Lee J C, Downing S E
Am J Physiol. 1982 Feb;242(2):H191-6. doi: 10.1152/ajpheart.1982.242.2.H191.
Catecholamine cardiomyopathy (CM) was produced in rabbits by a 90-min infusion of norepinephrine (NE, 2 micrograms . kg-1 . min-1). Left ventricular (LV) contractility and pump function (VF) were examined 2 days later and compared with control animals. The effects of hypercapnia [CO2 tension (PCO2) greater than 70 mmHg] and inotropic responsiveness to NE were also determined. VF was assessed by means of left ventricular function curves obtained with constant aortic pressure and heart rate and quantified by determining stroke volume at left ventricular end-diastolic pressure of 10 cmH2O (SV10). Mean SV10 was 1.16 +/- 0.06 ml in controls but averaged only 0.93 +/- 0.05 in CM (P less than 0.02). Hypercapnia caused significantly greater depression of VF in CM than in controls. NE dose-response curves demonstrated increases in both LV dP/dtmax and SV10 in each group. The percent increase in LV dP/dtmax was markedly attenuated n CM, but the increments in SV10 did not differ. The mean histological score in the CM animals was 1.6 +/- 0.1, indicating extensive myofiber injury. No histological abnormalities were observed in the controls. Thus functional defects correlated with the presence of histopathological changes. In addition, a dissociation of velocity (dP/dtmax) and force (SV10) responsiveness to inotropic stimulation was identified in the CM group.
通过90分钟输注去甲肾上腺素（NE，2微克·千克⁻¹·分钟⁻¹）在兔身上诱发儿茶酚胺心肌病（CM）。2天后检测左心室（LV）收缩力和泵功能（VF），并与对照动物进行比较。还测定了高碳酸血症[二氧化碳分压（PCO₂）大于70 mmHg]的影响以及对NE的变力反应性。通过在恒定主动脉压力和心率下获得的左心室功能曲线评估VF，并通过测定左心室舒张末期压力为10 cmH₂O时的每搏输出量（SV10）进行量化。对照组的平均SV10为1.16±0.06 ml，但CM组平均仅为0.93±0.05（P<0.02）。与对照组相比，高碳酸血症导致CM组的VF明显降低。NE剂量反应曲线显示每组的左心室dP/dtmax和SV10均增加。CM组左心室dP/dtmax的增加百分比明显减弱，但SV10的增加无差异。CM组动物的平均组织学评分为1.6±0.1，表明存在广泛的肌纤维损伤。对照组未观察到组织学异常。因此，功能缺陷与组织病理学变化的存在相关。此外，在CM组中发现了对变力刺激的速度（dP/dtmax）和力量（SV10）反应性的分离。
