HYDROCARBONS 



357 



Benzpyrene — ^^ "BPX" i!LJ^ "BPF" 

 (4) 



(4) 



(BPX) 



(5) 



-> (BPF) 



(6) 



8-Hydroxy-3,4-benzpyrene 

 Fig. 6. The projected intermediate compounds in the metaboHsm of benzpyrene. ^'^ 



(3) In vitro, by postmortem autolysis. 



(4) In vitro, by adsorption on alumina. 



(5) In vitro, by heating in vacuo to a high temperature. 



(6) In vitro, by sublimation in vacuo. 



Chalmers and Kirby-^'' reported that approximately 1% of benzpyrene 

 which had been injected subcutaneously into rats was excreted unchanged 

 in the feces. Weil-Malherbe and Dickens^^^ reported that the rate of 

 elimination of 3,4-benzpyrene was dependent upon the solvent employed; 

 the faster the excretion, the greater was the incidence of sarcoma. When 

 synthetic tricaprylin in the presence of cholesterol was the medium used 

 as the solvent, a higher elimination rate and an increased tumor incidence 

 were noted in mice. In the presence of phospholipids, the ehmination 

 rate of the carcinogen was prolonged and the latent period of the sarcomas 

 was extended. Not only cholesterol but also cholestanol, sitosterol, and 

 a-tocopherol were later proved to accelerate the elimination rate of 3,4- 

 benzpyrene,-^^ while epicholestanol, coprostanol, epicoprostanol, stigmas- 

 terol, 7-dehydrocholesterol, and ergosterol were inactive in affecting the 

 course of excretion. 



b'. 1,2,5,6-Dibenzanthracene: This compound has been proved to be 

 a carcinogenic agent of considerable potency, capable of producing tumors 

 in mice, rats, chickens, and rabbits. ^''<' 



Le\'i and Boyland and^^* later Dobriner et al.^^^ isolated a dihydric phenol 



2" J. G. Chalmers and A. H. M. Kirby, Biochem. J., 34, 1191-1195 (1940). 



"8 H. Weil-Malherbe and F. Dickens, Cancer Research, 6, 171-178 (1946). 



"s F. Dickens and H. Weil-Malherbe, Biochem. J., 42, xxxiii (1948). 



*"> K. Stern and R. Willheim, Biochemistry of Malignant Tumors, Chemical Publishing 

 Co., Brooklyn, 1943, p. 174. 



»i K. Dobriner, C. P. Rhoads, and G. I. Lavin. Proc. Sac. Expll. Biol. Med., 4I, 67-09 

 (1939). 



