In vitro intestinal processing of prostaglandin F2 alpha in rats: developmental aspects

Cytoprotective prostaglandins (PGs) such as PGF2 alpha are present in milk and can be absorbed intact from the gastrointestinal tract. Developmental differences in gastrointestinal PG metabolism in vivo have been previously reported. To evaluate the role of small intestinal tissue, detailed analysis of PG processing in vitro of small intestinal segments of suckling and weanling rats using everted sacs was performed. Sacs were incubated in Krebs-Ringer bicarbonate buffer, pH 7.4, at 37 degrees C. Bathing mucosal fluid contained [3H]PGF2 alpha. Proximal and middle intestinal segment everted sacs of suckling rats exhibited greater transfer of radioactivity in comparison with those of weanling rats. Whereas in suckling rats transfer of radioactivity decreased from proximal to distal regions of the intestine, no segmental differences were seen in weanlings. Maturational differences were also present in the capacity for PG catabolism. Suckling rat everted sacs had a greater proportion of radioactivity present as intact, unmetabolized PGF2 alpha present in sac tissue and serosal fluid in all intestinal segments in comparison with those of weanling rats. Weanling everted sacs contained greater amounts of less polar metabolites. These results indicate that there are quantitative and qualitative age-related differences in transfer and processing of exogenous PGF2 alpha in small intestinal tissue of developing rats.