Some favorable effects from the alimentary administration of insulin.

Abstract

Since July, 1922, when absorption of insulin from the alimentary tract was first observed by us, various attempts have been made to devise a practicable method for oral administration. No difficulty was experienced in demonstrating absorption of simple extracts by depancreatized dogs proving that insulin can survive the destructive action of the stomach. With normal animals, normal human subjects and diabetic patients having an efficient supply of trypsin the insulin was almost always destroyed., Nevertheless a few instances of obvious absorption were encountered in human diabetics. These were reported in brief at the 11th International Congress of Physiologists at Edinburgh, July, 1923. In this same month attempts were made to delay the destructive action of trypsin by combining with insulin certain weak organic acids and enclosing the combination in enteric coated capsules. Later enteric coated tablets were prepared for us by reputable pharmaceutical houses. Several cases have now been treated for different lengths of time with these tablets. Not all reacted favorably. Two of those giving the best reactions are shown in the table together with several additional tests by duodenal administration not previously reported. In all of the four cases reported the patients were on constant diets. The results show : (1) that insulin contained in 0.1 or 0.2 per cent HCl is absorbed from the human intestine; (2) that addition of alcohol to 5 to 8 per cent increases the absorption somewhat; (3) that alcohol alone, however, produces a drop in blood sugar but only a slight effect on the 24 hour elimination of sugar by the kidney; (4) that insulin combined with a weak organic acid or acid salt, the whole contained in an enteric coating which survives the stomach for at least three hours, can be absorbed in sufficient amount to lower blood sugar and urine sugar very materially.