Nakai N, Sato Y, Oshida Y, Yoshimura A, Fujitsuka N, Sugiyama S, Shimomura Y
Research Center of Health, Physical Fitness and Sports, Nagoya University, Japan.
Life Sci. 1997;60(25):2309-14. doi: 10.1016/s0024-3205(97)00286-5.
Effects of aging on the activities of heart pyruvate dehydrogenase complex and pyruvate dehydrogenase kinase were examined using 7, 35 and 60 wk old rats. Aging did not affect the total activity of pyruvate dehydrogenase complex but decreased the activity state (percentage of active form) of the complex in rats under the fed condition (52%, 36% and 26% for 7, 35 and 60 wk old rats, respectively). This decrease in the complex activity with aging was suggested to be associated with an age-related decrease in the blood glucose disposal. Starvation for 24 h decreased the activity state to less than 3% in all of the age groups. The activity of pyruvate dehydrogenase kinase associated with the complex was not related to the alteration in the activity state of the complex; the kinase activity was slightly lower in 60 wk old rats than in the younger rats under the fed condition and activation of the kinase by starvation was greater in the younger rats. The mechanism for the decrease in activity of pyruvate dehydrogenase complex was discussed on the basis of glucose and fatty acid utilization of heart muscle cells.
使用7周龄、35周龄和60周龄的大鼠，研究了衰老对心脏丙酮酸脱氢酶复合体和丙酮酸脱氢酶激酶活性的影响。衰老并未影响丙酮酸脱氢酶复合体的总活性，但在喂食条件下，大鼠体内该复合体的活性状态（活性形式的百分比）降低（7周龄、35周龄和60周龄大鼠分别为52%、36%和26%）。随着衰老，该复合体活性的降低被认为与血糖处置的年龄相关下降有关。饥饿24小时后，所有年龄组的活性状态均降至3%以下。与该复合体相关的丙酮酸脱氢酶激酶活性与复合体活性状态的改变无关；在喂食条件下，60周龄大鼠的激酶活性略低于年轻大鼠，饥饿对年轻大鼠激酶的激活作用更大。基于心肌细胞对葡萄糖和脂肪酸的利用，讨论了丙酮酸脱氢酶复合体活性降低的机制。
