In order to clear the role of testosterone in acclimatization processes to altitude 12 healthy
male volunteers subjects 20 25 years old, native of sea level were studied and taken to
Huancayo city (3280 m), where they stayed for five days. A blood sample from forearm was
taken two days before the journey and on days 1, 3 and 5 on high altitude, assessing serum
testosterone by RIA with the use of commercial kits. At the same time arterial oxygen saturation
(%SO2) by pulse oximetry, pulse rate, respiratory rate, blood pressure and hematocrit were
measured. There was no increase observed in serum testosterone levels reported on previous
research by our group and other researchers in subjects taken to altitudes over 4000 m. We
observed a significant decrease in the values of %SO2 on the high altitude in relation to sea level,
not finding correlation between testosterone values and %SO2 values. We found significant
differences in values of blood pressure and hematocrit on the fifth day of exposure. In subjects
taken to Huancayo (3280 m) it was not possible to demonstrate that testosterone plays a role on
acclimatization, this possibly happening on altitudes over 4,000 m where it was reported an
increase on serum testosterone levels.
163.
THE RELATION OF PLASMA TISSUE FACTOR (TF) WITH EXCESSIVE
POLYCYTHEMIA AT HIGH ALTITUDE. Sun Nai-Tong
1
. Dept. of Hematology, Qinghai
Medical College Hospital, Xining, Qinghai, P.R. China
1
.
High altitude Polycythemia is a common problem among high altitude residents, and the
pathophysiology of which is unclear. The aim of the study was to determine any relation of
plasma tissue factor (TF) with an excessive polycythemia at high altitude. Methods_The
concentrations of plasma TF were measured by solid phase sandwich enzyme-linked-
immunosorbent assay (ELISA) in 20 patients with high altitude polycythemia (HAPC)_20
Tibetan natives and 33 acclimatized Han new comers at altitude of 4300. Among Han new
comers, 19 have lived at 4300m for over one year, and 14 have lived at 4300m for less than one
month. In addition, the plasma TF was also measured in 15 subjects who were living at 2260m
(Xining) as a moderate altitude control group. Results: The concentrations of plasma TF in
patients with HAPC (447.7±173.5 pg/ml) were significantly higher than that of the Tibetan
natives (219.3±53.6pg/ml), acclimatized Han newcomers (285.6±54.5pg/ml), and control group
(176.9±46.5pg/ml). There was positive correlation between plasma TF and Hb in the patients
with HAPC (r=0.608, P<0.001), and negative correlation between plasma TF and blood platelet
(r= -0.862, P<0.001). Conclusion: The expression of plasma TF was significantly elevated in
patients with HAPC when compared with the control group; suggesting that the higher level of
TF can induce angiogenesis and improved oxygenation, hence delaying the development of
HAPC. On the other hand, TF activated coagulation can lead to hypercoagulation, which may
induced microcycle blocking, thus it can exaggerate the development of HAPC. The degrees of
TF influence in the two sides are different in the various phases of hypoxia.
164.
THE PARADOXICAL RELATIONSHIP BETWEEN SHORTENING OF VOLUNTARY
BREATH-HOLDING TIME (VBHT) AT HIGH ALTITUDE AND URINARY PH. Michiro
Nakashima
1
, Shoji Maeda
2
, Masayoshi Nishimura
3
, Shigeru Masuyama
4
. Takaori Hospital,
Kyoto, JAPAN
1
, Maeda Acupuncture Clinic, Osaka
2
, Rakuto High School, Kyoto
3
, Chiba
University, Medical School
4
.
The author has studied the phenomenon that breath-holding time (VBHT) was shortened with
increasing of altitude since 1970. And one of these observations was reported at the 13th Hypoxia
Symposium in Banff, Canada in Feb.2003, on which it was suspected that this phenomenon might
come from renal regulation of respiratory alkalosis. However, this suspicion was confused by the
paradoxical observation of this time. Material and Method: VBHT and pH of urine harvested just
after the "braking point" of breath-holding of 7 high school students in the normobaric-hypoxic
room were observed Result: With the increasing of altitude ( in this investigation, the decreasing
of O2 concentration) the VBHT decreased at first, then, increased a little, decreased again, and
again increased a little, drawing wave. Though urinary pH revealed the tendency of increasing
