| Project/Area Number |
03670694
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Orthopaedic surgery
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| Research Institution | Akita Uiversity |
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Principal Investigator |
SATO Kozo Akita University School of Medicine, Professor, 医学部, 教授 (50004875)
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| Co-Investigator(Kenkyū-buntansha) |
WATANABE Wataru Akita University School of Medicine, Assistant, 医学部, 助手 (50167186)
SAITO Haruki Akita University School of Medicine, Assistant, 医学部, 助手 (00153817)
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| Project Period (FY) |
1991 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1993: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1992: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1991: ¥800,000 (Direct Cost: ¥800,000)
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| Keywords | EXPERIMENTAL OSTEOPOROSIS / RAT / OVARIECTOMY / DIABETES MELLITUS / PARATHYROID HORMONE / HISTOMORPHOMETRY / TARTRATE-RESISTANT ACID PHOSPHATASE / INCREASE OF BONE MASS / 卵巣摘出 / 糖尿病質荷 / ヒトPTH / 骨量 / 骨灰分量 |
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| Research Abstract |
(purpose)
We investigated the effects of intermittent administration o h-PTH on bone changes in ovariectomized rats (OVX) and streptozotocin (STZ) -induced diabetes mellitus (DM) rats.
(Materials and Methods)
Wistar rats, 7-8 months old, were used. Osteoporosis was induced by bilateral ovariectomy and diabetes mellitus which was established by an intraperitoneal injection of STZ.Vehicle-administered groups were used by control. Dose of administration of h-PTH is low (0.6mug/kg) or high dose (60.0 mug/kg). h-PTH or vehicle was injected subcutaneously six times a week for 4 weeks from 9 weeks after OVX and STZ administration. Tetracycline hydrochloride was injected intraperitoneally twice for double labeling. Histologically, the h-PTH-administered rats showed many long and thick trabeculae with extensive osteoid covering. By fluorescence microscopy, the extent of tetracycline-labeled surfaces was observed to be markedly increased in the h-PTH-administered rats. Tartrate-resistant acid phosphatase (TRAP) positive surface decreased in the h-PTH-administered rats. Bone mineral density and mineral contents were significantly lower in the b.1.control and vehicle groups than in the sham group. The PTH-administered groups showed the higher values compared with both vehicle and b.l.control groups. In bone histomorphometry, both bone volume and bone formation in the STZ group were marked reduced. The h-PTH-administered rats showed an increase in both bone volume and bone formation-related parameters. While the TRAP positive area and the number of osteoclasts decreased. In the h-PTH groups, bone formation was markedly activated, while bone resorption was slightly but not significantly reduced compared with in the with in the vehicle group. Accordingly the increase in bone volume was due to the acceleration of activated bone formation, as demonstrated by increases in osteoid surface, mineral apposition rate and bone formation rate, over the rate of bone resorption.
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