Effects of pyruvate on the metabolism and insulin resistance of obese Zucker rats

John L. Ivy, Miriam Y. Cortez, Resa M. Chandler, Heidi K. Byrne, Robert H. Miller

Research output: Contribution to journalArticlepeer-review

19 Scopus citations


Female obese Zucker rats aged 5 wk were randomly assigned to a control diet or one of two experimental diets. Experimental diets contained 6% of energy as pyruvate in the form of calcium-pyruvate (Ca-pyr) or 6% pyruvylglycine (pyr-gly). Diets were pair-fed according to the experimental group with the lowest food consumption. During the 3 wk of dietary treatment, Ca-pyr- and pyr-gly-fed rats gained significantly less weight, had a lower food-conversion efficiency, and maintained a higher resting oxygen consumption (mL · min-1 · kg-0.67) than control rats. Ca-pyr and pyr-gly also lowered the respiratory exchange ratio of the rats resulting in a 90% increase in their lipid oxidation and a 50% decrease in their carbohydrate oxidation. Glucose tolerance, assessed by an oral glucose load, was not different among treatments, but the insulin response of the pyr-gly- fed rats was significantly less than that of the control rats despite elevated plasma triglyceride concentrations in the pyr-gly-fed rats (control, 1.43 ± 0.16 vs pyr-gly, 3.76 ± 0.87 mmol/L). These results suggest that pyr-gly, like Ca-pyr, favorably alters the metabolism of obese Zucker rats. In addition, pyr-gly appeared to reduce the insulin resistance that develops spontaneously in obese rats.

Original languageEnglish (US)
Pages (from-to)331-337
Number of pages7
JournalAmerican Journal of Clinical Nutrition
Issue number2
StatePublished - Feb 1994
Externally publishedYes

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Nutrition and Dietetics


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