5 6 2 



MECHANISM OF BILE SECRETION. 



In cases of occluded gall bladder this mucm-like substance has been 

 found to be the chief organic solid of the secretion. 1 



Mayo Robsoris Analysis. 



Organic matter, chiefly muciri . . . '672 per cent. 



Chlorides equal to NaCl . . . . '573 ,, 



Sodium carbonate ..... '220 

 Other salts containing phosphates, potassium 



salts, etc . -071 



The fact that the amount of this substance does not vary with the 

 true bile constituents either at different periods of the day, 2 or in febrile 

 conditions, 3 indicates very clearly that it is not formed by the liver 

 cells. 



Salts of the bile acids. These are entirely produced in the liver 

 cells. In Birch and Spong's case, and in the case examined by Mayo 

 Eobson, they were entirely absent from the secretion of the gall 

 bladder. 



That they are actually formed by the liver cells, and not merely ex- 

 tracted from the blood, was demonstrated by Minkowski and Naunyn. 4 

 These observers found that, while bile salts are normally absent from the 

 blood, they appear when the bile duct is ligatured. If, however, the 

 liver be excluded from the circulation, there is no accumulation of bile 

 salts in the blood. 



The source of the cholalic acid moiety of the glycocholic and 

 taurocholic acids is unknown. The source of the glycine and taurine is 

 to be sought ultimately in the proteids of the body and of the food, 

 since these alone can yield the nitrogen and sulphur. Both are amido- 

 acids of the fatty acid series. 



Nencki, Pawlow and Zaleski, 5 have shown that the surplus proteid 

 of the diet is largely broken down into ammonia compounds in the wall 

 of the intestine, and these compounds pass to the liver. Yon Schroder 6 

 demonstrated that ammonia compounds are readily converted to urea by 

 the liver. Hence by far the greater quantity of nitrogen in excess of 

 that required must undergo this transformation, and it is not to be 

 expected that an additional quantity of proteids in the food will lead to 

 a markedly increased formation of bile acids. Spiro, 7 by feeding animals 

 with biliary fistulse upon various kinds of food, found that a proteid diet 

 increased the nitrogen and sulphur excreted in the bile, but not in 

 proportion to the amount of proteid taken. 



The following figures illustrate Spiro's results : 



1 Hoppe-Seyler, " Physiol. Chem.," S. 302. 



2 Eep. Lab. Roy. Coll. Phys., Edinburgh, vol. iii. p. 204. 



3 Ibid. p. 212. 4 Arch.f. exper. Path. u. PharmakoL, Leipzig, Bd. xxi. S. 7. 

 5 Ibid., Bd. xxxvi. S. 26. 



G Ztsehr. f. physlol. Chem., Strassburg, Bd. ii. S. 234. 

 7 Arch.f. Physiol., Leipzig, 1880, Supp. Bd. S. 50. 



