Differential Skeletal Response to Ovariectomy in Young and Old Rats

ABSTRACT

OBJECTIVE: The purpose of this study is to evaluate the loss of bone mineral density on ovariectomized (ovx) rat in young and old rats. METHOD: Total 110 Sprague-Dawley female rats which composed of 3 months aged 88 rats and 12 months aged 22 rats were used. They were divided randomly into 5 ovx groups (15 rats for each group) and 5 sham operation group (7 rats for each group). The bone mineral density was measured by Hologic 4,500 Fan Beam bone densitometry at the time of second postoperation week, 4th week, 8th week, and 16th week in young aged group and 4th, 8th week in old aged group. RESULTS: The bone mineral density in young ovx rats was decreased measured at 2 week, 4 week and 8 week, but not 16 week compared with that of sham operation rats (p0.05). CONCLUSION: For the purpose of osteoporosis inducing experiment, young aged rat is more reliable for the detection of bone density change than old aged rat and the bone mineral density change will be continued at least 16 week postovariectomy period.