Morita K, Koyanagi K, Sakamoto Y, Wakabayashi K, Tanaka K, Horikoshi S, Matsui M, Arai T
Department of Cardiac Surgery, Jikey University School of Medicine, Tokyo, Japan.
Nihon Kyobu Geka Gakkai Zasshi. 1991 Mar;39(3):276-83.
We have studied contractile property and fatigue rates of skeletal muscle ventricle (SMV) constructed using the latissimus dorsi muscles of 11 dogs. The role of early interruption of collateral blood supply in the prevention of muscle ischemia and SMV fatigue was evaluated. Systolic function of SMV was measured in a hydraulic test system; afterload was set at 70 mmHg and preload 15 or 25 mmHg. Control SMV (GI: N = 7), which was fashioned immediately after interruption of collateral blood supply, generated an initial SMV pressure of 222 +/- 50 mmHg and stroke volume of 15 +/- 7 ml/beat with muscle stimulation at a burst-frequency of 50 Hz, but could sustain flow for only 3.5 +/- 0.8 minutes. SMV subjected to a vascular delay (Group II: N = 4) demonstrated improvement of fatigue rates; duration of flow 32.4 +/- 14.0 and sufficient contractile property (initial SMV pressure 182 +/- 17 mmHg, stroke volume 1- +/- 2 ml/beat). Thermography surface temperature mapping revealed remarkable improvement of blood distribution in GII muscles. Flow rates of thoracodorsal artery were significantly greater in GII muscles compared to those in GI muscles (15.0 +/- 3.7 ml/min/LD 100 g, 10.1 +/- 3.1 ml/min/LD 100 g, p less than 0.05, respectively). Despite significant improvement of functional durability in GII muscles, the ratio of oxygen consumption to lactate output was not different between 2 groups. These results suggest that early interruption of collateral blood supply can minimize muscle ischemia, resulting in diminishing fatigue of latissimus dorsi muscles without changes in skeletal muscle metabolism.
我们研究了用11只狗的背阔肌构建的骨骼肌心室（SMV）的收缩特性和疲劳率。评估了早期中断侧支血供在预防肌肉缺血和SMV疲劳中的作用。在液压测试系统中测量SMV的收缩功能；后负荷设定为70 mmHg，前负荷设定为15或25 mmHg。对照组SMV（GI组：N = 7）在侧支血供中断后立即构建，在50 Hz的爆发频率下进行肌肉刺激时，产生的初始SMV压力为222±50 mmHg，每搏输出量为15±7 ml/次，但仅能维持血流3.5±0.8分钟。经历血管延迟的SMV（II组：N = 4）显示疲劳率有所改善；血流持续时间为32.4±14.0分钟，且具有足够的收缩特性（初始SMV压力182±17 mmHg，每搏输出量1±2 ml/次）。热成像表面温度图谱显示II组肌肉的血液分布有显著改善。与GI组肌肉相比，II组肌肉的胸背动脉血流速率显著更高（分别为15.0±3.7 ml/min/LD 100 g和10.1±3.1 ml/min/LD 100 g，p < 0.05）。尽管II组肌肉的功能耐久性有显著改善，但两组之间的氧耗与乳酸输出比值并无差异。这些结果表明，早期中断侧支血供可使肌肉缺血最小化，从而减少背阔肌的疲劳，而骨骼肌代谢无变化。
