XXll CONTENTS 



VII. The Metabolism of Branched-Chain Acids, Hydroxy and Keto 

 Acids, Dicarboxylic Acids, Tricarboxylic Acids, Fatty Acid Amides, 

 Fatty Acid Aldehydes, and Hydrocarbons {continued) 



(d) Halogenated Aromatic Hydrocarbons 344 



I). Naphthalene and Related Products 346 



(a) Naphthalene 346 



a'. Oxidation of Naphthalene to Naphthol 347 



b'. Formation of L-a-Naphthylmercapturic Acid 347 



c'. l,2-Dihydro-2-Naphthol as an Oxidation Product 348 



d'. l,2-Dihydroxy-l,2-Dihydronaphthalene as a Product of 



Naphthalene Metabolism 348 



e'. Resume of the Metabolism of Naphthalene 349 



(b) Hydrogenated Naphthalenes 350 



c. Three- Ringed Hydrocarbons 351 



(a) Anthracene 351 



a'. Dihydroxydihydroanthracene 351 



1)'. Anthrylmercapturic Acid 352 



c'. Anthraquinone 352 



(b) Phenanthrene 353 



(c) Acenaphthene 353 



d. Higher Aromatic Hydrocarbons 354 



(a) Four-Ringed Hj'^drocarbons 354 



a'. Chrysene 354 



b'. 1,2-Benzanthracene 354 



(b) Five-Ringed Hydrocarbons 355 



a'. 3,4-Benzpyrene 355 



b'. 1,2,5,6-Dibenzanthracene 357 



VIII. The Metabolism of Cholesterol and Related Sterols in the Animal 



Body 361 



1 . Introduction 361 



2. The Absorption and Transport of Cholesterol and of Other Sterols. . . 362 



(1) Factors Altering Cholesterol Absorption 363 



(2) The Absorption of Sterols Other Than Cholesterol 365 



(3) The Transport of Cholesterol and of Other Sterols 368 



3. Changes of Sterols in the Gastrointestinal Tract 369 



4. Cholesterol in the Blood 370 



(1) The Nature of Cholesterol in the Blood 370 



(2) Physiologic Factors Altering Blood Cholesterol 371 



(3) Pathologic Factors Altering Blood Cholesterol 375 



5. The Biosynthesis of Cholesterol 377 



(1) Evidence Proving Cholesterol Sj^nthesis 377 



a. The Innbility of Insects to Synthesize Cholesterol 378 



(2) Acetate as a Source of Cholesterol 380 



(3) Primary Products Other Than Acetate \Miich Aie Sources of 



Cholesterol 382 



a. Ethanol 382 



b. Acetone 382 



c. Acetoacetate 383 



