An in vitro study on spontaneous myometrial contractility in the mare during estrus and diestrus

Gaby Hirsbrunner, Martin Reist, Suzana S. Couto, Adrian Steiner, Jack Snyder, Elisabeth Vanleeuwen, Irwin Liu

Research output: Contribution to journalArticlepeer-review

11 Scopus citations


Uterine smooth muscle specimens were collected from euthanatized mares in estrus and diestrus. Longitudinal and circular specimens were mounted in organ baths and the signals transcribed to a Grass polygraph. After equilibration time and 2 g preload, their physiologic isometric contractility was recorded for a continuous 2.0 h. Area under the curve, frequency and time occupied by contractions were studied. Differences between cycle phases, between muscle layers, and over the recorded time periods were statistically evaluated using linear mixed-effect models. In the mare, physiologic contractility of the uterus decreased significantly over time for all variables evaluated (time as covariate on a continuous scale). For area under the curve, there was a significant effect of muscle layer (longitudinal > circular). For frequency, higher values were recorded in estrus for circular smooth muscle layer, whereas higher values were seen in longitudinal smooth muscle layers during diestrus. In longitudinal layer and in diestrus, more time was occupied by contractions than in circular layer, and in estrus. This study is describing physiologic myometrial motility in the organ bath depending on cycle phase.

Original languageEnglish (US)
Pages (from-to)517-527
Number of pages11
Issue number3
StatePublished - Feb 1 2006


  • Cycle phase
  • Mare
  • Myometrium
  • Organ bath
  • Physiology

ASJC Scopus subject areas

  • Small Animals
  • Food Animals
  • Equine
  • Animal Science and Zoology


Dive into the research topics of 'An in vitro study on spontaneous myometrial contractility in the mare during estrus and diestrus'. Together they form a unique fingerprint.

Cite this