中高海拔地区藏族低氧通气反应的特征

Characteristics of hypoxic ventilatory response in Ti-betan living at moderate and high altitudes.

对居住在海拔２０００～３０００ｍ（中海拔）和４０００～４７００ｍ（高海拔）地区藏族的低氧（１２％Ｏ＿２）及运动通气反应进行了测定。结果：中、高海拔组的低氧通气反应斜率（ΔＶ＿Ｅ／ΔＳａＯ＿２）分别为０．８１±０．０７和０．４６±０．０４Ｌ／ｍｉｎ／％Ｓａｏ＿２（Ｐ＜０．０１），最大运动通气量（Ｖ＿（ｍａｘ））分别为７８．３±３．５和６８．２±２．１Ｌ／ｍｉｎ（Ｐ＜０．０５）。ΔＶ＿Ｅ／ΔＳａＯ＿２和Ｖ＿（Ｅｍａｘ）之间呈现正相关，其回归式分别为ｙ＝４７．０±３７．３Ｘ，ｒ＝０．７０和ｙ＝５３．８±３１．４Ｘ，ｒ＝０．６７。高海拔组最大心率（ＮＲ＿（ｍａｘ））明显低于中海拔组（Ｐ＜０．０１）。本研究提示，中海拔组对低氧的刺激反应保持较高的通气反应，而高海拔组则显示钝化。因此，高原人通气反应的钝化与居住的海拔高度有关。

Hypoxic and exercises ventilatory responses mea-sured in Tibetan who lived at moderate (2000 ～ 3000m ,M-Tibetan) and high (4000～ 4700m, H-Tibetan) alti-tude areas. The result showed that the slope of hypoxicventilatory response (HVR ; V_E/SaO_2) in M- and H-Ti-betan was 0.81 ± 0. 07 and 0. 46± 0. 04 L/ min/%SaO_2( P< 0. 01 ) and the maximal exercise ventilation(V_(Emax)) was 78. 3± 3. 5 and 68. 2± 2. 1 L/min (P<0. 05) , respectively. There were positive correlation be-tween ΔV_E/ΔSaO_2 and V_(Emax) , which y= 47. 0 ± 37. 3x ,r=0. 70 in M-Tibetan, and y= 53. 8±31. 4x, r= 0. 67in H-Tibetan. Maximal heart rate of the H-Tibetan wassignificantly lower than that in the M-Tibetan (P<0. o1). It is suggested that the attenuation of HVR de-pends on the magnitude of the hypoxic stimulus. There-fore, there are differences even among the highaltitudenatives in ventilatory response to hypoxia, e. g. normalrespiratory sensitivity to hypoxia in moderate-altitudenatives, and blunted in high-ahitude natives.