FACTORS ALTERING CONCENTRATION OF BLOOD LIPIDS 411 



particles when the pH of the solution approached the isoelectric point of 

 the protein. Thus, a coalescence of the particles was observed when the 

 acidity was sufficient to precipitate the protein films. For a further dis- 

 cussion, see pages 426—150. 



(a) Immediate Effects of the Ingestion of Fat. a'. The Effect of the In- 

 gestion of Fat on Blood Fats and Fatty Acids: As early as 1877, Ahlfeld 338 

 demonstrated that the blood serum of a dog became milky, due to its in- 

 creased fat content, after a heavy fat meal was given. Subsequently, it 

 was shown that a hyperlipemia could readily be produced in car- 

 nivora, 223,224 ' 339 but not in herbivora. In most cases, attempts to produce 

 an alimentary lipemia in man have produced only slight effects, or have 

 even resulted negatively. 281,340 ~ 344 The marked variation between the 

 susceptibility of carnivora and of man to alimentary lipemia, after fat 

 ingestion, is believed to be partially explained by differences in the dosages 

 of fat employed. Recognizing this fact, Man and Gildea 345 carried out 

 tests, with normal adults, in which the fat dosage was fixed at 3.5 g. per 

 kilogram body weight. By means of this experimental procedure, these 

 workers were able to demonstrate a marked alimentary lipemia in man. 

 On the other hand, when the dosage was reduced to 0.5 g. per kilogram 

 body weight, only minor changes in the levels of blood lipids were noted, 

 and the results were quite inconstant. 



After the ingestion of a large dose of fats, there is a gradual increase in 

 blood lipids; the serum lipids may remain elevated for six hours or longer, 

 depending upon the quantity of fat given. The maximum level may not 

 be reached until as late as the sixth hour. The fat tolerance curve ob- 

 tained after a test meal of fat stands in sharp contrast to the glucose tol- 

 erance curve, not only in respect to the slow rate of development, and the 

 prolonged period required to reach the maximum, but also as regards the 

 prolonged decay curve. 



On the basis of experiments on dogs, Bang 346 reported differences in the 

 hyperlipemia produced by various fats. Thus, lard did not cause any 

 increase in blood lipids, but butter and olive oil elicited a considerable 



338 F. Ahlfeld, Centr. Gyndkol, 1, 265-267 (1877). 



339 K. Reicher, Verhandl. deut. Kongr. inn. Med., 28, 327-330 (1911). 



340 A. Hiller, G. C. Linder, C. Lundsgaard, and D. D. Van Slyke, J. Exptl. Med., 

 39, 931-955 (1924). 



341 I. L. Chaikoff, T. H. McGavack, and A. Kaplan, J. Clin. Invest., 13, 1-13 (1934). 



342 J. A. Gardner and H. Gainsborough, Biochem. J., 22, 1048-1056 (1928). 



343 I. H. Page, L. Pasternak, and M. L. Burt, Biochem. Z., 223, 445-456 (1930). 



344 H. R. Rony and A. J. Levy, J. Lab. Clin. Med., 15, 221-228 (1929-1930). 



345 E. B. Man and E. F. Gildea, J. Biol. Chem., 99, 61-69 (1932-1933). 

 346 1. Bang, Biochem. Z., 91, 111-121 (1918). 



