LIPID CONTENT AND COMPOSITION OF ANIMAL 561 



phasized the value of deuterium and of tritium 213 from a theoretical stand- 

 point. Deuterium oxide has been shown experimentally to give results 

 which appear reasonable on the basis of other data. 210 - 212 - 215-220 It has 

 been shown that labile hydrogen in organic compounds in the body ex- 

 changes with deuterium. 213,221,222 However, Hevesy and Jacobsen 223 esti- 

 mated this labile hydrogen to be equivalent to only 0.5 to 2.0% of the body 

 weight as water. Schloerb and co-workers 219 showed that the heavy water 

 space in the body exceeds the total body water by about 1% of the body 

 weight ; this probably accounts for the discrepancy due to labile hydrogen 

 exchange. 



(c') Antipyrine. — The dilution of non-physiologic compounds in the body 

 has likewise been employed for the calculation of body water, and indirectly 

 for the estimation of body fat. One of the most satisfactory substances 

 for this purpose appears to be antipyrine (l,5-dimethyl-2-phenyl-3-pyrazo- 

 lone), which has been used as an antipyretic since 1883. Brodie and as- 

 sociates 204,224 reported that antipyrine is uniformly distributed in the water 

 of various tissues. It is relatively non-toxic, 166,204 readily determined, and 

 only slowly metabolized by man. 166 The total body water in normal men, 

 as estimated by the use of antipyrine, agreed well with that calculated by 

 the use of heavy water, although less satisfactory results were obtained in 

 the case of edematous patients. The values obtained for the fat content 

 as calculated from the water content (estimated by the antipyrine method) 

 corresponded well with those based upon measurements of density. 194 Anti- 

 pyrine has given good results in the hands of many investigators 194,196, 225 ~ 228 



215 L. B. Flexner, A. Gellhorn, and M. Merrell, /. Biol. Chem., 144, 35-40 (1942). 



216 L. B. Flexner, W. S. Wilde, N. K. Proctor, D. B. Cowie, G. J. Vosburgh, and L. M. 

 Hellman, J. Pediat., 80, 413-415 (1947). 



217 F. D. Moore, Surg. Gynecol. ObsteL, 86, 129-147 (1948). 



218 V. Hollander, P. Chang, and F. W. Co Tui, J. Lab. Clin. Med., 34, 680-687(1949). 



219 P. R. Schloerb, B. J. Friis-Hansen, I. S. Edelman, A. K. Solomon, and F. D. Moore, 

 J. Clin. Invest., 29, 1296-1310 (1950). 



220 J. D. Hardy, P. K. Sen, and D. L. Drabkin, Surg. Gynecol. ObsteL, 93, 103-106 

 (1951). 



221 A. Krogh and H. H. Ussing, Skand. Arch. Physiol, 75, 90-104 (1936). 



222 H. H. Ussing, Skand. Arch. Physiol, 78, 225-241 (1938). 



223 G. Hevesy and C. F. Jacobsen, Acta Physiol. Scand., 1, 11-18 (1940). 



224 B. B. Brodie, J. Axelrod, R. Soberman, and B. B. Levy, J. Biol Chem., 179, 25-29 

 (1949). 



225 R. Soberman, B. B. Brodie, B. B. Levy, J. Axelrod, V. Hollander, and J. M. 

 Steele, J. Biol. Chem., 179, 31-42 (1949). R. J. Soberman, Proc. Soc. Exptl. Biol. Med., 

 71, 172-173 (1949). 



226 M. Herrold and L. A. Sapirstein, Proc. Soc. Exptl Biol Med., 79, 419-421 (1952). 



227 J. M. Steele, E. Y. Berger, M. F. Dunning, and B. B. Brodie, Am. J. Physiol, 162, 

 313-317(1950). 



228 G. W. Dupertuis, G. C. Pitts, E. F. Osserman, W. C. Welham, and A. R. Behnke, 

 J. Applied Physiol, 4, 364-367 (1951). 



