Mazzadi A, Gomez Llambi H, Basso N
Instituto de Investigaciones Cardiológicas, Facultad de Medicina, Universidad de Buenos Aires, Argentina.
Clin Exp Hypertens. 1998 Nov;20(8):867-84. doi: 10.3109/10641969809053252.
Previous experiments showed that enalapril (EN) treatment as well as enalaprilic acid, when added to the perfusion bath, diminish the inotropic response of the papillary muscles to isoproterenol (ISO). The main objective of this study was to evaluate, in normal rats, the effect of EN on basal contractility and inotropic response to ISO on the whole perfused ventricles (Langendorff preparation). Blood pressure (BP), increase in body weight (IBW), ventricular weight/body weight ratio (R) and concentration of ventricular proteins and DNA were also analyzed. Five groups were studied: EN10: 5 mg/kg/day, 10 days; EN21(L): 5mg/kg/day, 21 days; EN21(H): 15 mg/kg/day, 21 days. C10 and C21 were untreated controls. Cardiac contractility was evaluated by the maximal developed pressure, maximal rate of rise of pressure and maximal velocity of relaxation; no changes were found due to EN treatments either on basal conditions or on ISO stimulation. Significant differences (p<0.05 vs C21) were: lower BP and R in EN21(L) and EN21(H), slower IBW in EN21(H), decreased ventricular DNA in EN21(H). In conclusion, daily treatment for ten or twenty one days with enalapril does not change either basal cardiac contractile performance or inotropic response to ISO in the Langendorff preparation. Longterm treatment with EN seems to modify nuclear processes involved in cardiomyocite DNA content.
先前的实验表明，将依那普利（EN）以及依那普利酸添加到灌注浴中时，会减弱乳头肌对异丙肾上腺素（ISO）的变力反应。本研究的主要目的是评估在正常大鼠中，EN对整个灌注心室（Langendorff制备）的基础收缩力和对ISO的变力反应的影响。还分析了血压（BP）、体重增加（IBW）、心室重量/体重比（R）以及心室蛋白质和DNA的浓度。研究了五组：EN10：5mg/kg/天，共10天；EN21(L)：5mg/kg/天，共21天；EN21(H)：15mg/kg/天，共21天。C10和C21为未治疗的对照组。通过最大发展压力、最大压力上升速率和最大舒张速度评估心脏收缩力；在基础条件或ISO刺激下，未发现EN治疗导致任何变化。显著差异（与C21相比，p<0.05）为：EN21(L)和EN21(H)中的BP和R较低，EN21(H)中的IBW较慢，EN21(H)中的心室DNA减少。总之，在Langendorff制备中，用依那普利每日治疗10天或21天，既不会改变基础心脏收缩性能，也不会改变对ISO的变力反应。长期使用EN似乎会改变参与心肌细胞DNA含量的核过程。
