肺表面活性蛋白A (Surfactant protein A, SP‐A) 是最丰富的肺表面活性蛋白，由SFTPA基因编码合成，主要在哺乳动物的肺组织中合成，也在骨骼肌等组织中表达。SP‐A具有降低肺表面张力、增强肺气体交换、调节免疫、清除病原体和降低炎症反应的功能。本研究通过对不同海拔SD大鼠 (2 250 m和3 700 m) 和高原鼢鼠 (Eospalax baileyi) (2 700 m和3 700 m) 肝、肺、骨骼肌、小肠、结肠和脂肪组织转录组测序分析后；利用qRT‑PCR法比较分析SFTPA基因在两个物种骨骼肌和肺组织中的表达水平；利用Western Blotting法比较分析SP‐A在两个物种骨骼肌、肺组织和血清中的表达水平。转录组分析发现，随着海拔升高，大鼠骨骼肌中SFTPA基因表达显著上调，但在高原鼢鼠骨骼肌中其表达没有显著差异；qRT‑PCR结果显示，随着海拔升高，生境氧含量下降，SD大鼠骨骼肌组织中SFTPA表达升高，高原鼢鼠骨骼肌组织中SFTPA表达显著降低，且SD大鼠和高原鼢鼠肺组织中SFTPA表达均显著降低；Western Blotting结果显示，随着海拔升高，生境氧含量下降，在SD大鼠和高原鼢鼠骨骼肌、血清和肺组织中SP‐A的表达水平均显著升高。总之，高海拔低氧环境下，SD大鼠和高原鼢鼠肺组织中SFTPA基因转录表达显著降低，但两个物种肺组织中SP‐A含量不仅没有下降，反而显著升高，这可能是由骨骼肌合成并分泌的SP‐A经血液转运至肺组织的结果，也是SD大鼠习服低氧环境，高原鼢鼠适应低氧环境的重要机制。

Pulmonary surfactant protein A (Surfactant protein A, SP-A) is the most abundant pulmonary surfactant protein, encoded and synthesized by the SFTPA gene. SP-A is primarily synthesized in the lung tissue of mammals and is also expressed in tissues such as skeletal muscle. SP-A has functions including reducing pulmonary surface tension, enhancing pulmonary gas exchange, regulating immunity, clearing pathogens, and reducing inflammatory responses. In this study, after performing transcriptome sequencing analysis on the liver, lung, skeletal muscle, small intestine, colon, and adipose tissues from SD rats (2 250 m and 3 700 m) and plateau zokors (2 700 m and 3 700 m) at different altitudes; the expression levels of SFTPA gene in skeletal muscle and lung tissues of the two species were compared and analyzed by qRT-PCR; the expression levels of SP-A in skeletal muscle, lung tissue and serum of the two species were compared and analyzed by Western Blotting. The transcriptome analysis revealed that with increasing altitude, the expression of the SFTPA gene in the skeletal muscle of SD rats were significantly up-regulated, while in the skeletal muscle of plateau zokors, there were no significant difference in its expression; the qRT-PCR results showed that with increasing altitude and decreasing environmental oxygen levels, the expression of SFTPA in the skeletal muscle of SD rats increased, whereas in the skeletal muscle of plateau zokors, the expression of SFTPA significantly decreased. Furthermore, the expression of SFTPA in the lung tissues of both SD rats and plateau zokors were significantly decreased; the Western Blotting results showed that with increasing altitude and decreasing environmental oxygen levels, the expression levels of SP-A in the skeletal muscle, serum, and lung tissues of both SD rats and plateau zokors were significantly increased. In conclusion, in a high-altitude hypoxia environment, the transcriptional expression of the SFTPA gene in the lung tissues of SD rats and plateau zokors were significantly decreased. However, the content of SP-A in their lung tissues not only did not decrease but significantly increased. This may be due to SP-A synthesized and secreted by skeletal muscle being transported to the lung tissues via the bloodstream, representing an important mechanism for SD rats and plateau zokors to adapt to hypoxia environments.