A sensitive radioisotopic assay of pyruvate dehydrogenase complex in human muscle tissue

Anal Biochem. 1991 Nov 1;198(2):347-51. doi: 10.1016/0003-2697(91)90437-x.


A radioactive assay for the determination of pyruvate dehydrogenase complex activity in muscle tissue has been developed. The assay measures the rate of acetyl-CoA formation from pyruvate in a reaction mixture containing NAD+ and CoASH. The acetyl-CoA is determined as [14C]citrate after condensation with [14C]-oxaloacetate by citrate synthase. The method is specific and sensitive to the picomole range of acetyl-CoA formed. In eleven normal subjects, the active form of pyruvate dehydrogenase (PDCa) in resting human skeletal muscle samples obtained using the needle biopsy technique was 0.44 +/- 0.16 (SD) mumol acetyl-CoA.min-1.g-1 wet wt. Total pyruvate dehydrogenase complex (PDCt) activity was determined after activation by pretreating the muscle homogenate with Ca2+, Mg2+, dichloroacetate, glucose, and hexokinase. The mean value for PDCt was 1.69 +/- 0.32 mumol acetyl-CoA.min-1.g-1 wet wt, n = 11. The precision of the method was determined by analyzing 4-5 samples of the same muscle piece. The coefficient of variation for PDCa was 8% and for PDCt 5%.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetyl Coenzyme A / metabolism
  • Calcium / pharmacology
  • Carbon Radioisotopes
  • Dichloroacetic Acid / pharmacology
  • Enzyme Activation / drug effects
  • Glucose / pharmacology
  • Hexokinase / pharmacology
  • Humans
  • Magnesium / pharmacology
  • Muscles / drug effects
  • Muscles / enzymology*
  • Pyruvate Dehydrogenase Complex / chemistry*
  • Substrate Specificity


  • Carbon Radioisotopes
  • Pyruvate Dehydrogenase Complex
  • Acetyl Coenzyme A
  • Dichloroacetic Acid
  • Hexokinase
  • Magnesium
  • Glucose
  • Calcium