21 
ON THE SYNTHESIS OF FATS ACCOMPANYING 
ABSORPTION FROM THE INTESTINE, AND ON 
THE LIMITATIONS OF SYNTHESIS BY ENZYMES 
AND BY LIVING CELLS, RESPECTIVELY 
By BENJAMIN MOORE, M.A., D.Sc. 
JOHNSTON PROFESSOR OF BIO-CHEMISTRY AT UNIVERSITY COLLEGE, LIVERPOOL 
IT is now generally accepted that the neutral fats of the food are completely split 
up in the course of intestinal digestion, by the lipase of the pancreative juice, 
into free fatty acids and glycerine, and that the fatty acids are then rendered 
soluble by the bile salts and lecithin, either in the form of free acids or as alkaline 
soaps. So that all the constituents formed in fat digestion are finally taken up by the 
columnar cells in soluble form.' 
It has long been known that the main part, if not all, of the absorbed fat 
leaves the intestinal wall by the channel of the lacteals, and that the fatty chyle 
contained in these vessels, after traversing the abdominal lymphatic glands, is poured 
by the thoracic duct into the systemic circulation. Now somewhere along this 
course a synthesis occurs of the fatty constituents back again into neutral fats, for 
Munk 1 has shown that when fatty acid, instead of neutral fat, is administered by the 
mouth, a synthesis has been effected by the time the absorbed fatty acid has entered 
the thoracic duct, whereby from 90 to 95 per cent, of the free acid has been combined 
to form neutral fat. It is also worth noting, in view of the discussion which will be 
presented later on in this paper of the character of the synthesis here brought about, 
that it is unnecessary to feed glycerine along with the fatty acid ; that is to say, 
somewhere between intestine and thoracic duct, glycerine is either carried in or 
synthetically formed from other constituents, and united to the fatty acid to form 
neutral fat. This experiment, therefore, casts doubt on the view that the fatty acid 
in the normal course of digestion of fat is entirely re-united to the same glycerine 
from which it was detached in the intestine. For it is probable that the rates of 
absorption of glycerine, and fatty acid or soap, respectively, from the intestine are not 
quite identical ; and although it is possible that these constituents after absorption are 
stored by cells somewhere along the channel of absorption, and re-united to each 
1 . Moore & Rockwood, Proc. Roy. Soc, vol. lx, 1897, p. 438 ; Journal of P/iysio/og y, vol. xxi, 1 897, p. 58 ; Moore & Parker, 
Proc. Roy. Soc, vol. lxviii, 1901, p. 64; Pfliiger, Arch, f, d. gcs. Physiologic, Bd. lxxxii, 1900, S. 303, 381; BH. lxxxv, 1901, 
S. 1 ; Bd. lxxxviii, 1902, p. 299, 431 ; Bd. xc, 1902, S. I. 
2. Virchotvs Arch., lxxx, 1880, S. 17 ; xcv, 1884, S. 452. 
