Background & Aims

Behavioural changes are more prevalent in special periods of a woman, when there are drastic variations in oestrogen levels, such as pregnancy, postpartum and menopause. It was demonstrated that oestrogen modulates the sensory response of peripheral and central neurons in female, male or castrated animals. Oestrogen exerts an antinociceptive action and models in ovariectomized female rodents demonstrate that low oestrogen levels induce mechanical and thermal hyperalgesia, which
is reversed with oestrogen therapy. The aim of this study is to evaluate the effect of repeated ovarian hyperstimulation (ROH) on nociceptive behaviour in female mice.

Methods

Female Swiss mice (20 – 30 g) receiving standard feed and water ad libitum were used. The mice were divided into two groups, a placebo group (Control) and a treated group (Treatment). Mice in the treated group received 7.5 IU of hMG (Menopur ™) intraperitoneally, followed by 5 IU of human chorionic gonadotropin (hCG, Choriomon ™) 48 h later. The mice in the Control group received saline solution intraperitoneally, in the same volume and time as the Treatment group. Ovulation induction was performed ten consecutive times, at intervals of one week. Thermal (hot plate test) and mechanical sensitivity of the whisker skin (Von Frey test) were carried out in both groups one week before the start of the experiment and one week after the end of this protocol.

Results

There was no difference (p>0.05) between the basal response between females in the Control and Treatment groups in the assessments of thermal and mechanical sensitivity. Repeated ovarian hyperstimulation did not affect (p>0.05) thermal and mechanical sensitivity.

Conclusions

Repeated ovarian hyperstimulation does not alter thermal- and mechanical-induced nociceptive behaviours in mice. The results highlight the need for more animal studies that can understand the mechanisms involved in nociceptive changes induced by ovulation-inducing drugs.

References

Chen Q, Zhang W, Sadana N, Chen X. Estrogen receptors in pain modulation: cellular signaling. Biol Sex Differ. 2021 Feb 10;12(1):22. doi: 10.1186/s13293-021-00364-5.
Duarte-Guterman P, Leuner B, Galea LAM. The long and short term effects of motherhood on the brain. Front Neuroendocrinol. 2019 Apr;53:100740. doi: 10.1016/j.yfrne.2019.02.004.
Zhang W, Wu H, Xu Q, Chen S, Sun L, Jiao C, Wang L, Fu F, Feng Y, Qian X, Chen X. Estrogen modulation of pain perception with a novel 17?-estradiol pretreatment regime in ovariectomized rats. Biol Sex Differ. 2020 Jan 9;11(1):2. doi: 10.1186/s13293-019-0271-5.

Presenting Author

Adriana Rolim Campos

Poster Authors

Adriana Barros

DSc

University of Fortaleza

Lead Author

E-mail

Olga Goiana Sampaio MD

Universidade de Fortaleza

Lead Author

E-mail

Sacha Aubrey Santos RPh

Universidade de Fortaleza

Lead Author

E-mail

Marina Damasceno PharmD

Universidade de Fortaleza

Lead Author

E-mail

Larissa Joventino

Universidade de Fortaleza

Lead Author

E-mail

Grayce Ellen Lima MSc

Universidade de Fortaleza

Lead Author

E-mail

Marcelo Cavalcante PhD

Universidade de Fortaleza

Lead Author

E-mail

Topics

  • Gender/Sex Differences