MECHANISM OF PARATHYROID HORMONE ACTION 587 



SlMMAUY 



We propose that an excess of parathyroid hormone inckices an 

 increased production of CO2 from gkicose or metaboHtes of glucose 

 by cells in bone. This theory is in accord with data from many in- 

 dependent studies. Of the various h}potheses posed to explain the 

 mechanism of action of parathyroid hormone, this concept explains 

 the present evidence in a more satisfactory manner than theories 

 based on the accumulation of citrate or lactic acid. 



Acknowledgments. These studies were supported in part by Grants 

 D-836, D-1197, D-1523, and A-1132 from the United States Public Health 

 Service. 



We acknowledge the technical assistance of Mr. Raymond Newman, 

 Miss Anna Smaich, and Mrs. Betty Young. 



References 



Balogh, K., Jr., Dudley, H. R., and Cohen, R. B. 1961. Oxidative enzyme 

 activity in skeletal cartilage and bone: A histochemical study. Lab. 

 Invest., 10, 839-845. 



Borle, A. B., Nichols, N., and Nichols, C, Jr. 1960. Metabolic studies of 

 • bone in vitro. II. The metabolic patterns of accretion and resorption. 

 /. Biol. Chem., 235, 1211-1214. 



Cohn, D. V. 1962. Unpublished data. 



Cohn, D. v., and Forscher, B. K. 1961. The effect of parathyroid hor- 

 mone on the oxidation of carbohydrate by bone. Biochim. et Biophys. 

 Acta, 52, 596-599. 



Cohn, D. v., and Forscher, B. K. 1962fl. Aerobic metabolism of glucose 

 by bone. /. Biol. Chem., 237, 615-618. 



Cohn, D. v., and Forscher, B. K. 1962Z?. Effect of parathyroid extract on 

 the oxidation in vitro of glucose and the production of C^^02 by 

 bone and kidney. Biochim. et Biophys. Acta, 65, 20-26. 



Cohn, D. v., and Forscher, B. K. 1962c. The influence of parathyroid ex- 

 tract on the production of CO2 from glucose by bone and kidney. 

 Federation Proc, 21, 207 (abstract). 



Firschein, H., Martin, C, Mulryan, B. J., Strates, B., and Neuman, W. F. 

 1958. Concerning the mechanism of action of parathyroid hormone. 

 I. Ion-gradients. /. Am. Chem. Soc, 80, 1619-1623. 



Kenny, A. D., Draskoczy, P. R., and Coldhaber, P. 1959. Citric acid pro- 

 duction bv resorbing bone in tissue culture. Am. J. Physiol., 197, 

 502-504. 



