Circulating immunoreactivities of gastrin, glucagon and VIP after jejuno-ileal bypass

Seven Sprague-Dawley rats (404-440 g) underwent a 90% jejuno-ileal bypass (JIB); the functional loop consisted of 1/3 ileum and 2/3 jejunum with the bypassed loop being anastomosed to the ascending colon. Seven control rats were sham-operated. After 35 days, the rats were fasted 18 hours and venous blood was collected. Immunoreactivity of gastrin, measured with an antibody binding equally to G17 and G34, was higher in the plasma of the JIB (256 +/- 55 SEM pg/ml) than control (85 +/- 9 pg/ml) rats. This agrees with recent human studies but is in conflict with results in less mature rats. VIP levels were not significantly different. Glucagon-like immunoreactivity measured with antibodies specific for the C- and N-terminal regions of the hormone, respectively, were also higher in the JIB (510 +/- 40 and 129 +/- 15 pg/ml) rats.