| Co-Investigator(Kenkyū-buntansha) |
FUKUSHIMA Masao Dept.of Internal Med.Shinshu Univ., Assistant, 医学部・第一内科学, 助手 (30173339)
KOBAYASHI Toshio Dept.of Internal Med.Shinshu Univ., Assistant Professor, 医学部・第一内科学, 講師 (80020775)
UEDA Gou Dept.of Environmental Physiol.Shinshu Univ., Professor, 医学部・環境生理学, 教授 (10020702)
KUSAMA Shozo Dept.of Internal Med.Shinshu Univ., Professor (70020708)
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| Research Abstract |
Pika (the genus Ochotona), paleontologically proved th be extremely primitive, is one of native high altitude species and the distribution ranged widely from low to high altigudes about 10-6,100m above sea level).In August 1986, we captured the Pikas at Qinghai areas in China, 2.300m(n=13), 3,300m(n=15), and 4,460m(n=14) above sea level and measured some hemodynamic parameters in captured places. In August 1987, we used the low-altitude Pikas (alt 650m. n=10)which had been imported from France to Japan in 1974 and were bred by a Japanese animal company. We measured the pulmonary artery pressure (P<@2PA<@D2), right ventricular witght ratio(RVW/LVW) as an index of the right ventricular hypertrophy, number of red blood cell (RBC), mean cell volume (MCV), hematocrit (HT), blood viscosity, red cell deformability and the oxygen consumption(Vo<@D22@>D2) in the low altitude Pikas. The values were compared with those of rats. The results were as follows:
1) The P_<PA>, RVW/LVW and HT in Pika showed significantly low values compared with those of rats in all altitude ranges.
2) The P_<PA>, RVW/LVW and Ht values increased with altitudes in both Pika and rat, but the extents of increase with altitude in Pikas was respectively less than that of rats.
3) By comparing the low-alltitude Pikas with rats, the values of P_<PA> RVW/LVW.Ht,MCV, blood viscosty, and VO_2 in Pika were shown to be lower than those of rats. The differnces were statistically significant, although no difference was found in RBC and red cell deformability.
Conclusion: The low-altitude pikes also indicated some signs of highaltitude adaptation.
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