Dissociation of bone mineral density from age-related decreases in insulin-like growth factor-I and its binding proteins in the male rat
| Autor: | F. D. Thomas, Sinan Adiyaman, Robert A. Richman, Mark R. Benedict, David C. Ayers, V. Dhar, J. D. Calore |
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| Rok vydání: | 1994 |
| Předmět: |
Male
medicine.medical_specialty Aging Bone density medicine.medical_treatment Insulin-like growth factor-binding protein Bone and Bones Insulin-like growth factor Bone Density Internal medicine medicine Animals Insulin-Like Growth Factor I Bone mineral biology Growth factor medicine.disease Somatomedin Radioligand Assay Rats Inbred F344 Rats Specific Pathogen-Free Organisms Osteopenia Bone Diseases Metabolic Endocrinology biology.protein Carrier Proteins |
| Zdroj: | Journal of gerontology. 49(5) |
| ISSN: | 0022-1422 |
| Popis: | We evaluated the possibility that age-related decreases in circulating and/or bone-associated insulin-like growth factor-I (IGF-I) and its binding proteins (BPs) were associated with the development of osteopenia in 8-, 16-, and 24-month-old specific pathogen-free Brown Norway/Fischer 344 male rats. We measured bone mineral densities (BMD) of femurs by dual-energy x-ray absorptiometry. IGFs and IGFBPs were extracted from bone and separated by molecular exclusion HPLC before quantitation by specific radioligand assays. BMD did not change significantly between 8 and 24 months of age. IGF-I levels decreased by about 30% between 8 and 24 months in both serum and bone. Similarly, both circulating and bone-derived IGFBPs also declined (30% and 60%, respectively) with age. Thus, maintenance of femoral BMD throughout most of the adult rat life span was dissociated from the age-related decline in circulating and bone-associated IGF-I and IGFBPs. |
| Databáze: | OpenAIRE |
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