Mn. Horcajada-molteni et al., Treadmill running starting 3 months after orchidectomy restores femoral bone mass in rats, EUR J A PHY, 79(3), 1999, pp. 251-259
Citations number
61
Categorie Soggetti
Physiology
Journal title
EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY AND OCCUPATIONAL PHYSIOLOGY
The present study was designed to provide data on the effects on femoral bo
ne of endurance training starting only 3 months after orchidectomy in rats.
A total of 70 Wistar male rats were used at 8 weeks of age. On day 0 of th
e experiment, 10 rats were killed by cervical dislocation to be used as fir
st controls. Among the 60 other animals, half was surgically castrated (CX)
or sham operated (SH). On day 90, 10 CX and 10 SH were killed and used as
intermediary controls (ICX and ISH). Among the other 20 CX and 20 SH, 10 wi
thin each group (CXE, SHE) were selected for treadmill running (60% maximal
oxygen uptake, 1h . day(-1), 5 days . week(-1) for 12 weeks). The 20 other
rats were used as sedentary controls (CXR, SHR) and killed (as runners) on
day 180. On day 90 femoral bone density (BMD) and mineral content (BMC) we
re lower in ICX than in ISH. On day 180 total femoral BMD was lower in CXR
than in CXE. Simultaneously metaphyseal femoral BMD was lower in CXR than i
n CXE, SHR or SHE. Furthermore, at that time, no significant difference con
cerning BMD and BMC was observed between SHR and CXE. This would indicate t
hat treadmill running starting only 3 months after orchidectomy is able to
restore BMD and BMC to control values, mainly by inhibiting bone resorption
(as shown by decreased urinary deoxypyridinoline excretion in CXE) without
decreasing osteoblastic activity (evaluated by plasma osteocalcin concentr
ation).