A pilot exploring the impact of paternal puberty blocking on offspring voluntary wheel running
Authors: Phillips Kara , Davis Scotty , Hydock David 
Published: May 2024

Previous work from our lab has shown puberty blocking treatment in young female rats followed by discontinued use (or detransition) leads to decreased voluntary wheel running activity in their offspring. The purpose of the present study was to determine if puberty blocking and detransition in young male rats affects offspring voluntary wheel running activity. We hypothesized that offspring of previously puberty blocked male rats will have lower wheel running activity than offspring of control rats. Four week old, male Sprague-Dawley rats received either 100 μg of the gonadotropin releasing hormone agonist triptorelin daily as a puberty blocker or 0.9% saline daily as a control. At the end of the 4 week treatment period, injections ceased, and each male rat was paired with an age-matched female rat for breeding. The breeding period lasted approximately 8 weeks and resulted in pregnancy of each paired female. At 6 weeks of age, a portion of the offspring were randomly assigned to the following voluntary wheel running groups: male offspring of previously puberty blocked males (M-PBO, n=2), female offspring of previously puberty blocked males (F-PBO, n=2), male offspring of control males (M-CON, n=5), and female offspring of control males (F-CON, n=5). Offspring were housed in cages outfitted with voluntary running wheels, received food and water ad libitum, and were maintained on a12:12 hour light:dark cycle. Voluntary wheel running activity was monitored for 8 weeks, and between-group comparisons were made via Welch’s t-test. Voluntary wheel running activity is presented as number of wheel running rotations, and data are shown as mean ± standard error. For total wheel running activity over 8 weeks, M-PBO had significantly lower voluntary wheel running activity than M-CON (107,453 ± 50,683 rotations vs. 456,011 ± 62,970 rotations, respectively, p=0.0122). There were no differences observed, however, between F-PBO and F-CON for total 8-week wheel running activity (376,582 ± 1,847 rotations vs. 472,271 ± 116,017 rotations, p=0.4559). Additionally, M-PBO ran significantly less than M-CON in weeks 1, 2, 3, 6, 7, and 8 (Week 1: 5,606 ± 225 rotations vs. 17,824 ± 2,544 rotations, p=0.0084; Week 2: 11,537 ± 3,129 rotations vs. 51,882 ± 6,494 rotations, p=0.0025; Week 3: 10,157 ± 2,639 rotations vs. 79,257 ± 5,842 rotations, p=0.0001; Week 6: 15,816 ± 7,865 rotations vs. 64,425 ± 11,755 rotations, p=0.0207; Week 7: 14,068 ± 6,999 rotations vs. 58,112 ± 9,781 rotations, p=0.0178; Week 8: 13,234 ± 6351 rotations vs. 67,349 ± 16,142 rotations, p=0.0272, respectively). No differences were observed in weekly wheel running activity between F-PBO and F-CON. Based on the observed voluntary wheel running activity, puberty blocking male rats prior to breeding negatively impacted physical activity of male offspring but not female offspring. This is contrary to our previous work showing that puberty blocking treatment followed by detransition in female rats prior to breeding negatively impacted physical activity of both male and female offspring. Our hypothesis was therefore partially supported as M-PBO had significantly less wheel running activity than M-CON, but F-PBO and F-CON had similar wheel running activity. Supported by a University of Northern Colorado Provost's Seed Grant awarded to DSH. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.