Influence of somatostatin and bombesin on plasma enteroglucagon and cell proliferation after intestinal resection in the rat.

The possible relationship between enteroglucagon and cellular proliferation in a rat model of intestinal adaptation after suppression and stimulation of enteroglucagon by somatostatin and bombesin has been investigated. Forty eight rats were divided into three groups of 16 animals, each group being further sub-divided into eight animals having intestinal resection and eight having intestinal transection. Group 1 was given somatostatin to suppress enteroglucagon, group 2 was given bombesin to stimulate enteroglucagon and group 3 (control group) had neither peptide. All animals were killed 12 days after operation. Circulating enteroglucagon and crypt cell production rate (CCPR) in the terminal ileum were measured. After administration of somatostatin (group 1) both CCPR and plasma enteroglucagon were lower after resection than controls (group 3) (p less than 0.001). Transected rats receiving somatostatin showed a reduction in both plasma enteroglucagon and CCPR, but only the fall in enteroglucagon was statistically significant (p less than 0.001). Transected rats receiving bombesin (group 2) had raised plasma enteroglucagon and CCPR compared with the control group (group 3) (P less than 0.005) but there was no significant further rise in these already raised parameters in resected animals. This study indicates that cell proliferation in the rat small bowel after surgery can be influenced by regulatory peptides. The changes in enteroglucagon corresponded closely with changes in CCPR, and this peptide remains a favoured candidate for the humorally mediated trophic influence on the small bowel.