Research on High-altitude Adapted Animal Models

在这个项目中，进行了三项研究。第一项研究是比较三种哺乳动物对高海拔的敏感性.使用成年雄性Sprague道利（SD，n=10）大鼠、Suncs（n=5）和Pika（n=6）。与SD大鼠相比，鼠兔右心室重量/左心室重量比值（RVW/LVW）、红细胞压积（Ht）和肺小动脉中膜平滑肌均显著降低。而SD大鼠与Suncs之间无明显差异。第二，比较不同品系大鼠对高原的敏感性.本研究选用6个品系的大鼠，即LEW SSN（n=7）、F344/N（n=7）、WM/MS（N=3）、WKAH/HOK（n=7）、WF/N（n=3）和SD（N=27）。为了研究这六种大鼠在肺血管控制方面的潜在差异，我们在离体灌流肺中测量了对急性肺泡缺氧（3%O_2）或注射血管紧张素2的压力反应。结果表明，F334/N对急性肺泡缺氧的压力反应最小，WKAH/HOK对急性肺泡缺氧的压力反应最大。第三，为了研究冷暴露对低氧肺压力反应的影响，我们研究了冷暴露大鼠肺灌流压力反应和常温下的压力反应。大鼠肺对缺氧的压力反应在冷暴露后即刻明显低于对照值，但在冷暴露后12小时内开始增加，并在冷暴露停止后3d达到最大值。增加是时间依赖性的。

In this project, three studies were performed. First study was to investigate the comparison of susceptibility to high - altitude among three mammalian species. Adult male Sprague Dawley( SD,n=10 )rats, Suncs( n=5 )and Pika( n=6 )were used. The ratio of right to left ventricular weight ( RVW/LVW ), haematocrit ( Ht ) and smooth muscle in media of pulmonary arterioles in Pikas showed significantly low values compared with SD rats. But not differences were observed between SD rats and Suncs. Second, the comparison of susceptibility to high - altitude among rat strains were examined. In this study, six strains of rat i e LEW SSN( n=7 ), F344/N( n=7 ), WM/MS( N=3 ), WKAH/HOK( n=7 ), WF/N( n=3 )and SD( N=27 )were used. To investigate potential differences in lung vascular control among these six rat strains, we measured the pressure response to acute alveolar hypoxia(3%O_2 )or angiotensin 2 injection in isolated perfused lungs. As the result, F334/N showed smallest pressure response to acute alveolar hypoxia and WKAH/HOK showed biggest response to hypoxia. Third, to investigate the effects of cold - exposure on pulmonary pressure response to hypoxia, we studied pressure responses in perfused lungs from rat that had been exposed to a cold environment, and those kept at a normal temperature. The pressure responses of rat lungs to hypoxia just after removal from the cold were significantly lower than that control value, bat the responses began to increase within 12 hrs, and reached a maximum 3days after cessation of cold - exposure. The increase was time - dependent.