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W. R. ELOOR 



]\[iink and Friedenthal that the fat content of the corpuscles increased 

 during fat absorption has been recently confirmed and it was also shown 

 that the increase of fat was accompanied by increases of lecithin, from 

 which the inference was drawn that the corpuscles take up the suspended 

 fat from the plasma and transform it into lecithin. Some support is 

 given to this inference by the observations of Thiele and of Foa (1015), 

 who found that the blood estera.se decomposes lecithin only when corpuscles 

 are present, indicating that this esterase, which presumably also synthesizes 

 lecithin, is present only in the corpuscles. On the other hand, later work 

 in this laboratory has shown that in certain dogs lecithin does not markedly 

 increase in the corpuscles but does in the plasma. As has been recently 

 pointed out by Hang (1018), animals show great individuality in their 

 blood reaction to ingested fat. Some can dispose of large amounts without 

 showing much effect on the blood lipoids; others react strongly. He 

 makes some suggestions to explain the differences habituation to fat food 

 and the presence of carbohydrate in the food or of much stored glycogen 

 being in his opinion important factors. As regards lecithin formation in 

 the blood it is not likely that it is confined to the corpuscles but probable 

 that other cells with which the suspended fat comes in contact have the 

 same function. Furthermore, the failure to find increased lecithin values 

 in the corpuscles of certain animals does not necessarily mean that it is 

 not formed there. It may be formed and pass at once into the plasma. 



Lipoids of the Blood. A great deal of investigative work has been 

 done on the lipoids of the blood both in the normal and in various path- 

 ological conditions, the results of which in general bear out the rule just- 

 enunciated, that when one of the constituents (fat, cholesterol, lecithin), 

 is found abnormal the other two will also be abnormal and in the same 

 direction. It has been shown how feeding fat increases the blood lecithin, 

 and while there is some question as to whether blood cholesterol is in- 

 creased in the lipemia produced by a single fat feeding there is none at all 

 where the lipemia persists. Feeding cholesterol produces not only increase 

 of blood cholesterol but also of blood lecithin. Whether feeding lecithin 

 would produce increases in the other two constituents has not been reported 

 and probably cannot be determined since lecithin is largely hydrolyzed 

 in the alimentary tract and probably absorbed as fat although some may 

 appear as such in the chyle. While there are not enough data available 

 to justify the statement that there is a constant relation between the 

 three -constituents in normal and in most pathological conditions, the 

 tendency seems to be in that direction and, at any rate, it appears reason- 

 ably certain that the three substances are interdependent, and also that all 

 are concerned in the metabolism of the fatty acids. 



The concentration of fat, cholesterol and lecithin in the blood is fairly 

 constant for the same species but varies greatly in different species, the 

 variation being noticeable mainly in the plasma, The concentration in 



