SEX-DEPENDENT ANALGESIC EFFECTS OF OXYTOCIN IN MICE SUBJECTED TO THE HYPERALGESIC PRIMING MODEL

This study investigates sex diferences of the oxytocin effects on pain-related responses. Male and female Swiss-Webster mice were divided into eight groups by sex and treatment, receiving oxytocin (1 or 5 mg/kg), and assessed using the Von Frey test and the Grimace Mouse Scale. The results indicated that, in females, was observed a significant difference between the groups (F(3,49)=3.08;p=0.03) on the Von Frey test. Duncan's post hoc revealed that females treated with 1 mg/kg of oxytocin, both pre- and post-PGE2, had reduced mechanical hypersensitivity compared to the control group. Similarly, a significant difference between the groups was also observed on the grimace (F(3,45)=3.86;p=0.01). Duncan's post hoc indicated that females treated with 1 mg/kg of oxytocin, showed a decrease score compared to the control group. In males, the Von Frey test also showed a significant difference between the groups (F(3,48)=3.85;p=0.01). Duncan's post hoc revealed that males treated with 5 mg/kg of oxytocin post-PGE2 showed a reduction in mechanical hypersensitivity when compared to the control group. In addition, on the grimace, a significant difference was observed between the groups (F(3,47)=2.69;p=0.05), and Duncan's test indicated that animals treated with 5mg/kg of oxytocin, both pre- and post-PGE2, showed a reduction in scores compared to the control group. Oxytocin produces sex-dependent analgesic effects in a mouse hyperalgesic priming model. (CEUA/FCF/CAr 19/2022). Funding: FAPESP (2024/05877-2).