Low-dose, ionizing radiation and age-related changes in skeletal microarchitecture
Joshua S Alwood1, Akhilesh Kumar, Luan H Tran
1Bone and Signaling Laboratory, NASA Ames Research Center, Mail Stop 236-7, Moffett Field, CA 94035, USA.
Journal of Aging Research
|May 10, 2012
Summary
Low-dose gamma radiation exposure, specifically 100 centigray (cGy), accelerates bone aging changes in mice. Doses of 1 or 10 cGy did not significantly impact skeletal aging markers.
Area of Science:
- Gerontology
- Radiation Biology
- Skeletal Biology
Background:
- Osteoporosis is a significant health concern in aging populations, characterized by progressive bone loss.
- High-dose ionizing radiation is known to induce bone changes similar to aging.
- The effects of lower radiation doses (≤100 cGy) on skeletal aging are less understood.
Purpose of the Study:
- To investigate whether low-dose gamma radiation exposure accelerates age-related structural changes in bone.
- To determine the dose-dependent effects of gamma radiation on bone microarchitecture.
Main Methods:
- Male C57BL/6J mice were exposed to total body gamma radiation (0, 1, 10, or 100 cGy).
- Bone microarchitecture was analyzed using microcomputed tomography at baseline, 1 month, and 4 months post-irradiation.
- Bone marrow cell differentiation was assessed ex vivo.
Main Results:
- Irradiation with 100 cGy caused transient bone microarchitectural changes within one month.
- These changes at 100 cGy were more pronounced over time compared to controls at 4 months.
- Lower doses (1 and 10 cGy) did not significantly alter bone microarchitecture.
- Gamma radiation did not affect ex vivo bone cell differentiation from marrow.
Conclusions:
- Acute ionizing gamma irradiation at 100 cGy exacerbates age-related microarchitectural bone changes.
- Lower doses (1-10 cGy) of gamma radiation did not show significant effects on skeletal aging markers in this study.
- These findings suggest a potential acceleration of skeletal aging by moderate doses of gamma radiation before the onset of osteoporosis.
More Related Videos
Related Concept Videos
01:29Bone Disorders
Aging and its effect on bone remodeling is the most common cause of bone disorders. In young and healthy people, bone deposition and resorption happen at an equal rate to maintain optimal bone health.
Bone deposition is also affected by the levels of sex hormones like estrogen and testosterone that promote osteoblast activity and bone matrix synthesis. When the level of these hormones decreases due to aging, it causes a reduction in bone deposition. As a result, bone resorption by osteoclasts...
Bone deposition is also affected by the levels of sex hormones like estrogen and testosterone that promote osteoblast activity and bone matrix synthesis. When the level of these hormones decreases due to aging, it causes a reduction in bone deposition. As a result, bone resorption by osteoclasts...
01:19The Effect of Aging on Tissues
Several body functions deteriorate with age. The external signs of aging are easily identifiable. For example, the skin becomes dry, less elastic, and thins out, forming wrinkles. The skin of the face begins to appear looser due to a decrease in the levels of elastic and collagen fibers in the connective tissue. Additionally, melanin production in the hair follicle decreases with age, resulting in gray hair. Moreover, the senses of sight and hearing decline, so glasses and hearing aids may...
02:59Biological Effects of Radiation
All radioactive nuclides emit high-energy particles or electromagnetic waves. When this radiation encounters living cells, it can cause heating, break chemical bonds, or ionize molecules. The most serious biological damage results when these radioactive emissions fragment or ionize molecules. For example, α and β particles emitted from nuclear decay reactions possess much higher energies than ordinary chemical bond energies. When these particles strike and penetrate matter, they produce ions...
01:40Bone Remodeling
Bone remodeling is a continuous and balanced process of bone resorption by osteoclasts and bone formation by osteoblasts. In adults, it helps maintain bone mass and calcium homeostasis. While mechanical stress can stimulate turnover as part of the normal maintenance and reparative process, several hormones also regulate bone remodeling.
01:09Changes in the Appendicular Skeleton with Age
The upper and lower limb initially develops as a small bulge called a limb bud, which appears on the lateral side of the early embryo. The upper limb bud appears near the end of the fourth week of development, with the lower limb bud appearing shortly after.
Initially, the limb buds consist of a core of mesenchyme covered by a layer of ectoderm. The ectoderm at the end of the limb bud thickens to form a narrow crest called the apical ectodermal ridge. This ridge stimulates the underlying...
Initially, the limb buds consist of a core of mesenchyme covered by a layer of ectoderm. The ectoderm at the end of the limb bud thickens to form a narrow crest called the apical ectodermal ridge. This ridge stimulates the underlying...
01:24X-ray Imaging
German physicist Wilhelm Röntgen (1845–1923) was experimenting with electrical current when he discovered that a mysterious and invisible "ray" would pass through his flesh but leave an outline of his bones on a screen coated with a metal compound. In 1895, Röntgen made the first durable record of the internal parts of a living human: an "X-ray" image (as it came to be called) of his wife’s hand. Scientists worldwide quickly began their own experiments with X-rays, and by 1900, X-ray was widely...