458 V. BLOOD LIPIDS 



MacLachlan 661 was unable to change the serum lipid in cats or dogs by 

 exposure to low atmospheric pressures for periods of three to six hours. 

 No consistent changes could be demonstrated in the plasma of human beings 

 who had remained for several days at the reduced pressures encountered 

 at elevations of 10,000 to 14,000 feet. 662 Another suggestion as to the 

 reason for the increase in lipid in anemia is that advanced by Fishberg, 649 

 who suggested that the lipid can compensate for the loss of blood proteins 

 by aiding in the adjustment of the colloid osmotic pressure in the blood. 



Variations in the pattern of blood lipids occur in different types of ane- 

 mia. Thus, in the erythroblastic anemia of children, the blood cells 

 were shown to contain increased amounts of neutral fats. 654 A greater 

 proportion of esterified cholesterol was observed in sickle-cell anemia, 654 

 whereas, in pernicious anemia, the erythrocytes contain more than the nor- 

 mal amount of cholesterol esters, and an abnormally low proportion of phos- 

 pholipid. 658 The ether-insoluble phospholipids are increased when pernicious 

 anemia is treated with liver extracts. 663 



h. The Blood Lipids in Diseases of the Gastrointestinal Tract. Any 

 condition which retards the absorption of fats from the gastrointestinal 

 tract will alter the normal curve for alimentary lipemia. This will occur 

 when fat absorption is depressed, due to faulty secretion of pancreatic 

 juice or of bile, and to a lesser extent of gastric juice. 



Any obstruction of the gastrointestinal tract will cause vomiting, with 

 a ketosis followed by a hyperlipemia. However, as this condition is pro- 

 longed, the level of blood lipids falls to subnormal values. 533 When the 

 foodstuffs are delayed in the stomach for a prolonged period, due to the 

 failure of this organ to empty, the alimentary lipemia is delayed. 664 



In cases of pancreatic steatorrhea, in which pancreatic juice is excluded 

 from the lumen of the intestine, considerable amounts of lipid escape 

 absorption, and are excreted in the feces. This circumstance explains why 

 the alimentary lipemic reaction is decreased or completely abolished in 

 pancreatic steatorrhea. 665 Furthermore, in other types of steatorrhea 

 and allied conditions (non-pancreatic steatorrhea, celiac disease, tropical 

 and non-tropical sprue), there is a decrease in fat absorption. In all these 

 conditions, the hyperlipemia following the ingestion of fat is reduced or 

 entirely eliminated. 666 ~ 670 It has been suggested 202 that the postabsorptive 

 concentrations of lipid phosphorus and cholesterol are usually reduced in 

 patients suffering from steatorrhea. 



661 P. L. MacLachlan, J. Biol. Chem., 129, 465-469 (1939). 



662 G. L. Muller and J. H. Talbott, Arch. Internal Med., 47, 855-860 (1931). 



663 E. Kirk, Am. J. Med. Sci., 196, 648-654 (1938). 



664 B. Hejda, Am. J. Med. Sci., 180, 84-90 (1930). 



