Post-Stimulation Potentiation of Contractility in the Isolated Auricle of the Rabbit

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Abstract
The phenomenon of post-stimulation potentiation (PSP) was studied in auricular and ventricular strips of the rabbit. Factors such as voltage frequency and time of stimulation were studied. It was shown that both frequency and time of stimulation determine the extent of the PSP. Action potentials are not effected during PSP. The interval between rapid stimulation period and the post-stimulation contraction was studied. Lengthening this interval first increased PSP, and later reduced it. However, 4-5 minutes following the rapid stimulation PSP was still present. It is not possible to explain such long lasting effects on the basis of the Hajdu[long dash]Szent-Gyorgyi theory of K shifts into and out of the cell (Am. J. Physiol. 174: 371, 1953). It is postulated that a substance is produced during stimulation and utilized by the following contractions. This hypothesis can explain the Treppe phenomenon as well as post-stimulation potentiation.