Physiological hyperinsulinemia inhibits myocardial protein degradation in vivo in the canine heart.
Physiological hyperinsulinemia inhibits myocardial protein degradation in vivo in the canine heart.
复制标题
生理性高胰岛素血症抑制犬心脏体内的心肌蛋白降解。
DOI：
10.1161/01.res.71.2.393
复制
发表时间：
1992
影响因子：
20.1
通讯作者：
Barrett,EJ
中科院分区：
文献类型：
--
作者：
Young,LH;Dahl,DM;Rauner,D;Barrett,EJ
在16小时或36小时禁食后，在高胰岛素（2 mU/kg /分钟）正血糖钳夹期间（有或没有氨基酸替代或生理盐水输注期间）再次检测麻醉犬的心肌蛋白代谢。我们测量心肌苯丙氨酸平衡和蛋白质合成和降解的速率，使用提取静脉注射L-[环2,6- 3h]苯丙氨酸和稀释其在同位素稳定状态下在心脏的特定活性。禁食16小时（n = 19）和36小时（n = 10）后，心肌苯丙氨酸净释放量分别为-52 +/- 9 （p < 0.001）和-38 +/- 9 (p < 0.005) nmol/min。总体而言，禁食36小时的动物心肌蛋白降解的基础速率较低（81 +/- 13对121 +/- 12 nmol/min， p < 0.05）。禁食36小时的动物（n = 10）在胰岛素和葡萄糖输注期间，心肌苯丙氨酸平衡和蛋白质合成和降解率没有改变。在这些动物中，血浆氨基酸浓度下降了30-40%，包括支链氨基酸（p < 0.001）和必需氨基酸（p < 0.001）。（摘要删节250字）
Myocardial protein turnover in vivo was examined in anesthetized dogs following a 16- or 36-hour fast and again during a hyperinsulinemic (2 mU/kg per minute) euglycemic clamp with or without amino acid replacement or during saline infusion. We measured myocardial phenylalanine balance and rates of protein synthesis and degradation, using the extraction of intravenously infused L-[ring-2,6-3H]phenylalanine and the dilution of its specific activity across the heart at isotopic steady state. After both a 16-hour (n = 19) and 36-hour fast (n = 10), there was net myocardial release of phenylalanine indicated by the negative balances for phenylalanine of -52 +/- 9 (p less than 0.001) and -38 +/- 9 (p less than 0.005) nmol/min, respectively. Overall, the basal rate of myocardial protein degradation was lower in the 36-hour-fasted animals (81 +/- 13 versus 121 +/- 12 nmol/min, p less than 0.05). Myocardial phenylalanine balance and rates of protein synthesis and degradation did not change during insulin and glucose infusion in the 36-hour-fasted animals (n = 10). In these animals, there was a 30-40% decline in plasma amino acid concentrations, including branched chain (p less than 0.001) and essential amino acids (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)