Sjöström M, Wretling M L, Karlberg I, Edén E, Lundholm K
J Surg Res. 1987 Mar;42(3):304-13. doi: 10.1016/0022-4804(87)90148-x.
Morphometric data on left ventricular papillary muscle structures have been determined in tumor-induced malnutrition and related to the maximum activities of key enzymes for energy production in the whole myocardium. Adult, nongrowing mice with a syngeneic sarcoma were used to represent a condition of cancer associated host tissue wasting. Hearts from mice 11 days after tumor implantation showed atrophy and a significantly reduced amount of myofibrillar, soluble, and collagen proteins than hearts from control animals. The cross-sectional area of myocardial cells was 33% smaller in tumor-bearing mice (p less than 0.025), but the total number of capillaries and the residual interstitial volume were similar in the two groups. The total number of subcellular structures per cell, such as mitochondria, myofibrils, and myosin filaments per myofiber, were significantly lower in the tumor-bearing animals (p less than 0.025). Conversely, the proportion of myofibrils was higher (p less than 0.05) in tumor-bearing animals while the proportion of mitochondria was lower. Maximum activities (Vmax) of selected regulatory key enzymes for energy production (glycogenolytic, glycolytic, and mitochondrial) were not significantly altered in hearts from tumor-bearing mice. The results support the conclusion that myocardial functional capacity is better preserved than overall structural components would imply in tumor-host associated malnutrition, which is probably secondary to deprived food intake. Teleologically, this may be a means by which functional deterioration of the heart is minimized during the induction of malnutrition.
已测定肿瘤诱导的营养不良小鼠左心室乳头肌结构的形态计量学数据，并将其与整个心肌中能量产生关键酶的最大活性相关联。使用患有同基因肉瘤的成年、非生长小鼠来代表癌症相关的宿主组织消瘦情况。肿瘤植入后11天的小鼠心脏显示出萎缩，与对照动物的心脏相比，肌原纤维、可溶性和胶原蛋白的含量显著降低。荷瘤小鼠心肌细胞的横截面积小33%（p<0.025），但两组的毛细血管总数和残余间质体积相似。荷瘤动物每个细胞的亚细胞结构总数，如每个肌纤维的线粒体、肌原纤维和肌球蛋白丝，显著更低（p<0.025）。相反，荷瘤动物中肌原纤维的比例更高（p<0.05），而线粒体的比例更低。荷瘤小鼠心脏中所选能量产生调节关键酶（糖原分解、糖酵解和线粒体酶）的最大活性（Vmax）没有显著改变。结果支持以下结论：在肿瘤宿主相关的营养不良中，心肌功能能力比整体结构成分所暗示的情况保存得更好，这可能继发于食物摄入不足。从目的论角度来看，这可能是一种在营养不良诱导期间将心脏功能恶化降至最低的方式。
