Barsotti A, Di Napoli P, Dini F L, Soccio M, Di Iorio P, Gallina S, Di Muzio M, Modesti A
Department of Cardiology and Cardiac Surgery, University of Chieti, Italy.
J Med. 1998;29(3-4):137-58.
An acute increase of myocardial interstitial fluid may affect ventricular function. In the present study we evaluated the effects of acute changes of myocardial tissue fluid on cardiac function and ultrastructural morphometry. Isolated rat hearts were perfused for 100 min in the working heart mode. Hearts were distributed into 5 groups: controls [perfused with Krebs-Henseleit (KH) isotonic buffer to rat plasma, KH, 287 mOsm], moderate hyposmotic perfusion (75% Hyposm: perfusion with 75% diluted KH, 216 mOsm), highly hyposmotic perfusion (60% Hyposm: perfusion with 60% diluted KH, 170 mOsm), afterload increase (Pre-over: isotonic perfused hearts subjected to an increase of afterload from 72 to 145 cm H2O) and ion dilution (Ion-dil: hearts perfused with a 60% KH with 115 mM sucrose, isotonic, 287 mOsm). We evaluated functional changes, markers of cellular necrosis or damage (CPK, LDH and purine release in coronary effluent), heart weight changes (weight gain and ww/dw ratio) and ultrastructural morphometry (analysis of cell damage, interstitial area, and mitochondrial alterations by a computerized image analysis system). The ww/dw ratio increased significantly only in 60% Hyposm (+140%, p < 0.001) and Pre-over (+63%, p < 0.001 vs control) groups. An impaired myocardial function in 60% Hyposm, Pre-over and Ion-dil groups was observed with cardiac failure at 50, 60 and 60 min, respectively. Enzyme release was significant higher in 60% Hyposm and Pre-over groups and was related to heart weight gain (r = 0.85, p < 0.001). Ultrastructural analysis confirmed a significant increase of interstitial space area (ISA) and mitochondrial damage in 60% Hyposm and Pre-over groups (p < 0.001); a significant (p < 0.05) increase was observed in the Ion-dil group; in 75% Hyposm group, a significant increase of mitochondrial damage was detected (p < 0.05). In brief, a higher functional and morphological deterioration was observed in hearts in which a more evident interstitial edema was detected (60% Hyposm and Pre-over groups). We conclude that, in the experimental condition, an acute increase of myocardial interstitial tissue fluid directly compromises left ventricular function and contributes to the ultrastructural damage to the myocardium.
心肌间质液的急性增加可能会影响心室功能。在本研究中，我们评估了心肌组织液急性变化对心脏功能和超微结构形态测量的影响。将离体大鼠心脏在工作心脏模式下灌注100分钟。心脏被分为5组：对照组[用与大鼠血浆等渗的克雷布斯 - 亨塞尔特（KH）缓冲液灌注，KH，287 mOsm]、中度低渗灌注（75%低渗：用75%稀释的KH灌注，216 mOsm）、高度低渗灌注（60%低渗：用60%稀释的KH灌注，170 mOsm）、后负荷增加组（前负荷增加：等渗灌注的心脏后负荷从72增加到145 cm H₂O）和离子稀释组（离子稀释：用含115 mM蔗糖的60% KH灌注心脏，等渗，287 mOsm）。我们评估了功能变化、细胞坏死或损伤标志物（冠状动脉流出液中的肌酸磷酸激酶、乳酸脱氢酶和嘌呤释放）、心脏重量变化（重量增加和湿重/干重比）以及超微结构形态测量（通过计算机图像分析系统分析细胞损伤、间质面积和线粒体改变）。湿重/干重比仅在60%低渗组（增加140%，p < 0.001）和前负荷增加组（增加63%，与对照组相比p < 0.001）显著增加。在60%低渗组、前负荷增加组和离子稀释组中观察到心肌功能受损，分别在50、60和60分钟时出现心力衰竭。60%低渗组和前负荷增加组的酶释放显著更高，且与心脏重量增加相关（r = 0.85，p < 0.001）。超微结构分析证实，60%低渗组和前负荷增加组的间质空间面积（ISA）和线粒体损伤显著增加（p < 0.001）；离子稀释组有显著（p < 0.05）增加；在75%低渗组中，检测到线粒体损伤显著增加（p < 0.05）。简而言之，在检测到更明显间质水肿的心（60%低渗组和前负荷增加组）中观察到更高程度的功能和形态恶化。我们得出结论，在实验条件下，心肌间质组织液的急性增加直接损害左心室功能，并导致心肌超微结构损伤。
