Cephalic insulin response as a test for completeness of vagotomy to the pancreas

Rats received one of four surgical manipulations of the abdominal vagus; either a total vagotomy, a selective dorsal trunk vagotomy, a selective ventral trunk vagotomy or a sham operation. After recovery from the surgery, all rats were fasted overnight and given a saccharine solution the next day. Blood samples were taken 30 min prior to and 3 min after the sampling of the saccharin. Rats with the dorsal vagal trunk intact (those with either a sham lesion or with a selective ventral trunk lesion) had an elevation of immunoreactive insulin after drinking the saccharin whereas those with the dorsal vagal trunk severed did not. This simple procedure is recommended as a test for completeness of vagotomy to the pancreas since it is quick and easy to perform and since it is non-terminal and relatively non-invasive.