In Vitro Study on the Rate of Intestinal Absorption of Insulin

Abstract

Using an everted sac technique, the intestinal absorption of insulin in the rabbit has been investigated.
Insulin was shown to cross the intestinal wall, as demonstrated by the immunoreactive insulin inside the sacs (serosal fluid). The rate of insulin transference for a period of one hr was small, corresponding to approximately 0.1% of the insulin added to the mucosal fluid. This rate was not inhibited by the addition of 2, 4-dinitrophenol.
The small transference rate would indicate that the submucosal and muscular tissues of the intestinal wall, in the absence of vascular perfusion, present a barrier to the movement of large molecular weight substances.