The effect of the route of delivery of urogastrone on intestinal regeneration.

Urogastrone (UG) administered subcutaneously increases the rate of intestinal regeneration (neomucosal growth) on patched intestinal defects. Our purpose was to determine the optimal route of delivery of UG for intestinal regeneration. In 22 New Zealand white rabbits (2.1 to 3.4 kg) 2 X 5 cm ileal defects were patched with adjacent cecal serosal surface. Group I (n = 6) served as controls. Group II (n = 5), group III (n = 6), and group IV (n = 5) received UG, 1.5 micrograms/kg/hr, intravenously, subcutaneously, and intraluminally via miniosmotic pumps. Neomucosal growth was assessed 7 days after patching. Serum UG levels were detectable in only the intravenous group. Coverage of the patched defect and neomucosal area was significantly greater and contraction of the defect less in the groups receiving UG (p less than 0.05). Neomucosal area was highest in the intravenous group (286 +/- 16 mm2), intermediate in groups III and IV (236 +/- 19 and 215 +/- 20 mm2), and lowest in the control group (152 +/- 17 mm2; p less than 0.05). Sucrase and maltase activities were significantly higher in the intravenous group. Crypt cell production rate and ornithine decarboxylase activity were greater in the UG-treated animals. UG stimulated intestinal regeneration by all routes of delivery. The intravenous route had the greatest effect and was associated with the highest serum levels of UG. These findings have implications for the mechanism of the trophic effect of UG on the intestinal epithelium.