Comparison of the composition and content of pulmonary surfactant among plateau zokors, plateau pikas and rats / 生理学报

ABSTRACT

In the present study, the composition and content of pulmonary surfactant (PS) were analyzed to explore the hypoxia adaptation mechanism in plateau zokors (Myospalax baileyi) and plateau pikas (Ochotona curzoniae). 36 plateau zokors and plateau pikas were trapped alive at the Laji Mountain in Guide County, Qinghai Province (at the altitude of about 3 600 m), and 36 Sprague-Dawley (SD) rats were purchased from the experimental animal center of Lanzhou University (at the altitude of about 1 500 m). All animals were lavaged after laboratory anesthesia, the blood in lung tissues was fully washed out and the lung tissues were then taken out to obtain the bronchoalveolar lavage fluid by bronchoalveolar lavage. The composition and content of phospholipids in the PS of three different kinds of animals were analyzed by using high performance liquid chromatography; the protein composition, content and types in the PS were analyzed by G-250 Coomassie brilliant blue method, polyacrylamide gel electrophoresis (PAGE) and mass spectrometry; the dissolved oxygen in the PS solutions were determined by using dissolved oxygen electrode. The results showed that the total contents of phospholipids in the PS were successively increased among plateau zokors, plateau pikas and SD rats (P 0.05). The relative content of PSe had no significant differences between plateau zokors and plateau pikas (P > 0.05), but both were significantly higher than that of SD rats (P < 0.01). The serum albumin (SA) was identified in the PS of three kinds of animals, including homologous tetramer protein containing heme, which is composed of hemoglobin β subunit, in plateau zokors and plateau pikas. Immunoglobulin (Ig) heavy chain was found in PS of plateau zokors and SD rats. The content of Ig heavy chain in plateau zokor was significantly higher than that in SD rats (P < 0.01), and the content of protein containing heme was significantly higher than that in plateau pikas (P < 0.05). The amount of dissolved oxygen was successively decreased in the PS among plateau zokors, plateau pikas and SD rats (P < 0.01), but it was significantly higher than that in saline (P < 0.01). These results suggest that the total content of proteins in the PS of plateau zokors and plateau pikas was significantly higher, while the total content of phospholipids was significantly decreased. There were high content of homologous tetramer protein containing heme in the PS of plateau zokors and plateau pikas. The relative content of DPPC, the main component of phospholipids, was significantly increased in plateau zokors. The changes of PS component and content improve the adaptability of the two plateau animals in hypoxia environment.