Relationship between electrical and mechanical activity of the isolated term-pregnant human myometrium.

In order to study the relationship between electrical and mechanical activity of isolated human myometrium in late pregnancy three different techniques were employed: the sucrose gap model, stiff pressure electrodes and flexible suction electrodes. A high degree of concordance was found between the various methods with regard to the pattern of electrical activity. However, the suction electrode technique seemed advantageous from a practical point of view due to its simplicity and high reproducibility. In the human myometrium each contraction was typically adjoined by a single spike potential, although trains of spikes were occasionally observed during the initial phase of the contraction. This contrasted to the bursts of spikes accompanying both the rising phase and the plateau phase of contractions in the myometrial specimens from the pregnant and estrous rat. This indicates a fundamental difference in electro-mechanical coupling mechanisms in the human myometrium when compared to the most widely used animal model for electrophysiological studies.