Scheerboom J E, Van Adrichem P W, Taverne M A
Vet Res Commun. 1987;11(3):253-69. doi: 10.1007/BF00570923.
With electromyography and strain gauges the uterine motility of the sow during the oestrous cycle and early pregnancy was studied. Special attention was paid to characterization of myometrial activity at the time of intra-uterine migration of blastocysts. From recordings of 4 animals (3 became pregnant) 3 types of electrical spiking activity (each could be correlated with an elevation of the strain gauge tension) were discerned. Two of them appeared regularly and were suitable for analysis: "High Voltage Slow Acticity" (with relative high amplitude and low frequency of spikes) and "Low Voltage Fast Activity" (with relative low aplitude and high frequency of spikes). The sexual status markedly influenced myometrial activity: during proestrus and oestrus only one type of electrical activity was present whereas the myoelectrical complex (an episode of this activity and the subsequent interval of inactivity) was shorter than 10 min. During dioestrus the myoelectrical complex was longer than 10 min and "High Voltage Slow Activity" (solely on the cervix and bifurcation) and "Low Voltage Fast Activity" occurred simultaneously in episodes which mainly appeared to originate on the bifurcation. The characteristics of uterine activity during pregnancy were similar to those of a cyclic sow until day 12. It was only on day 12 that gestation appeared from an increased frequency of myoelectrical complexes. It is concluded that "Low Voltage Fast Activity" as it was found on the uterine horn at days 8-9 might be involved in the process of intra-uterine migration of blastocysts. In cyclic and in pregnant animals the patterns of "Low Voltage Fast Activity" were similar. Therefore, the occurrence of "Low Voltage Fast Activity" is independent of the actual presence of blastocysts. It seems to be exhibited in dependence on the ovarian hormones.
通过肌电图和应变仪研究了母猪在发情周期和妊娠早期的子宫运动。特别关注了胚泡在子宫内迁移时子宫肌层活动的特征。从4只动物（3只怀孕）的记录中，识别出3种电尖峰活动类型（每种都与应变仪张力升高相关）。其中两种活动规律出现且适合分析：“高压慢活动”（尖峰幅度相对较高且频率较低）和“低压快活动”（尖峰幅度相对较低且频率较高）。性状态对子宫肌层活动有显著影响：在发情前期和发情期，仅存在一种电活动类型，而肌电复合波（这种活动的一个片段及随后的静止间隔）短于10分钟。在间情期，肌电复合波长于10分钟，并且“高压慢活动”（仅在子宫颈和子宫分叉处）和“低压快活动”同时出现，这些片段主要起源于子宫分叉处。直到第12天，怀孕期子宫活动的特征与发情周期母猪的相似。仅在第12天，妊娠从肌电复合波频率增加中显现出来。结论是，在第8 - 9天子宫角发现的“低压快活动”可能参与了胚泡在子宫内的迁移过程。在发情周期和怀孕动物中，“低压快活动”的模式相似。因此，“低压快活动”的出现与胚泡的实际存在无关。它似乎是依赖于卵巢激素而表现出来的。
