1993 Fiscal Year Final Research Report Summary
Analysis of bone morphometorical dynamics by the animal model of postmenopausal osteoporosis
| Project/Area Number |
03454355
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Orthopaedic surgery
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| Research Institution | University of Tsukuba |
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Principal Investigator |
AMAGAI Hitoshi Univ.of Tsukuba, Imst.Clin.Med.Sci., Assist.Prof., 臨床医学系, 講師 (70193018)
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| Project Period (FY) |
1991 – 1993
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| Keywords | osteoporosis / osteoporosis model / beagle dog / histomorphometry / single photon absorptiometry / osteoblast function / calficication / perimenopausal period |
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| Research Abstract |
To explain the effect of the menopause to the bone tissue, the animal model of the postmenopausal osteoporosis was used in this study. We researched the bone extracted from the model animal utilizing the bone morphometoric method and carried out the original plan.
RESULTS
1) From the experiment at ovariectomized beagle dogs, the bone metabolism after ovariectomy seemed identical with human postmenopausal bone which had been acquired at the University of Tsukuba before essentially. However, in the ovariectomized beagle dongs, the period when the defect of osteoblast activities, espetially the defect of thematrix product, was showed. From the results of humn bone morphometry, it was observed that the defect of osteoblast activities at perimenopausal period was not only decrease of matrix product but also calcification of osteoid. Such a change was seen only at female, was not seen at male.
2) There was not the defect of calcification nor matrix product after the menopause. Postmenopausal ca
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lcification of osteoid and matrix product was rather similar to the youth than the perimenopausal period. Therefore, decreasing of the bone at the perimenopausal period was more than that of postmenopausal period.
3) In the patients of osteoporosis, the first symptom would appear at perimenopausal period, the increase of bone quantity would be seen very little if they were treated and male patient is rare. From the above things, it is thought that the cause of osteoporosis were the small quantity of bone at premenopausal period, the decrease of bone quantity by the defect of osteoblast activity at perimenopausal period and the defect of osteoblast function at postmenopausal period.
4) In the osteoporosis, the bone is easy to be broken with minor trauma because of the thinning of cortex bone and the decrease of the bone strength. The experiment with the ribs of ovariectomized beagle dogs showed the mechanism of osteoporosis that the bone matrix product decreased and the dense cortical bone transformed into the loose cancelous bone. Less
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