Robert D. Reynolds
2
, Patricia A. Deuster
3
. College of Business, Cardinal Stritch University,
Milwaukee, WI
5321
7
1
, Department of Human Nutrition and Dietetics, M/C
51
7, University of
Illinois at Chicago, Chicago, IL
2
, Department of Military and Emergency Medicine, Uniformed
Services University of the Health Sciences,
3
.
The initial field study was designed to determine the overall consumption of energy, the
distribution of the macronutrients which provided the energy, and the effects of increasing
altitude on total energy consumption and on changes in energy-providing macronutrients. The 9-
week dietary study included three meals and daily snacks on a 10-day rotation. A detailed record
of energy intake was kept by five subjects who remained in base camp (5300m) and by 10
subjects who climbed to altitudes up to and including the summit of Mt. Everest (8848m). Free
choice of individual items and amounts within the diet was permitted. Intake of food and fluid
was determined by means of monitored entries in 843 daily food records. It is commonly assumed
that there is a natural increase in preference for consumption of higher carbohydrate foods at the
highest altitudes. Contrary to these beliefs, the climbers did successfully self-select an average of
28.5% fat, 55.5% carbohydrate and 14.5% protein. A practical outgrowth of the study was the
derivation of food frequency lists itemizing the top 25 choices in descending order for the five
camps. Energy intake percentages for fat and carbohydrate were also determined for each of these
25 food selections. Upon reviewing the reported food items, it appears that higher fat foods
should not be excluded from the packs of climbers going to higher altitudes. Energy-dense foods
may be encouraged to provide extra energy and alleviate loss of weight.
138.
EFFECTS OF MITOCHONDRIAL PROTEIN SYNTHESIS INHIBITOR ON CYTOCHROME
C OXIDASE ACTIVITY AND ITS SUBUNITS EXPRESSION DURING ACUTE HYPOXIA.
Chen Lifeng
1
, Liu Junze*
2
, Song Rong
3
. Department of Pathophysiology, The Third Military
Medical University, Chongqing, P R China
1
, Department of Pathophysiology, The Third Military
Medical University, Chongqing, P R China *l
2
, Department of Pathophysiology, The Third
Military Medical University, Chongqing, P R China
3
.
The effects of Chloramphenicol (CAP) administration which inhibits mitochondrial protein
synthesis on the cytochrome c oxidase(CytOX) activity and its subunits expression during acute
hypoxia exposure were investigated in cerebral cortex mitochondria. Adult male Wistar rats were
given CAP (50mg/kg, twice a day) for 7 days before sacrificing. Hypoxia was set up by exposing
rats to a hypobaric chamber simulating 5000m high altitude for 24 hours. CytOX activity was
measured by Clark oxygen electrode. CytOX subunits I (CytOX I) and IV (CytOX IV) protein
and mitochondrial transcription factor A (mtTFA) and nuclear respiratory factor-1(NRF-1)
mRNA expression were analyzed by Western-blot and RT-PCR. Our results showed that both
hypoxia exposure and CAP administration both decreased CytOX activity significantly, but
increased after CAP-administered rats hypoxia exposure, although lower than control. CytOX I
protein content and mtTFA and NRF-1 mRNA expression decreased and the ratio of CytOX IV/I
elevated significantly after hypoxia exposure. But CytOX I and CytOX IV/I ratio and mtTFA
mRNA returned to control level when CAP-administered rats exposed to hypoxia. A significant
mutual effect between CAP administration and hypoxia exposure was observed. The protein
content of CytOX IV remained similar in all animals. Although NRF-1 mRNA was still lower
than control after CAP-administered rats hypoxia exposure, no difference was observed between
normal rats hypoxia exposure and CAP-administered rats hypoxia exposure. Our results
concluded that the quantitative regulation of CytOX subunits expression might be a mode in the
control of CytOX activity to some degree during acute hypoxia. CAP administration might be
beneficial to the recovering of CytOX activity after hypoxia exposure.
139.
ROLE OF HSP70 IN THE CROSS-ADAPTATION TO HYPOXIA AND ITS MECHANISM.
Qian Ling-Jia
1
, Wang Xi-Xing
1
, Ren Con-Yu
1
. Institute of Health and Environmental Medicine,
Tianjin, China
1
.
