从不同年龄大鼠分离出的肝细胞对各类核糖核酸的转录。

The transcription of various types of ribonucleic acid by hepatocytes isolated from rats of various ages.

作者信息

Richardson A, Birchenall-Sparks M C, Staecker J L, Hardwick J P, Liu D S

出版信息

J Gerontol. 1982 Nov;37(6):666-72. doi: 10.1093/geronj/37.6.666.

DOI:10.1093/geronj/37.6.666

Abstract

The synthesis of various types of ribonucleic acid (RNA) isolated from 6- to 3-month-old female Fischer F344 rats was compared. The rate of RNA synthesis by freshly prepared hepatocytes was determined by dividing the amount of [3H]orotic acid incorporated into RNA as uridine-5'-monophosphate by the specific activity of the uridine-5'-triphosphate pool. The rate of total RNA synthesis by hepatocytes from 19-month-old rats was 40% less than the rate for hepatocytes from 12-month-old rats. No significant difference in the rate of total RNA synthesis was observed between 19 and 30 months of age. The percentage of [3H]orotic acid incorporated into poly(A) + RNA by 30-month-old rats was approximately 50% less than that observed for hepatocytes isolated from 6-month-old rats. The percentage of [3H]orotic acid incorporated into poly(A)-RNA as ribosomal RNA (38S, 18S, and 5S RNAs) or transfer RNA was similar for 12- and 30-month-old rats. The rate of poly(A) + RNA synthesis by hepatocytes isolated from 30-month-old rats was 65% less than that observed for hepatocytes from 6-month-old rats. In contrast to total RNA synthesis, the rate of poly(A) + RNA synthesis for the 30-month-old rats was significantly less than the rate for 19-month-old rats.

摘要

对从6月龄到3月龄雌性Fischer F344大鼠分离出的各种核糖核酸（RNA）的合成情况进行了比较。通过将掺入RNA作为尿苷-5'-单磷酸的[3H]乳清酸的量除以尿苷-5'-三磷酸池的比活性，来测定新鲜制备的肝细胞的RNA合成速率。19月龄大鼠肝细胞的总RNA合成速率比12月龄大鼠肝细胞的合成速率低40%。在19月龄和30月龄之间，未观察到总RNA合成速率有显著差异。30月龄大鼠掺入多聚腺苷酸（poly(A)）+RNA中的[3H]乳清酸的百分比比从6月龄大鼠分离出的肝细胞中观察到的百分比约低50%。12月龄和30月龄大鼠掺入多聚腺苷酸（poly(A)）-RNA作为核糖体RNA（38S、18S和5S RNA）或转运RNA的[3H]乳清酸的百分比相似。从30月龄大鼠分离出的肝细胞的多聚腺苷酸（poly(A)）+RNA合成速率比从6月龄大鼠分离出的肝细胞中观察到的合成速率低65%。与总RNA合成相反，30月龄大鼠的多聚腺苷酸（poly(A)）+RNA合成速率显著低于19月龄大鼠的合成速率。