INTERMEDIARY METABOLISM OF CHOLESTEROL 



407 



{4) Conversion to Pregnanediol 



There is now good evidence that cholesterol is the mother substance, 

 not only of choHc acid, but also of a number of the steroid hormones. ^^^ 

 Bloch^" demonstrated this interrelationship first in the case of pregnane- 

 diol. This investigator reported that, when deuteriocholesterol was given 

 to a woman in the eighth month of pregnancy, pregnanediol-3Q:,20a could 

 be isolated from the urine as the sodium salt of pregnanediol glucuronidate. 

 The isotope content of the pregnanediol was of the same order as that of the 

 cholesterol circulating in the blood. It was estimated that one-half to 

 two-thirds of the pregnanediol excreted arose by degradation of cholesterol, 

 probably via progesterone. The course of the reaction is illustrated in the 

 accompanying equation. 



CH3 



O 



HO' 



CH3 



/\ 



CH, 



-CH3 



Cholesterol 



0= 



Progesterone 



HO H 



Pregnanediol 

 The Formation of Pregnanediol from Cholesterol in the Female 



{6) Conversion to Adrenocortical Hormones 



Zaffaroni, Hechter, and Pincus^^^ were among the first to demonstrate 

 that both acetate and cholesterol can be transformed into the adrenocortical 

 steroid hormones. It was observed that cholesterol was the more efficient 

 in effecting the synthesis. Hechter et al.^^^ were later able to fractionate 



^^^ J. A. Lovern, The Chemistry of Lipids of Biochemical Significance, Methuen, Lon- 

 don; Wilev, New York, 1955. 



327 K. Bloch, /. Biol. Chem., 157, 661-666 (1945). 



328 A. Zaffaroni, O. Hechter, and G. Pincus, J. Am. Chem. Sac, 73, 1390-1391 (1951). 



329 O. Hechter, M. M. Solomon, A. Zaffaroni, and G. Pincus, Arch. Biochem. Biophys., 

 4^,201-214(1953). 



