| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1994: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1993: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Research Abstract |
IGF-I (Insulin like growth factor-I) is one of the most important growth factors, which are produced or secreted by osteoblasts. In this study, we investigated the alteration of IGF-I production in human osteoblasts with donor age. Moreover, collagen production, bone matrix protein which is enhanced by IGF-I was also investigated. Human osteoblasts of femoral periosteum at 10-12 PDL were cultured for 10 or 20 days in the presence of alpha-glycerophosphate and/or 1,25 (OH) _2D_3 after confluence.
1. IGF-I content (ng/mug DNA) released in medium from untreated cells increased with donor aging, especially more than 61 years old.
2. When cells were treated with 1,25 (OH) _2D_3, cells from elderly donors were inhibited with the treatment, but cells from 10 and 52 year-old donor were significantly enhanced with the treatment.
3. mRNA level of 1,25 (OH) _2D_3 receptor among these cell strains did not remarkable change.
4. mRNA level of IGF-I in cells from 88-year old donor was the lowest of various cell strains. Until now it is not clear whether the expression of IGF-I in cells from elderly donors is lower than other cell strains, or whether the stability of mRNA is weaker than other cell strains.
Collagen accumulation on extracellular matrix in osteoblasts increased with donor age. It is possible that cells from elderly donors accumulated much more collagen from younger donors by inhibiting collagen degradation.
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