Mantelli L, Manzini S, Ledda F
Arch Int Pharmacodyn Ther. 1984 Dec;272(2):225-35.
The influence of several inotropic interventions on the strength of the post-rest contraction (PCR) was studied in isolated guinea-pig ventricular strips. In preparations stimulated at 1 Hz and incubated in 3.6 mM Ca++, the PRC-maximum potentiation was obtained after a rest interval of 2 sec (optimum resting time: ORT); a post-rest potentiation was present until 15 sec of rest. An increase in stimulation rate and in Ca++ concentration induced a shift in the ORT towards 15-20 sec, and an increase in the potentiation of PRC. At a low stimulation rate (0.33 Hz) the PRC was lower than steady-state contraction (SSC) at all rest intervals tested. Phenylephrine (5 X 10(-6) M) did not modify the ORT either at 1 or 2.5 Hz, and reduced the height of PRC at 0.33, 1 and 2.5 Hz. These results are discussed in terms of the different effects induced by the various inotropic interventions on cellular calcium availability.
在离体豚鼠心室肌条上研究了几种变力性干预对静息后收缩（PCR）强度的影响。在以1Hz刺激并在3.6mM Ca++中孵育的标本中，在2秒的静息间隔（最佳静息时间：ORT）后获得了PRC - 最大增强；静息15秒时仍存在静息后增强。刺激频率和Ca++浓度的增加导致ORT向15 - 20秒偏移，并增加了PRC的增强。在低刺激频率（0.33Hz）下，在所有测试的静息间隔中PRC均低于稳态收缩（SSC）。去氧肾上腺素（5×10（-6）M）在1Hz或2.5Hz时均未改变ORT，并在0.33Hz、1Hz和2.5Hz时降低了PRC的高度。根据各种变力性干预对细胞钙可用性的不同影响对这些结果进行了讨论。
