Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: December 10, 2000
Publication Date: March 7, 2001
Citation: Yokoi, K., Uthus, E.O., Nielsen, F.H. 2001. Dietary sulfur amino acids and nickel deprivation affect the distribution of vitamin B6 vitamers in rats [abstract]. The Federation of American Societies for Experimental Biology Journal. 15:A973. Technical Abstract: The metabolism of sulfur amino acid (SAA) is influenced by dietary pyridoxine and nickel (Ni). The effect of dietary SAA, Ni and pyridoxine on the distribution of vitamin B6 vitamers in plasma and tissues of rats was determined. Weanling male Sprague-Dawley rats were assigned to groups of 12 in a factorially arranged experiment with dietary variables of supplemental SAA (none, 10 g/kg dl-methionine or 10 g/kg dl-homocystine), pyridoxine hydrochloride (0 or 7.5 mg/kg) and Ni (0 or 1 mg/kg). Urine, and blood and tissues (liver and muscle) were collected for vitamin B6 vitamer (pyridoxal phosphate, pyridoxamine phosphate, pyridoxal, 4- pyridoxic acid) analyses after 9 and 10 weeks on feeding, respectively. Dietary pyridoxine deprivation decreased all vitamin B6 vitamers in plasma, tissues and urine. Compared to animals without supplemental SAA, homocystine increased plasma pyridoxal phosphate; both methionine and homocystine increased liver pyridoxal. When supplemental pyridoxine was given, homocystine decreased urinary excretion of 4-pyridoxic acid. When no supplemental SAA was given, dietary nickel deprivation increased plasma PLP. When methionine was given, dietary nickel deprivation decreased plasma PLP. These results suggest that vitamin B6 metabolism is affected by dietary SAA supplementation and Ni deprivation.