Age-related alterations in cardiac protein turnover.
Age-related alterations in cardiac protein turnover.
复制标题
心脏蛋白质周转率与年龄相关的变化。
DOI：
10.1016/0022-2828(81)90329-1
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发表时间：
1981
影响因子：
5
通讯作者：
Wildenthal,K
中科院分区：
文献类型：
--
作者：
Crie,JS;Millward,DJ;Bates,PC;Griffin,EE;Wildenthal,K
在体外和体内研究了衰老对大鼠心脏蛋白周转的影响。在改良的Langendorff灌注仪上体外灌注含有环己亚胺的缓冲液以抑制蛋白质合成，并测量苯丙氨酸释放到灌注液中的速率作为蛋白质降解的指标。1 ~ 2月龄大鼠心脏苯丙氨酸释放量为0.22±0.013 nmol/mg wet wt/h， 10 ~ 14月龄大鼠心脏苯丙氨酸释放量为0.16±0.011 nmol/mg/h （P< 0.005）。这表明老年大鼠灌注心脏中心脏蛋白降解率降低了27%。当灌注液中存在胰岛素时，这些年龄组动物心脏蛋白降解率的差异相似（老年动物降低21%，P< 0.01）。用[14 C]酪氨酸持续输注技术测定体内蛋白质周转。心脏蛋白降解分数率由11 ~ 2月龄时的14.8±1.06%/d降至12月龄时的10.8±0.91%/d （P< 0.05）。老龄大鼠蛋白质合成速率也较慢，由1 ~ 2月龄时的19.6±1.63%/d降至12月龄时的10.8±0.91%/d （P< 0.005）。老年（24月龄）蒙面大鼠心脏蛋白合成和降解分数率进一步降低至6.7±0.29%/天，而同品系12月龄大鼠为12.4±0.61%/天（P< 0.005）。因此，我们认为心脏蛋白的降解和合成随着年龄的增长而减少。
The influence of aging on cardiac protein turnover in rats was studied in vitro and in vivo. Hearts were perfused in vitro on a modified Langendorff perfusion apparatus with buffer containing cycloheximide to inhibit protein synthesis, and the rate of phenylalanine release into the perfusate was measured as an index of protein degradation. Phenylalanine release from hearts of 1-to 2 1 2-month-old rats was 0.22±0.013 nmol/mg wet wt/h compared to 0.16±0.011 nmol/mg/h from hearts of 10-to 14-month-old animals (P< 0.005). This represents a 27% decrease in the rate of cardiac protein degradation in perfused hearts of older rats. When insulin was present in the perfusate the difference in cardiac protein degradation rates between animals in these age groups was similar (21% decrease in older animals, P< 0.01). Protein turnover in vivo was measured by the constant infusion technique using [14 C] tyrosine. The fractional rate of cardiac protein degradation decreased from 14.8±1.06%/day at 1 1 2 months of age to 10.8±0.91%/day at 12 months of age (P< 0.05). The rate of protein synthesis was also slower in the older rats, decreasing from 19.6±1.63%/day at 1 1 2 months to 10.8±0.91%/day at 12 months (P< 0.005). In senile (24-month-old) hooded rats the fractional rates of cardiac protein synthesis and degradation were further reduced to 6.7±0.29%/day compared to 12.4±0.61%/day for 12-month-old rats of the same strain (P< 0.005). Thus, we conclude that cardiac protein degradation and synthesis decrease with aging.