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Skeletal response to dietary calcium in a rat model simulating weightlessness

, : Skeletal response to dietary calcium in a rat model simulating weightlessness. Journal of Bone and Mineral Research 1(2): 191-197

Unweighting the hindlimbs of a rat by tail suspension leads to a decrease in bone in the unweighted hindlimbs, but not in the normally weighted forelimbs. We evaluated whether increments in dietary calcium could prevent this. Growing rats were fed diets ranging in calcium content from 0.1% to 2.4%. After the rats were suspended for two weeks, we found no differences between suspended and control animals fed the same diet with respect to calcium transport or serum levels of calcium, phosphorus, 1,25-dihydroxyvitamin D, and parathyroid hormone. In both groups, increasing dietary calcium reduced active intestinal calcium transport and serum 1,25-dihydroxyvitamin D levels. The calcium content of the tibia and lumbar vertebra (but not the humerus) was reduced in suspended rats compared to control rats fed the same diet. However, increasing dietary calcium increased the calcium content of all bones in both suspended and control animals. The bone formation rate at the tibiofibular junction (measured by double-label tetracycline) was reduced in the suspended animals compared to controls and was not altered by dietary calcium. However, the marrow area of the tibia, an indication of bone resorption, did not differ between suspended and control animals and was equally reduced in both groups when dietary calcium was increased. Our data suggest that the deleterious effects of skeletal unweighting on bone formation cannot be explained by changes in the calciotropic hormones and are not reversed by increments in dietary calcium. However, increasing dietary calcium can increase bone calcium, even in unweighted limbs, by decreasing bone resorption.


PMID: 3503537

DOI: 10.1002/jbmr.5650010205

Other references

Gold, R.H.; Mirra, J.M.; Remotti, F.; Pignatti, G., 1989: Case report 527: Giant bone island of tibia. Skeletal Radiology 18(2): 129-132

Rey J F.; Harvey R.F., 1977: Hormonal control of the sphincter of oddi. Delmont, J (Ed ) The Sphincter Of Oddi Proceedings Of The Third Gastroenterological Symposium Nice, France, June 8-9, 1976 Xii+259p Illus S Karger: Basel, Switzerland; New York, N Y , Usa Isbn 3-8055-2623-7 66-71

Konstantinov, O.; Gorchakovskaia, N.; Borisov, G.; Shipacheva, M., 1981: Evaluation of the content of DDT residues in herbacious vegetation after tick control treatments in taiga foci of tick-borne encephlitis. Meditsinskaia parazitologiia i parazitarnye bolezni: (1) 66-71

Fidder, A.; Noort, D.; De-Jong, L.P.A.; Benschop, H.P.; Hulst, A.G., 1996: N7-(2-hydroxyethylthioethyl)-guanine: A novel urinary metabolite following exposure to sulphur mustard. Archives of Toxicology 70(12): 854-855

Chiu, T.H.; Emdur, L.I.; Platt, D., 1974: Lipoteichoic acids from Streptococcus sanguis. Two lipoteichoic acids, membrane (MLTA) and wall (WLTA), have been purified from Streptococcus sanguis by Sepharose and Ecteola-cellulose column chromatographies and concanavalin A-conjugated Sepharose affinity column chromatography. The teichoic...

Rangel, M.Adriana.; Moreira, D.; Vila Real, M.; Santos, Fátima., 2016: Meningoradiculopathy Associated with Human Herpesvirus 7-A Virus with Potential to Cause Severe Neurologic Disease with Sequelae. We present a case report of a meningoradiculopathy associated with human herpesvirus 7, with long-term motor neurologic sequelae. It is important to consider human herpesvirus 7 as a potential pathogen of severe neurologic disease and sequelae in...

Tews, D.S.; Goebel, H.H., 1995: Expression of cell adhesion molecules in inflammatory myopathies. We examined the expression of cell adhesion molecules in 25 cases of inflammatory myopathies. Inflammatory myopathies showed upregulation of adhesion molecules. ICAM-1 was strongly expressed on endothelial cells as well as on fibroblasts and infil...

Hayes, J.M., 1972: Management of acute renal failure. Anaesthesia and Intensive Care 1(1): 65-69

D.Kruif, A., 1998: Stimulation of estrus using prostaglandins. Tijdschrift Voor Diergeneeskunde 123(6): 187-187

Steiner, W.R., 1933: Dr. William Beaumont, a Sketch. Yale Journal of Biology and Medicine 6(1): 1-8