Pilot Study Examining Wheel Running Activity Of Offspring Of Puberty Blocked And Detransitioned Female Rats

The impact that puberty blocking treatment with eventual discontinuation (or detransition) has on reproductive and offspring health is not fully understood. PURPOSE: As part of a larger study, we examined differences in voluntary wheel running activity between offspring from detranstitioned female rats and offspring from control female rats. METHODS: Four week old female Sprague-Dawley rats received either daily 100 μg subcutaneous injections of the gonadotropin releasing hormone agonist (GnRHa) triptorelin as a puberty blocker (P, n = 6) or saline as a control (C, n = 6) for 28 days. Injections then discontinued and female rats were paired with adult male rats to assess fertility. Offspring (O) from the P and C females were then randomly assigned to the voluntary wheel running (WR) or sedentary groups (SED) at 4 weeks of age. Male (M) and female (F) O assigned to WR (M + WR + PO, n = 3; F + WR + PO, n = 3; M + WR + CO, n = 3; F + WR + CO, n = 3) were housed in cages outfitted with voluntary running wheels for 56 days, and O assigned to SED (M + SED + PO, n = 4; F + SED + PO, n = 4; M + SED + CO, n = 4; F + SED + CO, n = 4) were housed in standard cages for 56 days. RESULTS: A significant main parent treatment effect (p = 0.0213) and sex effect (p = 0.0228) was observed for the total 56-day WR distance with PO animals running less than CO and M running less than F (M + WR + PO, 158 ± 54 km; M + WR + CO, 378 ± 27 km; F + WR + PO 373 ± 58 km; F + WR + CO 738 ± 187 km), but there was no parent treatment x sex interaction (p = 0.4988). No significant main effects or interactions were observed in WR distances during Week 1, but significant parent treatment effects were observed in Weeks 2-5 with PO running less than CO (p = 0.0157, p = 0.0131, p = 0.0114, p = 0.0263, respectively). Significant main sex effects were also observed in Weeks 2, 3, and 4 with M running less than F (p = 0.0026, p = 0.0088 and p = 0.0169, respectively). No significant main effects or interactions were then observed in WR distances for Weeks 6-8 (p > 0.05). CONCLUSIONS: Male and female offspring from detransitioned female rats had overall lower WR activity than their respective control counterparts suggesting that physical activity levels may be impacted by disruption in maternal reproductive development.