electron microscopy, the number of type II alveolar epithelial cells was relatively small, but
Kohn's pores were more abundant and slightly larger than those observed in rats. These
morphological features of the yak's lungs seem to represent an outcome of the Yak's adaptation
to hypoxia.
120.
COMPARISON OF PULMONARY VASCULAR RESPONSE TO ENDOGENOUS NITRIC
OXIDE INHIBITION IN SHEEP AND PIGS LIVING AT 2300M. Tomonobu Koizumi
1
,
Zonghai Ruan
1
, Keishi Kubo
1
, Akio Sakai
2
, Takesi Ishizaki
3
, Zhan Wang
4
, Qiu Hong Chen
4
, Xiao
Qin Wang
4
. The First Department of Medicine,Shinshu University School of Medicine, Japan
1
,
Department of Sports Medicine,Shinshu University School of Medicine, Japan
2
, Department of
Fundamental Nursing, Fukui Medical University, Japan
3
, High Altitude Medical Institude of
Qinghai, China
4
.
To compare the role of nitric oxide in the adaptive process to chronic hypoxia, we examined
the effects of endogenous nitric oxide synthase inhibition on pulmonary vascular tone in
conscious sheep and pigs living at high altitude. Unanaesthetized male sheep (n=6) and pigs
(n=5), born and residing in the highlands of Qinghai Province, China (2,300-3,000 m altitude)
were studied at that altitude. Pulmonary, pulmonary artery wedge pressure and cardiac output
were measured. Pulmonary vascular resistance was calculated by (Ppa - Pcwp)/CO. Using a
climatic chamber, hemodynamic measurements during exposures to atmophrenic pressures
corresponding to the altitude of 2,300 m, 0 m, and 4,500 m were performed with and without NO
inhibition, using Nw-nitro-L-argine (20 mg.kg-1), a potent stereospecific competitive inhibitor of
nitric oxide synthase. Ppa and PVR at baseline (2,300 m) and during hypoxic exposure (4,500 m)
in pigs were significantly higher than those in sheep. After NLA administration, Ppa increased
and CO decreased in both animals, resulting in significantly increased PVR at baseline and during
hypoxic exposure. However, there were no significant differences in the % increase in basal or
hypoxic PVR after NLA between sheep and pigs. We conclude that augmented endogenous NO
production could contribute to the regulation of pulmonary vascular tone at high-altitude in sheep
and pigs. However, it is unlikely that NO is responsible for the different pulmonary vascular tone
at basal condition between sheep and pigs at moderate high-altitude.
121.
CORRELATION BETWEEN ECHO AND CATHETERIZATION STUDIES IN A
MEASUREMENT OF PULMONARY ARTERIAL PRESSURE IN KYRGYZ
HIGHLANDERS. Baktybek Kojonazarov
1
, Bakytbek Imanov
2
, Toktosun Amatov
2
, Talant
Sooronbaev
2
, Murat Dadabaev
2
, Mirsaid Mirrakhimov
2
, Nickolas Morrell
3
, Martin Wilkins
4
,
Almaz Aldashev
1
. Institute of Molecular Biology and Medicine, Bishkek, Kyrgyzstan
1
, National
Center of Cardiology and Internal Medicine, Bishkek, Kyrgyzstan
2
, Cambridge University,
Cambridge, UK
3
, Hammersmith Hospital, London, UK
4
.
Background: Evaluation of pulmonary arterial pressure by ECHO has been an important
clinical problem for many years. Aim: To estimate reliability Doppler - ECHO method of
definition of mean PAP by determination of right ventricular outflow tract acceleration time
(AcT) and in diagnostics high-altitude pulmonary hypertension (HAPH) in comparison with
catheterization study. Materials and methods: Forty-six highlanders aged 17-72 years
(47.04±2.38), were studied in National Center in Bishkek (760 meter above sea level). The
methods used were clinical examination, lung function tests, ECG, Doppler ECHO,
catheterization of pulmonary artery. Ultrasound studies were performed using a commercial
available "Acuson Sequoia 256" ultrasound system with 2.5 MHz transducer. All highlanders
were subjected to diagnostic artery catheterization within 24 hour after noninvasive study.
Results: Among 46 highlanders in noninvasive study 25 had pulmonary hypertension and 21 had
a normal mean PAP level. Mean PAP was 31.28±1.33 mm Hg in 25 highlanders with HAPH and
19.28±0.76 mm Hg in 21 health highlanders. In four of 21 highlanders with normal level of mean
PAP on the data Doppler - ECHO is transferred in-group of patients with HAPH. Thus, in group
of patients with HAPH have come 29 person (26 men and 3 women) at which mean PAP was
