PART VI 



CARBOHYDRATE AND FATTY ACID 



METABOLISM 



A STUDY OF ACETONE METABOLISM USING 

 GLYCOGEN AND SERINE AS INDICATORS, AND 

 THE ROLE OF Ci-COMPOUNDS IN METABOLISM 



HARLJND G. WOOD 



The first experiments concerning the distribution of tracer 

 carbon in the ghicose unit of hver glycogen were reported in 

 1945 and showed that the normal rat fixes CO 2 in the 3 and 

 4 positions of the glucose (Wood, Lifson and Lorber, 1945). 

 The results were of special interest because they demonstrated 

 that it was possible to confirm in the intact aniinal concepts 

 of carbohydrate metabolism that had been based largely on 

 studies with enzyme preparations from a wide variety of 

 tissues. These concepts included the tricarboxylic acid cycle, 

 fixation of CO 2 in oxaloacetate, and the synthesis of glycogen 

 by the reversal of the reactions of anaerobic glycolysis. The 

 finding that CO 2 carbon occurred only in the 3 and 4 carbons 

 was most gratifying not only because it verified the predic- 

 tions arrived at by in vitro studies but because it showed the 

 possibilities for other similar in vivo studies. These experi- 

 ments marked the beginning of the use of the distribution 

 patterns of the tracer in glycogen as an indicator of metabolism 

 studied in vivo. Numerous experiments from several labora- 

 tories have yielded a body of information which permits 

 rather reliable deductions about mechanisms of intermediary 

 metabolism. 



227 



