How Oxytocin Receptors Affect Uterine Contractions Differently Across the Mouse Reproductive Cycle

Uterine contractions in response to oxytocin were significantly larger during the estrous phase compared to the diestrous phase.

• The uterus showed no contractions in response to oxytocin during the diestrous phase.
• Numerous contractions were observed in the uterus during the estrous phase following oxytocin administration.
• The potency of oxytocin, as indicated by pD(2) values, differed significantly between the two ovulatory phases.
• Oxytocin receptor levels were similar in the uterus during both phases, suggesting other regulatory mechanisms are involved.

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