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BioMed Research International
Volume 2015, Article ID 720250, 5 pages
Research Article

Blunted Activation of Rho-Kinase in Yak Pulmonary Circulation

1Department of Fundamental Nursing and Medicine, University of Fukui, Fukui 910-1193, Japan
2Department of Respiratory Medicine, Kanazawa Medical University, Ishikawa 920-0265, Japan
3Department of Health Science, Matsumoto University, Matsumoto 390-1295, Japan
4Life Science Research Laboratory, University of Fukui, Fukui 910-1193, Japan
5Laboratory of Molecular and Cell Biology, Institute of Molecular Biology and Medicine, 720040 Bishkek, Kyrgyzstan
6Excellence Cluster Cardio-Pulmonary System, Universities of Giessen & Marburg Lung Center, 35392 Giessen, Germany
7Department of General Surgery, Kyrgyz State Medical Academy, 720020 Bishkek, Kyrgyzstan
8Department of Internal Medicine, University of Fukui, Fukui 910-1193, Japan

Received 12 August 2014; Revised 17 October 2014; Accepted 24 October 2014

Academic Editor: Harm Jan J. Bogaard

Copyright © 2015 Takeshi Ishizaki et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Yaks have adapted to high altitude and they do not develop hypoxic pulmonary hypertension. Although we previously identified the important role of augmented nitric oxide synthase activity in the yak pulmonary circulatory system, evidence of the direct involvement of Rho-kinase as a basal vascular tone regulator is lacking. Four domesticated male pure-bred yaks and four bulls that were born and raised at an altitude of 3000 m in the Tien-Shan mountains were studied at an altitude of 3,100 m. Mean pulmonary artery pressure (mPAP) was measured before and after fasudil (60 mg in 20 mL of saline) was intravenously administered using a Swan-Ganz catheter at a rate of 3.3 mL/min for 30 min. Fasudil decreased mPAP in bulls from to  mmHg () after 15 min and the level was maintained for 30 min, but it merely blunted mPAP in yaks from to and  mmHg after 5 and 30 min, respectively. These findings comprise the first evidence of a modest role of Rho-kinase in the maintenance of pulmonary artery pressure in the yak.