HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 291/6/E1235    most recent 00237.2006v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by Nieman, K. M. Articles by Schalinske, K. L. Search for Related Content PubMed PubMed Citation Articles by Nieman, K. M. Articles by Schalinske, K. L.

Folate status modulates the induction of hepatic glycine N-methyltransferase and homocysteine metabolism in diabetic rats

¹Department of Food Science and Human Nutrition, Iowa State University, Ames, IA; ²Department of Food Science and Human Nutrition and the Division of Nutritional Sciences, University of Illinois, Urbana, Illinois; and ³Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, New York

Submitted 18 May 2006 ; accepted in final form 2 July 2006

A diabetic state induces the activity and abundance of glycine N-methyltransferase (GNMT), a key protein in the regulation of folate, methyl group, and homocysteine metabolism. Because the folate-dependent one-carbon pool is a source of methyl groups and 5-methyltetrahydrofolate allosterically inhibits GNMT, the aim of this study was to determine whether folate status has an impact on the interaction between diabetes and methyl group metabolism. Rats were fed a diet containing deficient (0 ppm), adequate (2 ppm), or supplemental (8 ppm) folate for 30 days, after which diabetes was initiated in one-half of the rats by streptozotocin treatment. The activities of GNMT, phosphatidylethanolamine N-methyltransferase (PEMT), and betaine-homocysteine S-methyltransferase (BHMT) were increased about twofold in diabetic rat liver; folate deficiency resulted in the greatest elevation in GNMT activity. The abundance of GNMT protein and mRNA, as well as BHMT mRNA, was also elevated in diabetic rats. The marked hyperhomocysteinemia in folate-deficient rats was attenuated by streptozotocin, likely due in part to increased BHMT expression. These results indicate that a diabetic state profoundly modulates methyl group, choline, and homocysteine metabolism, and folate status may play a role in the extent of these alterations. Moreover, the upregulation of BHMT and PEMT may indicate an increased choline requirement in the diabetic rat.

choline; phosphatidylethanolamine; betaine-homocysteine S-methyltransferase

This article has been cited by other articles:

				K. T. Williams, T. A. Garrow, and K. L. Schalinske Type I Diabetes Leads to Tissue-Specific DNA Hypomethylation in Male Rats J. Nutr., November 1, 2008; 138(11): 2064 - 2069. [Abstract] [Full Text] [PDF]

				K. T. Williams and K. L. Schalinske New Insights into the Regulation of Methyl Group and Homocysteine Metabolism J. Nutr., February 1, 2007; 137(2): 311 - 314. [Abstract] [Full Text] [PDF]