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Posts Tagged ‘hepatic lipogenesis’

Relationship between Adiposity and High Fructose Intake Revealed

Reporter: Larry H Bernstein, MD, FCAP

 

Dietary Fructose Feeding Increases Adipose Methylglyoxal Accumulation in Rats in Association with Low Expression and Activity of Glyoxalase-2

Christopher Masterjohn 1,2email, Youngki Park 1email, Jiyoung Lee 1email, Sang K. Noh 3email, Sung I. Koo 1email and Richard S. Bruno 1,4,* email
1 Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269, USA 2 Department of Comparative Biosciences, University of Illinois, Urbana, IL 61801, USA 3 Department of Food and Nutrition, Changwon National University, Changwon 641-773, Korea 4 Human Nutrition Program, Department of Human Sciences, The Ohio State University, Columbus, OH 43210, USA
Nutrients 2013, 5(8), 3311-3328;    http://dx.doi.org/10.3390/nu5083311

Abstract

  1. Methylglyoxal is a precursor to advanced glycation endproducts that may contribute to diabetes and its cardiovascular-related complications.
  2. Methylglyoxal is successively catabolized to d-lactate by glyoxalase-1 and glyoxalase-2.

The objective of this study was to determine whether dietary fructose and green tea extract (GTE) differentially regulate methylglyoxal accumulation in liver and adipose, mediated by tissue-specific differences in the glyoxalase system.

We fed six week old male Sprague-Dawley rats a low-fructose diet (10% w/w) or a high-fructose diet (60% w/w) containing no GTE or GTE at 0.5% or 1.0% for nine weeks.

Fructose-fed rats had higher (P < 0.05) adipose methylglyoxal, but GTE had no effect. Plasma and hepatic methylglyoxal were unaffected by fructose and GTE. Fructose and GTE also had no effect on the expression or activity of glyoxalase-1 and glyoxalase-2 at liver or adipose.

  • Regardless of diet, adipose glyoxalase-2 activity was 10.8-times lower (P < 0.05) than adipose glyoxalase-1 activity and 5.9-times lower than liver glyoxalase-2 activity.
  • Adipose glyoxalase-2 activity was also inversely related to adipose methylglyoxal (r = −0.61; P < 0.05).
  • These findings suggest that fructose-mediated adipose methylglyoxal accumulation is independent of GTE supplementation and that its preferential accumulation in adipose compared to liver is due to low constitutive expression of glyoxalase-2.

Keywords: fructose; glyoxalase I; glyoxalase II; pyruvaldehyde; rats; Sprague-Dawley

Masterjohn C, Park Y, Lee J, Noh SK, Koo SI, Bruno RS. Dietary Fructose Feeding Increases Adipose Methylglyoxal Accumulation in Rats in Association with Low Expression and Activity of Glyoxalase-2. Nutrients. 2013; 5(8):3311-3328. EISSN 2072-6643 Published by MDPI AG, Basel, Switzerland

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