Deoxyribonucleic acid synthesis in lung cells during compensatory lung growth after pneumonectomy.

To understand the cellular events associated with compensatory lung growth, we evaluated deoxyribonucleic acid synthesis and autoradiographs of right lungs from mice killed 1 hour after injection of thymidine labeled with hydrogen-3 in studies performed 1 to 14 days after left pneumonectomy. Total lung deoxyribonucleic acid synthesis was increased by postoperative day 3, reaching a peak by day 6. Deoxyribonucleic acid synthesis in liver and kidney did not increase during this period, illustrating that the growth stimulus was lung specific. Increased deoxyribonucleic acid synthesis, as judged by autoradiographs, appeared in pleural mesothelial cells by postpneumonectomy day 1; in interstitium, endothelium, and peripheral alveoli by postpneumonectomy day 3; and in the bulk of alveoli by postpneumonectomy day 6. Labeling of pleural, interstitial, and endothelial cells was maximal within the first postoperative week at 7.8, 5.2, and 1.3 per cent of cells, respectively, and decreased toward control values ther...