Rannels D E, White D M, Watkins C A
J Appl Physiol Respir Environ Exerc Physiol. 1979 Feb;46(2):326-33. doi: 10.1152/jappl.1979.46.2.326.
The rapidity with which lung growth was initiated following pneumonectomy was investigated using rats (330 g) in which lung weight-to-body weight ratio and lung cell size had stabilized. Following removal of the left lung, right lung weight increased from 823 to 1.161 mg within 7 days. Right lung weight in sham-operated animals did not change significantly. At day 7, right lung weight-to-body weight ratio in pneumonectomized rats was equal to that of both lungs in sham-operated animals; these values remained equal through day 14. Growth of individual lobes of the right lung was generally in proportion to their initial weights. Dry-to-wet weight ratio in either lung of sham-operated or pneumonectomized animals was unchanged, as compared to unoperated controls. Total right lung RNA and protein increased significantly by day 2 and reached levels equal to those in both lungs of sham-operated animals by day 7. Synthesis of lung proteins, estimated during 120 min of perfusion in situ, was elevated 25% on day 3. Incorporation of [3H]thymidine into DNA increased somewhat on day 2 and was elevated fourfold on day 3, corresponding with the initial accumulation of total DNA within the lung. These observations suggested that increased cell size may accompany early compensatory growth following pneumonectomy, but that the major portion of the response involved cellular hyperplasia.
利用肺重量与体重比及肺细胞大小已稳定的大鼠（330克），研究了肺切除术后肺生长启动的速度。切除左肺后，右肺重量在7天内从823毫克增加到1161毫克。假手术动物的右肺重量没有显著变化。在第7天，肺切除大鼠的右肺重量与体重比与假手术动物双肺的该比值相等；这些值在第14天前一直保持相等。右肺各叶的生长通常与其初始重量成比例。与未手术的对照相比，假手术或肺切除动物任一肺的干重与湿重比均未改变。右肺总RNA和蛋白质在第2天显著增加，并在第7天达到与假手术动物双肺相等的水平。在原位灌注120分钟期间估计的肺蛋白质合成在第3天提高了25%。[3H]胸苷掺入DNA在第2天略有增加，在第3天增加了四倍，这与肺内总DNA的初始积累相对应。这些观察结果表明，肺切除术后早期代偿性生长可能伴随着细胞大小的增加，但反应的主要部分涉及细胞增生。
