Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: 11/7/2006
Publication Date: 4/1/2007
Citation: Nielsen, F.H. 2007. Boron deprivation increases plasma homocysteine, a factor negatively associated with bone composition and strength [abstract]. Journal of Federation of American Societies for Experimental Biology. 21(5):A125. Interpretive Summary:
Technical Abstract: Boron (B) deprivation decreases trabecular bone in vertebrae of rats. Elevated plasma homocysteine (Hcy) has been associated with decreased trabecular bone. S-adenosylmethionine, an intermediate in the formation of Hcy, has the highest known affinity for B of all mammalian biocompounds examined. Thus, the effect of B deprivation on plasma Hcy and cysteine (Cys) was determined. Because dietary n-3 fatty acids affect the response to B deprivation and decrease plasma Hcy, an additional experimental variable was dietary oil. Female weanling rats were fed diets containing 75 g corn oil (CO)/kg and 0.1 (B-def) or 3.1 (B-adq) mg B/kg for 75 d then bred. After weaning, 30 male pups continued on the diets fed their mothers; another 30 male pups were fed diets containing 0.1 or 3.1mg B/kg and 65 g fish oil (FO)/kg and 10 g linoleic acid/kg. Plasma and femurs were collected at 18 wk. B-def was confirmed by decreased femur B and B-def responses of decreased femur iron and magnesium. B-def increased plasma Hcy. Both B-def and CO vs. FO increased plasma Cys. Thus, the B-def rats fed CO had the highest plasma Cys. This group also had the lowest calcium and highest copper concentrations in the femur. The findings suggest that B and n-3 fatty acids influence sulfur amino acid metabolism differently. Changing metablic pathways involving cysteine may be partly responsible for the interaction between B and dietary oil affecting bone composition.