Intestinal resection in the neonatal rat: stimulus for precocious intestinal maturation

To investigate whether intestinal resection accelerates mucosal maturation in suckling rats, macromolecular absorption, sucrase and lactase activity, RNA/DNA ratios, and intestinal morphology were determined 5 days after partial small intestinal resection or intestinal transection in 15-day-old rats. Villous height and crypt depth, lactase and sucrase activity, and RNA/DNA ratios were significantly increased in remaining intestine in animals that underwent surgery. These animals, together with normal control animals, were also gavaged with 100 mg bovine serum albumin, and serum levels were determined after 2.5 h. Mean serum levels of bovine serum albumin were 0.135 +/- 0.034 micrograms/ml/cm of residual intestine after transsection, 0.257 +/- 0.078 micrograms/ml/cm after resection, and 0.404 +/- 0.030 micrograms/ml/cm in controls. These studies demonstrate that intestinal resection during the suckling period of the infant rat results in several morphologic and physiologic changes that resemble precocious maturation of the small intestine.