001
0.05
0.0
01
IVRT, msec
69.9±2.4
106.5±3.4
88.7±3.3
0.001
0.002
0.0
01
DT, msec
147±1.8
190±7.5
170.9±5.
7
0.001
0.004
0.0
51
Legend. E - transmitral flow in early diastole, A - transmitral flow in late diastole, IVRT -
isovolumic relaxation time, DT - deceleration time. Thus in HL with EH significant alterations of
RVDF are observed. But in the presence of PH alterations of RVDF are more pronounced due to
increased right ventricular afterload.
223.
INFLUENCE OF ACUTE HYPOXIA ON RAT BEHAVIOR, ELECTRICAL ACTIVITY OF
BRAIN AND c-AMP CONTENT IN CORTEX OF CEREBRUM. Yanping Tan
1
. Dept. of
Physiology, Qinghai Medical Colledge, PRC
1
.
To explore the influence of acute hypoxia on rat behavior, electrical activity of brain and
cAMP content in cortex of cerebrum, 30 Wistar rats were divided into three groups: 10 rats at
simulated altitude of 5000 m, and 10 rats at 8000 m in a hypobaric chamber for 24 hrs, 10 rats at
the ambient altitude of 2260 m as controls. The record of the electrical activity of the brain was
obtained using a micro-electroencephalography, the measurement of cAMP by immunoassay
method. The results showed that (1) During acute hypoxia, the rats presented loss of appetite,
hypo-movement, dyspnea, and the reaction to sound was weakened, these behaviors were
increased with increasing altitude.(2) As compared with the control group, the frequency and the
amplitude of electric potential waves of the brain was increased 30% and 20% at the 5000 m
hypoxic group, and decreased 20% and 40% at 8000 m hypoxic group, respectively. (3) cAMP
content in cortex of cerebrum was 13 times higher at 5000 m, and 9.6 times higher at 8000 m than
that of the controls. It was 26% less at 8000 m than at 5000 m. The results suggest that the degree
of response to acute hypoxia in rat brain was related to the altitude. The hypoxic damage of the
cerebral cells first occurred at synapses but not at cell body. It seems that cAMP participated in
the reaction of the brain hypoxia.
224.
THE PROTECTIVE EFFECT OF GINGSENG AND GINGKO MIXTURE ON ACUTE
HYPOXIC RATS. Xi-wei Tang
1
, Yan-meng Zhang
1
, Zhong-yuan Shi
1
. Department
1
.
The purpose of this study was to investigate the protective effect of Gingseng and Gingko
mixture on rats under acute decompression hypoxia and its possible mechanism. Adult SD rats
were randomly divided one of three experimental groups: normal oxygen control ( NC), acute
decompression hypoxia (AH) and Gingseng and Gingko mixture add acute decompression
hypoxia (GH). For the later two groups,rats were acutely exposed to simulated 8000m high
altitude in a hypobaric chamber for 7h, water content, Na+, K+-ATPase activity, MDA and LA
concentration, and SOD activity in cerebral tissue were measured. Ginseng and Gingko mixture
administrated to rats orally for 7 days before decompression exposure. The other two groups were
treated with the same volume water. The result of our experiments show that compared to NC
group,cerebral water content was significantly increased in AH group, but it was significantly
reduced in GH group.Na+, K+-ATPase activity in cerebral tissue in AH group was significantly
reduced, while Ginseng and Gingko mixture decreased this reduction. LA.MDA level in AH
group was significantly higher than that of NC group, but this increase was significantly reduced
in GH group. SOD activity tended to drop, but it was not significantly at statistic. SOD activity of
GH group is more higher than that of AH group. That indicate the Ginseng and Gingko mixture
has significant protective effect for acute decompression hypoxia. Its mechanisms are related to
