Methotrexate effects on hepatic betaine levels in choline-supplemented and choline-deficient rats.
Groups of rats fed both choline-supplemented and choline-deficient diets were injected with methotrexate (MTX) at dose levels of 0.1 mg/kg/day and 0.2 mg/kg/day. Both doses produced lowered hepatic betaine levels in the choline-supplemented animals when compared with nontreated, pair-fed controls. Since betaine levels were very low in the livers of choline-deficient rats, MTX had no further effect on hepatic betaine in these animals. These data suggest that the betaine lowering seen in livers of choline-fed rats may be due to utilization as a means of compensating for the MTX-induced loss of N5 methyltetrahydrofolate for the vital methylation of homocysteine in methionine biosynthesis.
D000375:Aging; D000818:Animals; D001622:Betaine / Q000378:metabolism*; D002794:Choline / Q000494:pharmacology*; D002796:Choline Deficiency / Q000378:metabolism*; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D008715:Methionine / Q000378:metabolism; D008727:Methotrexate / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D001622:Betaine; D008715:Methionine; D002794:Choline; D008727:Methotrexate