| Co-Investigator(Kenkyū-buntansha) |
TSUJIMURA Atsushi Kyoto prefectural University of Medicine, Medicine, research associate, 医学部, 助手 (50236890)
HIRASAWA Yasusuk Kyoto prefectural University of Medicine, Medicine, professor, 医学部, 教授 (40079851)
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| Budget Amount *help |
¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 2000: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1999: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Research Abstract |
We have isolated osteoblast stimulating factor-1 (osf-1), that expressed in osteoblasts, and made transgenic mice over expressing osf-1 to investigate the effect to isotopic osteogenesis. Osf-1 over-expressing transgenic mice increased in bone mineral content, bone mineral density, and bone strength than wild type mice. Ovariectomized osf-1 over expressing mice, which are model of osteoporosis caused by estrogen deficiency, kept as the same bone volume as the sham operated wild type mice.
Mating male mice expressing homozyous osf-1, with wild type female mice, we got osf-1 heterozygous littermates. Next, we mated the heterozygous male and the heterozygous female littermates, and got another littermates which had osf-1 gene or not. We used 108 female littermates to examine the bone strength. 14-week-old mice were operated, half number of them were ovariectomized and another half number of them were sham-operated. As a result, we gained 42 mice having transgene and ovariectomized, 11 mice having no transgene and ovariectomized, 46 mice having transgene and sham-operated, 9 mice being negative with transgene and sham-operated. We excised femora of these mice at the age of 28-week-old, and evaluated their failure load of whole femora by three point bending test. The span between the supprts was 9 mm long, and the cross-head-speed was 0.5 mm/min.
In sham-operated mice groups, comparing with the transgenic mice and the wild type mice, by the value of failure load/body weight^2/3, the value of the transgenic mice tend to be stronger than that of the wild ones. (p=0.2175) Failure load per unit cross was approximated by that per body weight^2/3.
We can suggest the posibility that osf-1 over expression transgenic mice with increasing bone volume are also increasing their bone strength.
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