Dunsmore S E, Lee Y C, Rannels D E
Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey 17033, USA.
Am J Physiol. 1997 Jul;273(1 Pt 1):L86-92. doi: 10.1152/ajplung.1997.273.1.L86.
Previous work suggested an association between changes in the alveolar extracellular matrix and epithelial cell growth in lungs of adrenalectomized rats in vivo. Other studies demonstrated that adrenal hormones modulate extracellular matrix synthesis by type II pulmonary epithelial cells in vitro. Adrenal hormone regulation of type II cell fibronectin synthesis was thus examined. Fibronectin synthesis was quantitated by immunoprecipitation of the metabolically labeled molecule from cells, extracellular matrix, and culture medium. On day 1 of primary culture, synthesis of matrix fibronectin by type II cells isolated from the lungs of adrenalectomized animals was more than twice that by cells isolated from control rats. Adrenalectomy elevated steady-state fibronectin mRNA levels in primary isolates of type II cells cultured for 1 or 3 days. These results suggest that altered fibronectin synthesis and deposition into the extracellular matrix accompany changes in type II cell phenotype that occur after adrenalectomy.
先前的研究表明，在体内肾上腺切除的大鼠肺中，肺泡细胞外基质的变化与上皮细胞生长之间存在关联。其他研究表明，肾上腺激素在体外可调节II型肺上皮细胞的细胞外基质合成。因此，对肾上腺激素对II型细胞纤连蛋白合成的调节作用进行了研究。通过对细胞、细胞外基质和培养基中代谢标记分子进行免疫沉淀来定量纤连蛋白的合成。在原代培养的第1天，从肾上腺切除动物的肺中分离出的II型细胞合成的基质纤连蛋白是从对照大鼠分离出的细胞的两倍多。肾上腺切除术使培养1天或3天的II型细胞原代分离物中纤连蛋白的稳态mRNA水平升高。这些结果表明，肾上腺切除术后II型细胞表型发生变化的同时，纤连蛋白合成和向细胞外基质中的沉积也发生了改变。
