|Nielsen, Forrest - Frosty|
Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: 12/10/2000
Publication Date: 3/7/2001
Citation: Fohrman, K.K., Seaborn, C.D., Nielsen, F.H. 2001. Lead, silicon and their interaction affect bone composition [abstract]. The Federation of American Societies for Experimental Biology Journal. 15:A972.
Technical Abstract: Because lead (Pb) and Si both alter bone mineralization, we performed a study to ascertain the extent of these effects on rat bone. Male weanling Spraque-Dawley rats were randomly assigned to treatment groups of nine in a 2 X 4 factorially arranged experiment. The rats were fed a basal diet that contained 2 ug/g Si for three weeks. The independent treatment variables, per g fresh diet, were supplemental Si (as sodium metasilicate) at 0 and 10 ug and Pb at 0 and 35 ug. The supplemental Pb markedly increased the concentrations of Pb in plasma, liver, kidney, skull and femur. Dietary Si affected the bone mineral composition changes resulting from supplemental Pb. In the skull, calcium (Ca), phosphorus (P), and magnesium (Mg) concentrations were lower in Si-supplemented than Si- deprived rats not fed Pb. Supplemental Pb decreased the skull and femur concentration of Ca, P, and Mg, when dietary Si was low, but increased the concentration when dietary Si was adequate. As a result, when Pb was added to the diet, there was essentially no differences in femur concentrations of Ca, P, and Mg between Si-deprived and -adequate rats; in the skull, the changes caused by Pb supplementation were so marked that the difference in Ca, P, and Mg between Si-deprived and -adequate rats were actually the reverse of those when dietary Pb was low. Femur copper concentrations were markedly decreased by high dietary Pb, which suggests a negative effect on the organic matrix component of bone where Si is apparently of importance. This possibly explains the contrast effects of Pb on bone in the Si-deprived and -adequate rats.