Ofulue A F, Matsui R, Thurlbeck W M
Department of Pathology, Faculty of Medicine, University of British Columbia, Vancouver, Canada.
Pediatr Pulmonol. 1993 Mar;15(3):145-50. doi: 10.1002/ppul.1950150304.
Compensatory lung growth after pneumonectomy is a well established phenomenon in young humans and experimental animals. To date, the cellular initiating and/or regulatory factor(s) responsible for this growth response have yet to be established. We have studied changes in lung content and activity of calmodulin, a calcium-dependent regulatory protein in relation with lung mass and DNA content during postpneumonectomy compensatory lung growth in 4-week-old rats. We observed that after left pneumonectomy, right lung calmodulin content (measured by radioimmunoassay) and calmodulin activity (measured by cyclic nucleotide phosphodiesterase activation) were increased at days 1 and 2 after surgery in the pneumonectomized rats, preceding the increase of lung mass and DNA content which started at day 3. Treatment of the pneumonectomized rats with a highly specific calmodulin antagonist, trifluoperazine, immediately after the surgery, resulted in diminished lung calmodulin activity, sparing the calmodulin content, and in concomitant reduction of lung mass and DNA content to values intermediate between those of controls and the pneumonectomized animals. Based on these findings, we conclude that calmodulin may be an important intracellular (possibly, autocrine) initiatory or facilitatory factor in compensatory hyperplastic lung growth after pneumonectomy.
肺切除术后的代偿性肺生长在年轻人类和实验动物中是一种已被充分证实的现象。迄今为止，负责这种生长反应的细胞起始和/或调节因子尚未确定。我们研究了4周龄大鼠肺切除术后代偿性肺生长过程中，钙调蛋白（一种钙依赖性调节蛋白）的肺含量和活性与肺质量和DNA含量的变化关系。我们观察到，左肺切除术后，肺切除大鼠术后第1天和第2天，右肺钙调蛋白含量（通过放射免疫测定）和钙调蛋白活性（通过环核苷酸磷酸二酯酶激活测定）增加，早于第3天开始的肺质量和DNA含量增加。术后立即用高度特异性钙调蛋白拮抗剂三氟拉嗪治疗肺切除大鼠，导致肺钙调蛋白活性降低，钙调蛋白含量不受影响，并使肺质量和DNA含量同时降低至对照组和肺切除动物之间的中间值。基于这些发现，我们得出结论，钙调蛋白可能是肺切除术后代偿性增生性肺生长中的一种重要的细胞内（可能是自分泌）起始或促进因子。
