EXCRETION OF LIPIDS BY WAY OF LARGE INTESTINE 339 



resulted from the ingestion of large amounts of a cholesterol-low diet, 

 although the amounts of cholesterol eliminated were much less than were 

 those resulting from the administration of a cholesterol-rich diet. Actually, 

 the increased cholesterol excretion in dog bile after cholesterol-rich diets 

 comprised only a small proportion of that ingested. After feeding 5 or 

 6 g. of cholesterol in the form of eggs and brain, McMaster 586 could ac- 

 count for an increased bile cholesterol of only 60 mg. ; this amounted to 

 less than 2% of the ingested cholesterol. In fasting, the total excretion 

 of cholesterol in the bile was found to be largely suppressed, although the 

 concentration in this fluid was actually increased. 



The level of cholesterol in the bile has also been shown to be a function 

 of the endocrine glands. Thus, Rosenman, Friedman, and Byers 587 

 reported that the hyperthyroid rat excretes far more cholesterol in its 

 bile than does the normal rat. This result is in contradistinction to the 

 effect of hyperthyroidism on plasma cholesterol, in which case a hypo- 

 cholesterolemia is observed. 



In the case of man, consistent values of 0.045 to 0.055% for cholesterol 

 from bile obtained by gall-bladder drainage have been reported by 

 Nathan. 588 Increased blood cholesterol with a concomitant decrease in 

 bile cholesterol has been reported during pregnancy. 589 Salomon 590 

 found that the cholesterol content of human bile was increased by butter, 

 and by such high cholesterol-containing foods as eggs and brains. 591 ' 592 

 This is similar to the response noted earlier in dogs. 58fi Thus, in man, bile 

 contained 13 to 21 milligram per cent of cholesterol on a basal diet of pro- 

 tein. This level was increased to 25 to 35 milligram per cent when four 

 eggs were included in the dietary regimen; when 200 g. of butter were 

 added to the basal diet, the bile contained 38 to 76 milligram per cent of 

 cholesterol. It was later shown that the cholesterol level of the duodenal 

 contents was markedly lowered on a cholesterol-low diet consisting of 

 bananas, 591,592 although it is possible that the bile secretion may have 

 been less on such a dietary regimen. More recently, Riegel and co- 

 workers 593 failed to find a correlation between the amount of bile drained 

 externally from their human patients and the cholesterol content of the 

 bile; however, the concentration of bile salts and that of cholesterol were 

 found, in general, to run parallel. 



587 R. H. Rosenman, M. Friedman, and S. O. Byers, Science, 114, 210-211 (1951). 



588 M. Nathan, Arch. path. Anat. u. Physiol. (Virchow's), 228, 51-67 (1920). 



589 E. E. Pribram, Arch. Gynakol, 119, 57-68 (1923). 



590 H. Salomon, Arch. Verdauungskrankh., 89, 16-49 (1926). 



591 H. Salomon, Arch. Verdauungskrankh., 39, 325-334 (1926). 



592 II. Salomon and L. L. Silva, Arch. Verdauungskrankh., 36, 353-359 (1926). 



593 C. Riegel, I. S. Ravdin, and H. J. Rose, Am. J. Med. Sci., 193, 446-447 (1937). 



