STRONTIUM RICKETS: BONE, CALCIUM, AND STRONTIUM CHANGES
In rats fed increasing Sr levels in the diet, inhibition of calcification occurred as seen by increased width of epiphyseal cartilage, presence of uncalcified bone matrix, and decreased ash weight of bone. With ash weight as an indicator of mineralization, inhibition of calcification became greater as the dietary Sr level increased. This inhibition was maximum when the Ca/Sr molar ratio in serum became <10/1. In contrast to ash weight, the percentage ash in bone was a less sensitive indicator of rachitic change, because both mineral and organic weight decreased proportionately, and consequently the percentage ash remained unchanged until high dietary levels of Sr were reached. Incorporation of Sr into bone varied, not with dietary Sr levels, but with the Ca/ Sr ratio. The two ions were treated similarly, for the decrease in Ca/Sr ratio in the bone was proportional to that in diet for both young and old rats. In growing animals, addition of new bone mineral was probably the most important mechanism whereby Sr became incorporated into ash, while in slowly growing rats ion exchange assumed a more important role. At low dietary levels of Sr, bone matrix formation decreased roughly proportionately to inhibition of calcification, but at higher levels uncalcified bone matrix became prominent. These results may be of significince to the problem of osteoporosis, for they demonstrate that disorder of calcification can be associated with decreased growth of bone matrix. This suggests that osteomalacic and antianabolic mechanisms are not mutually exclusive, but may be interrelated factors in the pathogenesis of osteoporosis. (BBB)
- Research Organization:
- Univ. of Melbourne
- NSA Number:
- NSA-18-000023
- OSTI ID:
- 4178857
- Journal Information:
- Australian Ann. Med., Journal Name: Australian Ann. Med. Vol. Vol: 10
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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