Passage of Insulin through the Wall of the Gastro-intestinal Tract of the Infant Mouse

Abstract

Mosinger, Placer and Koldovsky¹, in a recent communication, have shown that insulin administered orally to suckling rats 2 and 8 days old causes a large drop in blood-sugar levels, but does not do so in 21- and 30-day old rats. Previously I had found that the gut of the 8-day old mouse is permeable to insulin but that this permeability declines thereafter. This work was quoted by Halliday² and, although Mosinger et al. refer to that paper, they do not mention my findings.