The absorption of n-hexadecane from the alimentary tract of the cat.

IN continuance of previous studies of factors affecting the nature and amount of the unsaponifiable fractions of liver, it was shown that n-hexadecane is absorbed from the alimentary tract of the rat to the extent of 50 to 108 mg. daily, depending on the quantity of hydrocarbon included in the diet [Mahdi and Channon, 1933]. This result is of interest in relation to fat absorption, because it is opposed to current ideas that absorption of paraffinoid substances does not occur. A point of further importance arose in the course of this work. In one experiment, of 149 g. of hexadecane administered, only 116 g. were excreted, and of the 33 g. of hexadecane unaccounted for no more than an insignificant trace, if any, was present in the liver, whilst the unsaponifiable fraction of the carcass contained at most 1-85 g. of the hydrocarbon. The suggestion contained in this result of the ability of the rat to metabolise a normal hydrocarbon together with the surprising fact that the hydrocarbon failed to appear in the liver but did apparently find its way to the tissues, led us to investigate the matter further. Our first object was to confirm and extend these results by use ofan animal which would provide more material for investigation, and also to study the distribution ofthe hydrocarbon in the tissues by its isolation in chemically pure form. EXPERIMENTAL.