Fields A L, Cheema-Dhadli S, Wolman S L, Halperin M L
Cancer. 1982 Nov 15;50(10):2183-8. doi: 10.1002/1097-0142(19821115)50:10<2183::aid-cncr2820501034>3.0.co;2-7.
In the analysis of weight loss in cancer patients, consideration must be given to decreased caloric intake, increased caloric expenditure and abnormal losses of calories. When these factors do not adequately explain the degree of weight loss, this may be due to a specific loss of lean body mass, as the caloric density of muscle is much less than that of fat. The key enzyme for the protection of lean body mass in hypocaloric states is pyruvate dehydrogenase (PDH). During fasting, fast oxidation in host tissues leads to inactivation of PDH, preventing irreversible loss of pyruvate precursors which would have to be replaced by protein breakdown. A tumor in which PDH activity remains high in the fasting state would cause loss of lean body mass in the host. This report suggests that this phenomenon may be important in certain patients with cancer cachexia.
在分析癌症患者体重减轻的情况时，必须考虑热量摄入减少、热量消耗增加以及热量异常流失。当这些因素不足以解释体重减轻的程度时，这可能是由于瘦体重的特定损失，因为肌肉的热量密度远低于脂肪。在低热量状态下保护瘦体重的关键酶是丙酮酸脱氢酶（PDH）。在禁食期间，宿主组织中的快速氧化导致PDH失活，防止丙酮酸前体的不可逆损失，否则这些前体将不得不通过蛋白质分解来替代。在禁食状态下PDH活性仍然很高的肿瘤会导致宿主瘦体重的损失。本报告表明，这种现象在某些癌症恶病质患者中可能很重要。
