Accelerated ribosome formation and growth in neonatal pig hearts.
Accelerated ribosome formation and growth in neonatal pig hearts.
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加速新生猪心脏中核糖体的形成和生长。
DOI：
10.1152/ajpcell.1990.258.1.c86
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Morgan,HE
中科院分区：
文献类型：
--
作者：
Camacho,JA;Peterson,CJ;White,GJ;Morgan,HE
新生猪心脏左心室自由壁（LVFW）的快速生长（5 mg干心/h）伴随着右心室自由壁（RVFW）的缺乏生长，代表了一种独特的自然心脏扩大模型，不受病理生理影响。3 d时，LVFW比4 h时大71%。在用含有葡萄糖、乳酸、胰岛素的碳酸氢盐缓冲液和主动脉压为60 mmHg时的血浆氨基酸浓度灌注离体猪心脏时，测量蛋白质合成率。在18 h龄猪的心脏中，RVFW和LVFW的蛋白质合成率相同，但在2日龄猪的心脏中，LVFW的蛋白质合成率比RVFW高52%。在生命的前3天，LVFW的RNA含量（mg/g）比RVFW快3.4倍。当RNA含量在每个心脏部分表达时，增加了7.9倍。由于大约85%的总RNA是rRNA，这些值表明LVFW中核糖体的形成比RVFW要快得多。48 h大的猪体外心脏核糖体的形成率，LVFW比RVFW高39%，18 h时，LVFW的核糖体形成速度比RVFW快40%。这些发现表明新的核糖体的形成先于总心脏蛋白的加速合成。这些发现表明，与不生长的RVFW相比，LVFW的快速生长与核糖体形成速度快67%和蛋白质合成速度快32%相关。
Rapid growth (5 mg dry heart/h) of the left ventricular free wall (LVFW) in the newborn pig heart accompanied by lack of growth of the right ventricular free wall (RVFW) represents a unique natural model of cardiac enlargement that is free of pathophysiological influences. By 3 days of life, LVFW was 71% larger than at 4 h of age. Rates of protein synthesis were measured during perfusion of isolated pig hearts with bicarbonate buffer containing glucose, lactate, insulin, and plasma concentrations of amino acids of an aortic pressure of 60 mmHg. In hearts from pigs that were 18 h of age, rates of protein synthesis were the same in RVFW and LVFW, but in 2-day-old pigs the rate was 52% greater in LVFW than RVFW. During the first 3 days of life, RNA content (mg/g) increased 3.4-fold faster in LVFW than RVFW. When RNA content was expressed per total heart portion, the increase was 7.9-fold greater. Because approximately 85% of total RNA is rRNA, these values indicated much more rapid formation of ribosomes in the LVFW than RVFW. When ribosome formation was measured in vitro in hearts from 48-h-old pigs, rates of formation were 39% greater in LVFW than RVFW, and at 18 h of age, ribosome formation was 40% faster in LVFW than RVFW. These findings indicated that formation of new ribosome preceded accelerated synthesis of total heart proteins. These findings indicated that rapid growth of LVFW compared with no growth of RVFW was associated with a 67% faster rate of ribosome formation and a 32% greater rate of protein synthesis.