The Effects of Zoledronic Acid Treatment and Endurance Exercise on Ovariectomy-induced Osteopenia in Wistar Rats

Background: This study investigated the effects of endurance exercise training and zoledronic acid (Zol) treatment on ovariectomy-induced osteopenia. Methods: : Middle-aged female Wistar rats were subjected to sham and ovariectomy surgeries and assigned to seven different groups according to Zol treatment doses and treadmill endurance exercise training; these were the Sham, Ovx, LowZ, HighZ, EXE, LowZ+EXE, HighZ+EXE groups. The subcutaneous (s.c.) doses of Zol for the LowZ and HighZ groups were 20 and 100 µg/kg, respectively. Total intervention period was 10 weeks. Results: : Both Zol treatment and exercise training significantly blunted ovariectomy-induced osteopenia in spongy bone (p<0.05). Zol treatments increased whole bone bending strength/energy as well as tissue-level toughness (p<0.05). The EXE and LowZ+EXE had higher levels of serum phosphorus as compared to other groups, suggesting higher bone metabolism activity. Additionally, the three exercise groups’ significantly lower serum triglycerides, leptin, IGF-1 and IGF-1/IGFBP-3 molar ratio, along with increased IGFBP-3. Conclusions: : Though exercise training did not demonstrate significantly synergistic or modifying effects to Zol-treated bone, results from energy, aging and bone related serum measurements indicate that exercise might reveal its benefits in later phases or at lower doses of bisphosphonate.