Chiba S
Eur J Pharmacol. 1976 Dec;40(2):225-32. doi: 10.1016/0014-2999(76)90056-x.
The canine right atrium was perfused with arterial blood led from a carotid artery of the heparinized support dog and suspended in a bath filled with blood. In 5 non-spontaneously beating preparations, the frequency-force relationship was investigated by electric stimulation at a frequency range from 0.017 to 3 Hz. At a low frequency level, a large peak tension developed. At 0.5 Hz, minimum values of developed tension were obtained. At a range of 0.5-3 Hz, the developed tension increased with the frequency. Higher frequencies than 4 Hz usually caused pulsus alternans. The staircase phenomena were not influenced by treatment with propranolol or atropine. Therefore, there may be no participation of the autonomic nerve stimulation on the frequency-force relationship. Effects of pentobarbital, (+/-)-verapamil and manganese on the frequency-force relationship were investigated with both the blood-perfused, isolated atrium preparations and isolated ventricular preparations. Pentobarbital and manganese chloride produced a uniform depression of the developed tension at all frequencies but the depression with (+/-)-verapamil was greater at higher frequencies in both atrial and ventricular muscles.
犬右心房用来自肝素化支持犬颈动脉的动脉血灌注，并悬挂在充满血液的浴槽中。在5个非自发搏动的标本中，通过在0.017至3Hz的频率范围内进行电刺激来研究频率-力关系。在低频水平时，出现一个大的峰值张力。在0.5Hz时，获得了所产生张力的最小值。在0.5至3Hz范围内，所产生的张力随频率增加。高于4Hz的频率通常会引起交替脉。阶梯现象不受普萘洛尔或阿托品治疗的影响。因此，自主神经刺激可能不参与频率-力关系。用血液灌注的离体心房标本和离体心室标本研究了戊巴比妥、（±）-维拉帕米和锰对频率-力关系的影响。戊巴比妥和氯化锰在所有频率下均使所产生的张力均匀降低，但（±）-维拉帕米在心房和心室肌中在较高频率下的降低作用更大。
