426 V. BLOOD LIPIDS 



sterol in both the plasma and the corpuscles following exertion. On the 

 other hand, Patterson 420 observed increases in blood fat of as much as 40% 

 after exercise, although this increase could be prevented if sugar was given. 

 However, Patterson, 420 Rakestraw, 421 and Cattoretti 422 reported that the 

 blood cholesterol remains unchanged after strenuous exercise. Tanner 423 

 found a mean value for serum cholesterol in forty-six young men of 190.5 ± 

 28.5 milligram per cent. A statistically significant correlation was found 

 to exist between serum cholesterol and subscapular subcutaneous tissue, 

 as well as between the cholesterol and the endomorphic component of 

 physique. The effect of exercise on ketosis is discussed later (see Volume 

 III). 



(6) Specific Compounds that Affect Alimentary Lipemia 



a. The Effect of Heparin, (a) Heparin as an Anticoagulant. Heparin 

 is a substance originally isolated from liver, in 1918, by Howell and Holt, 424 

 who recognized that it possesses an anticoagulating action in blood. It 

 was subsequently further purified by Howell, 425 and by Charles and Scott, 426 

 who also found that beef lung was superior to beef liver as a source of the 

 product. 427 It is now known that the heparin molecule contains a hex- 

 uronic acid (presumably glucuronic acid), glucosamine, esterified sulfuric 

 acid groups, and acetylated amino groups. 428-432 This composition would 

 suggest that heparin should be classified as a chondroitin sulfuric acid. 

 The anticoagulant properties are presumably referable to the presence of 

 sulfuric acid in the molecule. According to Charles and Scott, 427 heparin 

 is widely distributed in tissues ; these workers cite the following concentra- 

 tion on the substance (expressed in Howell units per kilogram of tissue) : 

 dog liver, 4400; beef liver, 1900; hog liver, 1700; beef lung, 2200; beef 

 muscle, 1900; beef heart, 380; and beef blood, 60. 



(6) Heparin as a Clearing Agent. The ability of heparin to cause rapid 



420 J. W. T. Patterson, Biochem. J., 21, 958-966 (1927). 



421 N. W. Rakestraw, J. Biol. Chem., 47, 565-591 (1921). 



422 F. Cattoretti, Arch. ital. biol, 63, 113-121 (1915). 



423 J. M. Tanner, J. Physiol., 115, 371-390 (1951). 



424 W. H. Howell and E. Holt, Am. J. Physiol, 47, 328-341 (1918). 

 426 W. H. Howell, Am. J. Physiol, 63, 434-435 (1923). 



426 A. F. Charles and D. A. Scott, /. Biol Chem., 102, 425-42$ (1933). 



427 A. F. Charles and D. A. Scott, J. Biol. Chem., 102, 431-435 (1933). 



428 W. H. Howell, Bull Johns Hopkins Hosp., 42, 199-206 (1928). 



429 A. F. Charles and D. A. Scott, Biochem. J., SO, 1927-1933 (1936). 



430 A. F. Charles and A. R. Todd, Biochem. J., 34, 112-118 (1940). 



431 E. Jorpes, Biochem. J., 29, 1817-1830 (1935). 



432 E. Jorpes, Acta Med. Scand., 88, 427-433 (1936). 



