Mulieri L A, Hasenfuss G, Ittleman F, Blanchard E M, Alpert N R
Department of Physiology and Biophysics, University of Vermont, College of Medicine, Burlington 05405.
Circ Res. 1989 Nov;65(5):1441-9. doi: 10.1161/01.res.65.5.1441.
To prevent dissection injury when cutting strip preparations from human left ventricular papillary muscle tissue, dissections were carried out with 2,3-butanedione monoxime (30 mM) added to Krebs-Ringer solution and followed by washout with normal solution. Eleven muscle strip preparations were dissected from left ventricular papillary muscle tissue of five patients undergoing mitral valve replacement surgery. The average muscle strip length was 6.8 +/- 1.4 mm, and cross-section area was 0.49 +/- 0.16 mm2. Peak twitch tension was 2.02 +/- 1.33 g/mm2 and ranged from 0.67 to 5.5 g/mm2 at an extracellular calcium concentration of 2.5 mM (21 degrees C, 0.16 Hz). In one muscle strip, which was stored in Krebs-Ringer plus 2,3-butanedione monoxime solution for 20 hours, peak twitch tension in normal Krebs-Ringer solution was 1.85 g/mm2. When temperature was increased from 21 degrees C, there was a continuous increase in peak twitch tension (by 38%) up to about 28 degrees C; then peak twitch tension decreased so that at 37 degrees C (n = 3) average peak twitch tension was lower than at 21 degrees C by 47%. The force-frequency relation exhibited a broad force plateau between 40 and 120 beats/min at 37 degrees C. The plateau was markedly narrowed at 30 degrees C and 24 degrees C. Thermopile heat measurements revealed appropriate waveform characteristics in high-resolution single-beat heat records indicating minimal surface cell damage. Thus, cardioplegia with 2,3-butanedione monoxime protects human left ventricular myocardium from dissection injury facilitating dissection and preservation of strip preparations with extraordinarily low cross-sectional areas and high peak twitch tensions. These preparations are suitable for myothermal and mechanical measurements.
为防止在从人左心室乳头肌组织切取肌条制剂时发生解剖损伤，在Krebs-Ringer溶液中添加2,3-丁二酮一肟（30 mM）进行解剖，然后用正常溶液冲洗。从5例接受二尖瓣置换手术患者的左心室乳头肌组织中切取了11条肌条制剂。肌条平均长度为6.8±1.4 mm，横截面积为0.49±0.16 mm²。在细胞外钙浓度为2.5 mM（21℃，0.16 Hz）时，峰值收缩张力为2.02±1.33 g/mm²，范围为0.67至5.5 g/mm²。在一条储存在含2,3-丁二酮一肟的Krebs-Ringer溶液中20小时的肌条中，正常Krebs-Ringer溶液中的峰值收缩张力为1.85 g/mm²。当温度从21℃升高时，峰值收缩张力持续增加（增加38%），直至约28℃；然后峰值收缩张力下降，因此在37℃（n = 3）时，平均峰值收缩张力比21℃时低47%。力-频率关系在37℃时40至120次/分钟之间呈现出较宽的力平台期。在30℃和24℃时，该平台期明显变窄。热电堆热测量显示，高分辨率单搏热记录具有合适的波形特征，表明表面细胞损伤最小。因此，用2,3-丁二酮一肟进行心脏停搏可保护人左心室心肌免受解剖损伤，便于切取具有极低横截面积和高峰值收缩张力的肌条制剂并进行保存。这些制剂适用于肌热和力学测量。
