The Contractile Response to Oxytocin in Non-pregnant Rat Uteri Is Modified After the First Pregnancy.

During pregnancy, the uterus undergoes several modifications under the influence of hormonal and mechanical stimuli. We hypothesize that while most of these modifications are reverted during involution, some of the physiological properties of the uterus are permanently altered. To investigate this hypothesis, we conducted motility experiments to evaluate the contractility response of uterine tissue samples from non-pregnant virgin and proven breeder female rats to oxytocin (10 to 10 M).