Cicogna A C, Robinson K G, Conrad C H, Squire R, Okoshi M P, Bing O H
Faculdade de Medicina de Botucatu-UNESP.
Arq Bras Cardiol. 1997 Dec;69(6):381-4. doi: 10.1590/s0066-782x1997001200003.
To investigate the participation of contractile state and relaxation in cardiac muscle dysfunction during the transition from stable hypertrophy to cardiac decompensation in aging spontaneously hypertensive rats (SHR).
Isolated left ventricular papillary muscle function was studied in SHR with heart failure (SHR-F), in age-matched SHR without evidence of heart failure (SHR-NF), and in nonhypertensive controls Wistar-Kyoto rats (WKY). Muscles were analysed in isometric and isotonic contractions in Krebs-Henseleit solution with calcium concentration of 1.25 mM at 28 degrees C.
Papillary muscles from SHR-F and SHR-NF demonstrated decreased active tension development and shortening velocity relative to normotensive WKY (p < 0.05). SHR-F and SHR-NF did not differ. Compared with SHR-NF and WKY, muscle passive stiffness was increased in the failing SHR (p < 0.05 versus WKY and SHR-NF). This parameter did not differ between SHR-NF and WKY (p > 0.05).
These data suggest that the progression from stable hypertrophy to heart failure is associated with changes in the passive stiffness and is not related to depression of myocardial contractile function.
研究衰老自发性高血压大鼠（SHR）从稳定肥大转变为心脏失代偿过程中，收缩状态和舒张功能在心肌功能障碍中的作用。
对心力衰竭的SHR（SHR-F）、年龄匹配且无心力衰竭证据的SHR（SHR-NF）以及非高血压对照Wistar-Kyoto大鼠（WKY）的离体左心室乳头肌功能进行研究。在28℃下，于钙浓度为1.25 mM的Krebs-Henseleit溶液中对肌肉进行等长和等张收缩分析。
与正常血压的WKY相比，SHR-F和SHR-NF的乳头肌表现出主动张力发展和缩短速度降低（p < 0.05）。SHR-F和SHR-NF之间无差异。与SHR-NF和WKY相比，衰竭的SHR肌肉被动僵硬度增加（与WKY和SHR-NF相比，p < 0.05）。该参数在SHR-NF和WKY之间无差异（p > 0.05）。
这些数据表明，从稳定肥大到心力衰竭的进展与被动僵硬度的变化有关，而与心肌收缩功能的降低无关。
