Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: December 10, 1999
Publication Date: March 15, 2000
Citation: Nielsen, F.H., Yokoi, K., Uthus, E.O. 2000. Dietary nickel alters the response of rats to deficient dietary pyridoxine, and to high dietary homocystine or methionine [abstract]. The Federation of American Societies for Experimental Biology Journal. 14:A539. Technical Abstract: Previous studies in our laboratory have shown that dietary nickel affects the response of rats to deficient dietary vitamin B12 and pyridoxine (B6). Both of these vitamins influence the metabolism of homocysteine, which has been associated with ischemic heart disease. Thus, an experiment was performed to examine the effect of dietary nickel on the response of groups of 8 male weanling Sprague-Dawley rats to luxuriant intakes of homocystine (Hcy), and its precursor, methionine (Met). The experiment was 2 x 2 x 3 factorially arranged with nickel supplemented at 0 and 1 mg/kg diet, B6 supplemented at 0 and 7.5 mg/kg diet, and a dietary amino acid supplement of none, 10 g/kg Hcy and 10 g/kg Met. The basal diet contained about 8 ng of nickel, 1.8 mg of B6 and 4.7 g of Met per kg. The only significant effect on final weight after 10 weeks was a depression with B6 deficiency. B6 deficiency also decreased plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Dietary nickel affected the ALT and AST response to amino acid supplementation. Both ALT and AST were decreased by Hcy and Met in nickel-deficient rats, but increased in nickel-supplemented rats. Dietary nickel also affected the plasma triglyceride response to Hcy and Met. Triglycerides were increased by Hcy and Met in nickel-deficient rats; in nickel-supplemented rats, Hcy and Met induced a small decrease. The findings suggest that nickel status can affect the consequences resulting from high circulating homocysteine.