Myoelectrical changes in the uterus of the sheep around parturition

摘要

Summary. Myoelectrical activity in the uterus of late-pregnant sheep was recorded by the chronic implantation of bipolar electrodes in the myometrium. Three distinct patterns of electrical activity were recognizable: irregular trains of action potentials (>120 sec), long spike bursts (7–120 sec), or short spike bursts (100 μV) or low (50–100 μV) amplitude. The duration of spike activity was expressed as the myoelectrical index (MI), i.e. the fraction of the hour during which a given category of activity is exhibited.