The influence of oils and of lecithin on the protein metabolism

Abstract

Experiments intended to determine the influence of different quantities of vegetable oils, like olive oil, cotton-seed oil, and peanut oil, on the metabolic processes, when injected subcutaneously, have been performed on dogs and rabbits. One experiment on an otherwise fasting dog is presented herewith. The oil given in this case was cotton-seed oil put into the form of a very fine emulsion in 0.8 per cent. sodium chloride with 5 per cent. lecithin as emulsifier. The dog was kept in the Voit-Pettenkoffer respiration apparatus for about twenty-three hours out of the twenty-four, and the total metabolism was calculated from the total output of nitrogen and carbon. The dog developed a small abscess from one of the points of injection but there was no fever up to the time the experiment closed, hence we believe the figures given represent a true comparison between the effect of fat fed subcutaneously and the same quantity of the same fat given by mouth. On both food days it will be observed that the total energy production is higher than it is on the fasting days. What is more significant, perhaps, is the fact that this effect of the food to increase the metabolism (specific dynamic action) is relatively greater on the day when the fat was injected subcutaneously than when it was taken in the natural manner. The amount of the oil fed was about sufficient to cover the entire energy requirement of the dog and apparently it was all absorbed from the points of injection (axillæ and groins) into the circulation as completely as it was when absorbed through the alimentary canal.