A new method for the assay of tissue. S-adenosylhomocysteine and S-adenosylmethione. Effect of pyridoxine deficiency on the metabolism of S-adenosylhomocysteine, S-adenosylmethionine and polyamines in rat liver.
The hepatic synthesis and accumulation of S-adenosylhomocysteine, S-adenosylmethionine and polyamines were studied in normal and vitamin B-6-deficient male albino rats. A method involving a single chromatography on a phosphocellulose column was developed for the determination of S-adenosylhomocysteine and S-adenosylmethionine from tissue samples. Feeding the rat with pyridoxine-deficient diet for 3 or 6 weeks resulted in a four- to five-fold increase in the concentration of S-adenosylhomocysteine, whereas that of S-adenosylmethionine was only slighly elevated. The concentration of putrescine was decreased to half, that of spermidine was somewhat decreased and that of spermine remained fairly constant. The activities of L-ornithine decarboxylase, S-adenosyl-L-methionine decarboxylase, L-methionine adenosyltransferase and S-adenosyl-L-homocysteine hydrolase were moderately increased. S-Adenosylmethionine decarboxylase showed no requirement for pyridoxal 5'-phosphate. The major effect of pyridoxine deficiency of S-adenosylmethionine metabolism seems to be a block in the utilization of S-adenosylhomocysteine, resulting in the accumulation of this metabolite to a concentration that may inhibit biological methylation reactions.
D012437:Adenosylmethionine Decarboxylase / Q000378:metabolism; D000818:Animals; D002845:Chromatography / Q000379:methods*; D006710:Homocysteine / Q000031:analogs & derivatives*; D008099:Liver / Q000378:metabolism*; D008297:Male; D011073:Polyamines / Q000378:metabolism*; D051381:Rats; D012435:S-Adenosylhomocysteine / Q000096:biosynthesis / Q000378:metabolism*; D012436:S-Adenosylmethionine / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism*; D013997:Time Factors; D026681:Vitamin B 6 Deficiency / Q000378:metabolism*
D011073:Polyamines; D006710:Homocysteine; D012436:S-Adenosylmethionine; D012435:S-Adenosylhomocysteine; D012437:Adenosylmethionine Decarboxylase