Beinlich C J, Vitkauskas K J, Morgan H E
Hood Research Program/Weis Center for Research, Pennsylvania State University, Danville 17822, USA.
J Mol Cell Cardiol. 1998 Jul;30(7):1263-74. doi: 10.1006/jmcc.1998.0704.
The differential rate of growth of the left-ventricular free wall (LVFW) and the right-ventricular free wall (RVFW) of the newborn pig has been studied by measuring the rates of ribosome formation and protein synthesis in the isolated perfused heart. These measurements are limited by the heterogeneity of the cells and the stability of the preparation. The hypothesis of the present study was that isolated cultured myocytes would offer much less cellular heterogeneity and a more prolonged period to explore the actions of anabolic agents. The rate of [3H] phenylalanine incorporation into total protein during 24 h of culture was established as a monitor of the rate of protein synthesis in myocytes and was found to be 64 and 61% of the rates measured in the LVFW and RVFW, respectively, of the perfused heart. The relative rates of protein synthesis in LVFW and RVFW were the same in myocytes and perfused hearts. Myocytes from the LVFW had increased rates of protein synthesis after exposure to a combination of norepinephrine and propranolol or endothelin for 24 h. Exposure to endothelin for 3 days increased rates of protein synthesis to a greater extent in LVFW myocytes than in RVFW myocytes. In LVFW myocytes from enalapril-treated pigs or in LVFW myocytes exposed to 40 mM KCl, angiotensin II increased the rate of protein synthesis by 14% during the third day of incubation. These studies indicated that cultured myocytes reflected the rates of protein synthesis observed in LVFW and RVFW of the perfused piglet heart. Differential effects of an alpha-adrenergic agonist, endothelin and angiotensin II in LVFW as compared to RVFW myocytes was observed. In each case, the response to the agonist was decreased or absent in RVFW as compared to LVFW myocytes.
通过测量新生猪离体灌注心脏中核糖体形成速率和蛋白质合成速率，研究了左心室游离壁（LVFW）和右心室游离壁（RVFW）的差异生长速率。这些测量受细胞异质性和制剂稳定性的限制。本研究的假设是，分离培养的心肌细胞将提供少得多的细胞异质性和更长的时间来探索合成代谢剂的作用。将[3H]苯丙氨酸在24小时培养期间掺入总蛋白的速率确定为心肌细胞中蛋白质合成速率的监测指标，发现其分别为灌注心脏LVFW和RVFW中测量速率的64%和61%。LVFW和RVFW中蛋白质合成的相对速率在心肌细胞和灌注心脏中是相同的。LVFW的心肌细胞在暴露于去甲肾上腺素和普萘洛尔或内皮素的组合24小时后，蛋白质合成速率增加。暴露于内皮素3天，LVFW心肌细胞中蛋白质合成速率的增加程度大于RVFW心肌细胞。在经依那普利治疗的猪的LVFW心肌细胞或暴露于40 mM KCl的LVFW心肌细胞中，血管紧张素II在孵育第三天使蛋白质合成速率增加了14%。这些研究表明，培养的心肌细胞反映了灌注仔猪心脏LVFW和RVFW中观察到的蛋白质合成速率。观察到α-肾上腺素能激动剂、内皮素和血管紧张素II对LVFW心肌细胞与RVFW心肌细胞的不同作用。在每种情况下，与LVFW心肌细胞相比，RVFW对激动剂的反应降低或不存在。
