Piccinato C E, Santos A C, Roselino J E
Departamentos de Cirurgia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Brasil.
Braz J Med Biol Res. 1991;24(11):1125-8.
Skeletal muscle temperature and mitochondrial content of Ca2+ and Mg2+ were measured after 3 h of total or partial limb ischemia in male Wistar rats (250-350 g). The decreases in biceps muscle temperature, measured with a needle thermistor (4.4 +/- 0.26 degrees C, mean +/- SEM (17 rats) and 6.3 +/- 0.26 degrees C (31 rats) in partial ischemia (PI, aorta clamp) and total ischemia (TI, hind leg tourniquet), respectively) were consistent with the expected extent of blood flow reduction for the two ischemic conditions. Mitochondrial calcium levels increased after partial ischemia from 2.67 +/- 0.13 (46 rats) to 4.65 +/- 0.38 (12 rats) nmol/mg protein and increased to 7.87 +/- 0.68 (14 rats) after total ischemia (P less than 0.05). In contrast, mitochondrial magnesium decreased after partial ischemia from 10.14 +/- 0.35 to 8.22 +/- 0.28 (13 rats) but increased in the mitochondria of muscle submitted to total ischemia to 12.0 +/- 0.80 (14 rats; P less than 0.05). No changes were observed in the number of binding sites for safranine, which competes for calcium binding sites on the inner mitochondrial membrane (25.46 +/- 0.38 nmol/mg protein for sham (20 rats) and 25 +/- 0.68 (7 rats) for PI and 25 +/- 0.31 (5 rats) for TI). The data suggest that the greater resistance of rat muscle to total than to partial ischemia may be due at least in part to the increased mitochondrial Mg2+ content.
在雄性Wistar大鼠（250 - 350克）经历3小时的全肢或部分肢体缺血后，测量其骨骼肌温度以及线粒体中钙和镁的含量。用针型热敏电阻测量的肱二头肌温度下降情况（部分缺血（PI，主动脉夹闭）时为4.4±0.26℃，平均±标准误（17只大鼠）；全缺血（TI，后腿止血带）时为6.3±0.26℃（31只大鼠））与两种缺血情况下预期的血流减少程度一致。部分缺血后线粒体钙水平从2.67±0.13（46只大鼠）升高至4.65±0.38（12只大鼠）nmol/mg蛋白质，全缺血后升高至7.87±0.68（14只大鼠）（P<0.05）。相比之下，部分缺血后线粒体镁含量从10.14±0.35降至8.22±0.28（13只大鼠），但在经历全缺血的肌肉线粒体中升高至12.0±0.80（14只大鼠；P<0.05）。对于与线粒体内膜上钙结合位点竞争的番红染料结合位点数量，未观察到变化（假手术组（20只大鼠）为25.46±0.38 nmol/mg蛋白质，部分缺血组为25±0.68（7只大鼠），全缺血组为25±0.31（5只大鼠））。数据表明，大鼠肌肉对全缺血的耐受性高于部分缺血，这可能至少部分归因于线粒体镁含量的增加。
