Hill J M
J Cell Biol. 1975 Jan;64(1):260-5. doi: 10.1083/jcb.64.1.260.
The degradation rates of kidney rRNA labeled before UNI or sham are unchanged 5 days after the operations (t one-and-a half, 88 h). Therefore, there is no contribution from pre-existing rRNA to the increased amount of rRNA in the stimulated kidney. After labeling with L-(methyl-3H)methionine, the kinetics of incorporation into rRNA precursors, 10-60 min and at the postoperative times of 4, 16, 36, and 96 h. The specific activity of cytoplasmic rRNA after 1-h labeling with L-(methyl-3H)methionine increased occured at 4 or 96 h. Since (a) the rate of degradation of rRNA, (b) the kinetics of incorporation and processing of rRNA precursors, and (c) the rate of RNA synthesis appear unchanged after UNI, the accretion of rRNA must involve decreased degradation of newly synthesized rRNA.
单侧肾切除(UNI)或假手术后5天(1.5个半衰期,88小时),术前标记的肾rRNA降解率未发生变化。因此,刺激后的肾脏中rRNA增加量并非来自预先存在的rRNA。用L-(甲基-³H)甲硫氨酸标记后,研究了在术后4、16、36和96小时,10 - 60分钟内rRNA前体的掺入动力学。用L-(甲基-³H)甲硫氨酸标记1小时后,细胞质rRNA的比活性在4小时或96小时出现增加。由于(a)rRNA的降解率,(b)rRNA前体的掺入和加工动力学,以及(c)RNA合成速率在单侧肾切除后似乎未发生变化,rRNA的增加必定涉及新合成rRNA降解的减少。