132 II. DIGESTION AND ABSORPTION OF FATS 



sample is taken for chylomicron count before the fat meal is started. The 

 fat is then administered with practically fat-free food such as bread, cereal, 

 or especially with boiled rice. The dose of fat which was found to be the 

 most satisfactory for adult human subjects was 20 g. ; when larger amounts 

 of fat were given, the chylomicron count was so high at the height of di- 

 gestion and absorption that an accurate estimation of their number was 

 quite difficult. Finger blood is usually employed in tests on human sub- 

 jects, while ear blood from large animals and tail blood from the rat are 

 satisfactory. In addition to the fasting sample, blood samples are with- 

 drawn at intervals of one hour or less until the chylomicron count has re- 

 turned to the preprandial level. This usually requires eight to ten hours. 

 For the counting of the chylomicrons, a high-power dark-field microscope 

 is employed, with homogeneous oil between the top of the condenser and 

 the under surface of the slide, as well as upon the top of the cover glass. 

 The slide contains a micrometer net in half-millimeters, the entire net 

 containing 15 small squares. The usual practice is to count the chylo- 

 microns in all 15 squares in five different areas. The results for a sample 

 experiment are shown in Figure 13. 



Irwin, Steenbock, and Templin 611 employed the Gage-Fish procedure 

 for the study of the rate of absorption of fats after feeding 0.5 ml. of the 

 product under investigation to fasted rats. Tail blood was used. How- 

 ever, these authors reported that this method "had little quantitative 

 value." Frazer and Stewart, 621 - 622 using a carefully standardized technic, 

 were able to demonstrate that the neutral fat content of the blood runs 

 parallel to that of the chylomicrograph, whereas blood cholesterol yields a 

 value quite divergent from it. The timing of the basic levels and peaks of 

 the chylomicrons and neutral fat content coincides exactly. Frazer 623 

 states, however, that "the changes demonstrated by this method are suffi- 

 ciently great to be significant, but the quantitative relationships can only 

 be regarded as relative at present." Cooper and Lusk 624 reported that the 

 chylomicron count is a reliable index of blood lipids. More recently, 

 Nhavi and Patwardhan 625 used the chylomicron procedure with some 

 success in studying the absorption of fats in human subjects. 



c. Hemolipokrit Method. Riickert 626 has developed a procedure based 

 on the analysis of the fat in the serum from 3 ml. samples of blood by a 



621 A. C. Frazer and H. C. Stewart, /. Physiol, 90, 18-30 (1937). 



822 A. C. Frazer and H. C. Stewart, /. Physiol, 95, 21P-23P (1939). 



823 A. C. Frazer, Physiol Revs., 20, 561-581 (1940). 



624 R. R. Cooper and H. Lusk, Am. J. Digestive Diseases, 9, 395-396 (1942). 



626 N. G. Nhavi and V. N. Patwardhan, Indian J. Med. Research, 34, 49-58 (1946). 



626 W. Riickert, Klin. Wochschr., 10, 1853-1858 (1931). 



