Effects of prednisone on bone mineral density and biomechanical characteristics of the femora and lumbar vertebras in rats.
OBJECTIVE
To explore effects of prednisone on the bone mineral density (BMD) and biomechanics of the femora and lumbar vertebras in rats.


METHODS
Twenty one 3-month-old male Sprague-Dawley rats weighing 226+/-12 g were randomly divided into basal control, age-matched and hormone groups. The rats in basal control group were killed at the beginning of the experiment without any treatment, and those in age-matched group were given oral normal saline (5 ml x kg(-1) x d(-1)) while the rats in hormone group received oral prednisone acetate (4.5 ml x kg(-1) x d(-1) twice a week) to establish osteoporotic models. The treatment for the latter 2 groups of rats lasted for 90 days, after which the BMD and mechanical measurements of the femurs and L5 vertebra were carried out by way of torsion, three-point bending and compression tests. The measurements were also conducted in the basal control group at the time indicated above.


RESULTS
In hormone group, the total BMD of the femora and L5 vertebra was decreased by 14.64%(P<0.01), and the BMD in the right and left distal femoral segments and the vertebra decreased by 21.42% (P<0.01), 19.62% (P<0.05) and 23.48%(P<0.01), respectively, in comparison with the control group. In the meantime, the loads of three-point bending test in hormone group was decreased by 17.1%(P<0.05), whereas the rest parameters tended to decrease as compared with the control group.


CONCLUSIONS
Chronic use of corticosteroid is more liable to cause bone mass loss in rat cancellous bone than in the cortical bone, and mechanical properties of the cortical and cancellous bone, especially those of the latter, will also decline, to give rise to easy bone fracture at the trabecular bone in osteoporotic conditions.
Liao
Jin-min
JM
Institute of Clinical Anatomy, First Military Medical University, Guangzhou 510515, China.
Li
Qing-nan
QN
Wu
Tie
T
Hu
Bin
B
Huang
Lian-fang
LF
Li
Zhong-hua
ZH
Zhao
Wei-dong
WD
Zhang
Mei-chao
MC
Zhong
Shi-zhen
SZ
D000818:Animals; D001696:Biomechanical Phenomena; D015519:Bone Density / Q000187:drug effects*; D005269:Femur / Q000187:drug effects*; D005938:Glucocorticoids / Q000009:adverse effects; D008159:Lumbar Vertebrae / Q000187:drug effects*; D008297:Male; D010024:Osteoporosis / Q000139:chemically induced*; D011241:Prednisone / Q000009:adverse effects*; D051381:Rats; D017207:Rats, Sprague-Dawley
D005938:Glucocorticoids; D011241:Prednisone