Small bowel adaptation after intestinal resection in guinea pig with functional adaptation of vitamin B 12 absorption.

Abstract

Although intestinal adaptation has been well-documented in the rat, the phenomenon has not been described in guinea pigs. The morphologic response of the ileum was therefore examined in female jejunectomized guinea pigs. Cellular hyperplasia was demonstrated by a twofold increase in villous height and DNA content per unit length of ileum 8 weeks after resection. A functional response to jejunectomy was confirmed by the significantly greater than normal absorption of a 50-ng oral dose of vitamin B12 (cyanocobalamin58Co) 5 weeks after resection. Attachment of cyanocobalamin57Co to the ileal mucosa was increased 8 weeks after operation, but uptake per milligram of mucosal DNA was decreased. The results indicate that ileal adaptation occurs after proximal resection in guinea pigs and that there is an associated increase in the capacity to absorb vitamin B12.