Trifunovic B, Norton G R, Duffield M J, Avraam P, Woodiwiss A J
Department of Physiology, University of the Witwatersrand Medical School, Johannesburg, South Africa.
Am J Physiol. 1995 Mar;268(3 Pt 2):H1096-105. doi: 10.1152/ajpheart.1995.268.3.H1096.
The effect of chronic administration of an androgenic steroid on left ventricular (LV) compliance and contractility was studied in rats. Rats received a biweekly intramuscular injection of nandrolone decanoate (5 mg/kg; steroid group) or the vehicle (control group) for 3 mo. Cardiac performance was measured in anesthetized open-chest ventilated rats. LV compliance was determined from the slope of the LV end-diastolic pressure (LVEDP) vs. LV end-diastolic (LVED) strain relation measured in the long and short axes of the LV. LV regional myocardial compliance was determined from the slope of the LVED stress vs. LVED strain relation (myocardial elastic stiffness constant). Cardiac contractility was determined from the slope of the LV end-systolic (LVES) pressure vs. LVES strain relation. Systolic performance was also assessed from the slope of the pressure-length area (PL area) or stroke work vs. LVED strain and LVEDP relations. Nandrolone decanoate decreased body weight, heart weight, and plasma testosterone concentrations but increased the heart weight-to-body weight ratio. Nandrolone decanoate decreased LV compliance (slope of LVEDP vs. LVED strain relation in long and short axes; steroid vs. control, P < 0.01). This occurred as a result of an increased regional myocardial stiffness (myocardial elastic stiffness constant; steroid vs. control, P < 0.01), which resulted in a reduced cardiac systolic performance (PL area vs. LVEDP, slope of steroid vs. control group, P < 0.005). Diastolic geometry (LV wall thickness-to-radius ratio) and cardiac contractility were unchanged with steroid administration. In conclusion, chronic administration of the androgenic steroid nandrolone decanoate decreases LV myocardial compliance and thus overall cardiac performance without altering contractility in rats.
研究了长期给予雄激素类固醇对大鼠左心室（LV）顺应性和收缩性的影响。大鼠每两周接受一次癸酸诺龙（5 mg/kg；类固醇组）或赋形剂（对照组）的肌肉注射，持续3个月。在麻醉的开胸通气大鼠中测量心脏功能。LV顺应性通过测量LV舒张末期压力（LVEDP）与LV舒张末期（LVED）应变关系在LV长轴和短轴上的斜率来确定。LV局部心肌顺应性通过LVED应力与LVED应变关系（心肌弹性硬度常数）的斜率来确定。心脏收缩性通过LV收缩末期（LVES）压力与LVES应变关系的斜率来确定。还通过压力-长度面积（PL面积）或每搏功与LVED应变和LVEDP关系的斜率来评估收缩功能。癸酸诺龙降低了体重、心脏重量和血浆睾酮浓度，但增加了心脏重量与体重的比值。癸酸诺龙降低了LV顺应性（LVEDP与LVED应变关系在长轴和短轴上的斜率；类固醇组与对照组，P<0.01）。这是由于局部心肌硬度增加（心肌弹性硬度常数；类固醇组与对照组，P<0.01）导致的，进而导致心脏收缩功能降低（PL面积与LVEDP，类固醇组与对照组斜率，P<0.005）。给予类固醇后，舒张期几何形状（LV壁厚与半径比值）和心脏收缩性未改变。总之，长期给予雄激素类固醇癸酸诺龙可降低大鼠LV心肌顺应性，从而降低整体心脏功能，而不改变收缩性。
