The effect of atropine on the insulin release caused by oral and intravenous glucose in human subjects.

Oral and intravenous glucose tolerance tests were performed on normal fasting subjects, with and without atropine. Insulin release after oral glucose was significantly diminished by atropine, and this effect could not be ascribed to the drug delaying glucose absorption. However, insulin release brought about by intravenous glucose was not altered by atropine. Possible interpretations of these results are discussed.