Libonati Joseph R
Department of Kinesiology, Temple University, Philadelphia, PA 19003, USA.
Med Sci Sports Exerc. 2003 Sep;35(9):1471-6. doi: 10.1249/01.MSS.0000084420.77802.DA.
The purpose of this study was to determine the effects of exercise training on LV geometry and LV diastolic function in a rat model of MI.
One month after MI induced by ligation of the left anterior descending artery (N = 45) or sham operation (N = 26), rats were randomized to either a sedentary or exercise group. Exercise consisted of treadmill running at 24 m.min-1, 1 h.d-1, 5 d.wk-1, for 3 wk. Passive LV pressure volume relationships were established with an isolated, red-cell-perfused Langendorff preparation. Infarct size was determined histologically and categorized as small (<30% of LV) or large (> or =30% of LV).
LV end-diastolic pressure-volume relationships were shifted rightward with increasing infarct size (P < 0.05). Exercise training further shifted the LV end-diastolic pressure-volume relationships rightward in sham, small MI and large MI (P < 0.05). Peak LV developed pressure was comparable in sedentary and exercised-trained hearts in sham, small MI, and large MI. LV diameter and septal wall thickness were greatest in large MI (P < 0.05). Exercise-trained hearts showed a tendency for a greater LV diameter and septal wall thickness in sham, small MI, and large MI. Scar thinning was most notable in large MI (P < 0.05).
Moderate-intensity treadmill running induces myocardial remodeling and a rightward shift in the LV end-diastolic pressure-volume relationship after MI, an adaptation similar to what is observed with exercise training in sham hearts without MI.
本研究旨在确定运动训练对心肌梗死大鼠模型左心室几何形态和左心室舒张功能的影响。
在通过结扎左前降支诱导心肌梗死后1个月（N = 45）或假手术（N = 26），将大鼠随机分为久坐组或运动组。运动包括在跑步机上以24米/分钟的速度跑步，每天1小时，每周5天，持续3周。使用离体的、红细胞灌注的Langendorff标本建立被动左心室压力-容积关系。通过组织学方法确定梗死面积，并将其分为小梗死（<左心室的30%）或大梗死（≥左心室的30%）。
随着梗死面积增加，左心室舒张末期压力-容积关系向右移位（P < 0.05）。运动训练使假手术组、小面积心肌梗死组和大面积心肌梗死组的左心室舒张末期压力-容积关系进一步向右移位（P < 0.05）。在假手术组、小面积心肌梗死组和大面积心肌梗死组中，久坐组和运动训练组心脏的左心室最大压力发展值相当。大面积心肌梗死组的左心室直径和室间隔厚度最大（P < 0.05）。在假手术组、小面积心肌梗死组和大面积心肌梗死组中，运动训练的心脏显示出左心室直径和室间隔厚度增加的趋势。大面积心肌梗死组的瘢痕变薄最为明显（P < 0.05）。
中等强度的跑步机跑步可诱导心肌梗死后心肌重塑和左心室舒张末期压力-容积关系向右移位，这一适应性变化类似于在无心肌梗死的假手术心脏中运动训练所观察到的情况。
