Rannels D E, Karl H W, Bennett R A
Department of Physiology, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey 17033.
Am J Physiol. 1987 Oct;253(4 Pt 1):E343-8. doi: 10.1152/ajpendo.1987.253.4.E343.
The effects of adrenalectomy and/or in vivo treatment with hydrocortisone acetate (HCA;5 mg X kg-1 X day-1) on lung growth were investigated in control and pneumonectomized rats of 250 g body wt. Left pneumonectomy (day 0) initiated rapid hyperplastic growth of the right lung, which was unaffected by HCA. Similarly, HCA had no effect on lung growth in unoperated control animals. Two weeks after pneumonectomy, right lung dry mass, protein, RNA, and DNA were equal to that in both lungs of unoperated rats. Adrenalectomy 5 days before (day -5) left pneumonectomy increased the rate and extent of right lung growth, but did not change its hyperplastic character. Continuous HCA treatment (days -5 to 14) prevented the adrenalectomy-mediated increase in postpneumonectomy lung growth. "Early" HCA dosing (days -5 to 6) of adrenalectomized-pneumonectomized animals suppressed lung growth to the pneumonectomy level, but from days 7 to 14 growth accelerated to the adrenalectomized-pneumonectomized rate. Conversely, "late" HCA, initiated when adrenalectomized-pneumonectomized animals had restored normal total lung mass (days 6 to 14), quickly reduced right lung growth to rates typical of unoperated controls. The latter effects were not observed unless continuous steroid treatment was provided throughout this interval. The data support a role for glucocorticosteroids in modulation of the accelerated compensatory lung growth initiated by partial resection of the tissue.
在体重250克的对照大鼠和肺切除大鼠中，研究了肾上腺切除术和/或醋酸氢化可的松（HCA；5毫克×千克⁻¹×天⁻¹）体内治疗对肺生长的影响。左肺切除术（第0天）引发了右肺的快速增生性生长，HCA对此无影响。同样，HCA对未手术的对照动物的肺生长也无影响。肺切除术后两周，右肺干质量、蛋白质、RNA和DNA与未手术大鼠双肺的相应指标相当。在左肺切除术之前5天（第 -5天）进行肾上腺切除术，增加了右肺生长的速率和程度，但未改变其增生特性。连续HCA治疗（第 -5天至第14天）可防止肾上腺切除术介导的肺切除术后肺生长增加。对肾上腺切除-肺切除动物进行“早期”HCA给药（第 -5天至第6天）可将肺生长抑制至肺切除水平，但从第7天至第14天生长加速至肾上腺切除-肺切除速率。相反，当肾上腺切除-肺切除动物恢复正常肺总质量时（第6天至第14天）开始的“晚期”HCA，可迅速将右肺生长速率降低至未手术对照的典型速率。除非在此期间提供持续的类固醇治疗，否则不会观察到后一种效应。这些数据支持糖皮质激素在调节由组织部分切除引发的加速代偿性肺生长中起作用。
