Gmeiner R, Knapp E, Schwingshackl H, Dienstl F
Recent Adv Stud Cardiac Struct Metab. 1975;7:405-12.
The purpose of the study was to evaluate the effects of nitroglycerin on the mechanical and metabolic performance of the mammalian heart without interference from peripheral vascular and neurohumoral influences. Isolated rat hearts were perfused with a buffer containing 1 mug of alcoholic nitroglycerin/ml or an equivalent amount of alcohol. Mechanical performance was analyzed during external and isovolumic work; all hearts were subjected to mild hypoxia. Heart rate was kept constant by pacing. At constant atrial filling pressures end diastolic pressures and calculated wall stiffness were not significantly different for controls and nitroglycerin. Afterload, as quantitated by mean aortic pressure, was the same for both groups. Peak-systolic left ventricular pressure and dp/dt max during ejection and isovolumic work were significantly reduced by hypoxia (p less than 0.001), but not changed by nitroglycerin. Cardiac output, mean systolic left ventricular pressure, work, oxygen consumption, and calculated efficiency were decreased by hypoxia (p less than 0.001); lactate production was enhanced by the hypoxic state (p less than 0.001). Nitroglycerin had no influence on these parameters in either state. It is concluded that at constant rate, preload and afterload nitroglycerin has no effect on the mechanical performance and energy formation by aerobic and anaerobic means in the fully oxygenated and mild hypoxic state.
本研究的目的是评估硝酸甘油对哺乳动物心脏机械和代谢性能的影响，且不受外周血管和神经体液影响的干扰。用含有1微克/毫升酒精硝酸甘油或等量酒精的缓冲液灌注离体大鼠心脏。在体外和等容工作期间分析机械性能；所有心脏均处于轻度缺氧状态。通过起搏使心率保持恒定。在恒定的心房充盈压下，对照组和硝酸甘油组的舒张末期压力和计算得出的壁硬度无显著差异。用平均主动脉压定量的后负荷在两组中相同。缺氧显著降低了射血和等容工作期间的峰值收缩期左心室压力和dp/dt max（p<0.001），但硝酸甘油对其无影响。缺氧降低了心输出量、平均收缩期左心室压力、功、氧消耗和计算得出的效率（p<0.001）；缺氧状态增强了乳酸生成（p<0.001）。硝酸甘油在两种状态下对这些参数均无影响。结论是，在恒定心率、前负荷和后负荷下，硝酸甘油对完全氧合和轻度缺氧状态下心脏的机械性能以及有氧和无氧方式的能量生成均无影响。
