Guldner N W, Klapproth P, Grossherr M, Stephan M, Rumpel E, Noel R, Sievers H H
Clinic of Cardiac Surgery, Medical University of Lübeck, Germany.
Circulation. 2000 May 9;101(18):2213-9. doi: 10.1161/01.cir.101.18.2213.
The profound loss of power that occurs in skeletal muscle after electrical conditioning has been the major limiting factor in its clinical application. This study investigates a 3-fold approach for chronic conditioning of skeletal muscle ventricles (SMVs) combining electrical transformation, dynamic training against systemic load, and pharmacological support with clenbuterol.
In 10 adult male goats, SMVs were constructed from latissimus dorsi muscle wrapped around an intrathoracic training device with windkessel characteristics. SMVs were stimulated electrically and trained dynamically by shifting volume against systemic load. Group 1 goats were controls (n=5), and group 2 goats (n=5) were supported with clenbuterol (150 microg 3 times a week). SMV dynamics were recorded weekly over 5 to 8 months: peak pressure (P(max)), stroke volume (SV), volume displacement per minute (VD), stroke work per day (SW/d), and maximum rates of pressure generation, +dP/dt(max), and decay, -dP/dt(max). In group 1, after 149.5+/-2.7 days (n=4), data were P(max)=70.8+/-4.7 mm Hg, SV=3.2+/-1.2 mL, VD=62.3+/-21.1 mL/min, SW/d=0.8+/-0.4 kJ, +dP/dt(max)=64+/-13 mm Hg/s, and -dP/dt(max)=156+/-32 mm Hg/s. These parameters were significantly improved (P<0.007) in the clenbuterol-treated group 2 after 151+/-2.7 days: P(max)=176.2+/-43.8 mm Hg, SV=23.3+/-6.1 mL, VD=568.2+/-186.1 mL/min, SW/d=9.1+/-2.2 kJ, +dP/dt(max)=1134+/-267 mm Hg/s, and -dP/dt(max)=1028+/-92 mm Hg/s. In 2 SMVs of group 2, VD increased to 1090 and 1235 mL/min after 202 and 246 days of training, respectively. At termination, myosin heavy chains were totally transformed into myosin heavy chain-1 in all SMVs.
This clenbuterol-supported dynamic training provides powerful SMVs that may have important clinical implications for the treatment of end-stage heart failure by muscular blood pumps.
电刺激调节后骨骼肌出现的显著力量丧失一直是其临床应用的主要限制因素。本研究探讨了一种对骨骼肌心室（SMV）进行长期调节的三重方法，该方法结合了电转化、针对全身负荷的动态训练以及使用克仑特罗的药理学支持。
在10只成年雄性山羊中，用包裹在具有风箱特性的胸腔内训练装置周围的背阔肌构建SMV。通过改变对抗全身负荷的容积对SMV进行电刺激和动态训练。第1组山羊为对照组（n = 5），第2组山羊（n = 5）给予克仑特罗（每周3次，每次150微克）支持。在5至8个月内每周记录SMV动力学：峰值压力（P(max)）、每搏输出量（SV）、每分钟容积位移（VD）、每天每搏功（SW/d）以及压力产生的最大速率、+dP/dt(max)和压力衰减速率、-dP/dt(max)。在第1组中，149.5±2.7天（n = 4）后的数据为：P(max)=70.8±4.7毫米汞柱，SV = 3.2±1.2毫升，VD = 62.3±21.1毫升/分钟，SW/d = 0.8±0.4千焦，+dP/dt(max)=64±13毫米汞柱/秒，-dP/dt(max)=156±32毫米汞柱/秒。在第2组接受克仑特罗治疗的山羊中，151±2.7天后这些参数有显著改善（P<0.007）：P(max)=176.2±43.8毫米汞柱，SV = 23.3±6.1毫升，VD = 568.2±186.1毫升/分钟，SW/d = 9.1±2.2千焦，+dP/dt(max)=1134±267毫米汞柱/秒，-dP/dt(max)=1028±92毫米汞柱/秒。在第2组的2个SMV中，训练202天和246天后，VD分别增加到1090和1235毫升/分钟。在实验结束时，所有SMV中的肌球蛋白重链完全转化为肌球蛋白重链-1。
这种使用克仑特罗支持的动态训练可提供强大的SMV，这对于通过肌肉血泵治疗终末期心力衰竭可能具有重要的临床意义。
