Onset of blood lactate accumulation exercise capacity, skeletal muscle fibers and metabolism before and after coronary artery bypass grafting.
Onset of blood lactate accumulation exercise capacity, skeletal muscle fibers and metabolism before and after coronary artery bypass grafting.
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冠状动脉旁路移植术前后血乳酸积累的运动能力、骨骼肌纤维和代谢的开始。
DOI：
10.1016/s0002-9149(88)80023-7
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
J. Karlsson
中科院分区：
文献类型：
--
作者：
J. Karlsson
对患有劳力性心绞痛的男性患者进行了 2 至 7 个冠状动脉旁路移植术 (CABG) 术前 (n = 7)、1 周、1 和 6 个月 (n = 6) 的研究。测试组包括分级锻炼，直到出现难以忍受的腿部用力或胸痛，或两者兼而有之。血乳酸蓄积、心绞痛、腿部用力和呼吸困难的发作根据乳酸浓度 2 mmol × 1−1 或 Borg 主观强度量表的评级 2 进行插值。术前开始出现的血乳酸蓄积和症状限制运动能力分别达到 58 和 100 W。 6个月后，血乳酸积累的相应数字相同，而症状限制的运动能力增加了58%。休息和轻度运动时的血乳酸相同（血乳酸开始积累），但在症状限制的运动能力（血乳酸峰值浓度）下则增加一倍以上。肌纤维分型显示慢肌纤维比例较低（35%），6 个月后没有变化。快肌C亚型术前升高（7%），但术后消失，快肌A亚型百分比相应增加。主要的肌肉生化变化是糖原分解途径和乳酸脱氢酶系统，它们似乎以定量方式增加，但相对乳酸脱氢酶同工酶模式没有变化。症状限制运动能力的增加与糖原分解活性和血乳酸峰值（即“无氧能力”增加）的增加有关。病因解释是否是胸痛的缓解，即心理生理特征或肌肉中发生的生化变化，只能推测。
Male patients with effort angina were studied before (n = 7), 1 week, and 1 and 6 months (n = 6) after coronary artery bypass grafting (CABG) with 2 to 7 grafts. The test battery included graded exercise, which was performed until unbearable leg exertion or chest pain, or both, was present. Onsets of blood lactate accumulation, anginal pain, leg exertion and dyspnea were interpolated for either the lactate concentration 2 mmol × 1−1or the ratings 2 on the Borg subjective intensity scale. Onsets of blood lactate accumulation and symptom-limited exercise capacity before surgery amounted to 58 and 100 W, respectively. The corresponding figures 6 months later were the same for onset of blood lactate accumulation, whereas symptom-limited exercise capacity had increased by 58%. Blood lactate was the same at rest and mild exercise (≌ onset of blood lactate accumulation) but more than doubled at symptom-limited exercise capacity (peak blood lactate concentration). Muscle fiber typing showed a low figure for the slow twitch fiber proportion (35%), which was unchanged after 6 months. Fast twitch subtype C was elevated before (7%) but disappeared after surgery, and fast twitch subtype A percent increased correspondingly. The major muscle biochemical changes were in the glycogenolytic pathway and the lactate dehydrogenase enzyme system, which appeared to increase in a quantitative manner, but with an unchanged relative lactate dehydrogenase isozyme pattern.The increased symptom-limited exercise capacity was related to the increased glycogenolytic activity and peak blood lactate (i.e., increased “anaerobic power”). Whether the causative explanation was the relief from chest pain, i.e., a psychophysiologic feature or the biochemical changes that took place in the muscle could only be speculated on.