Effect of hormone administration on the sialylation and fucosylation of intestinal microvillus membranes of suckling rats.

Cortisone, thyroxine, epidermal growth factor, or insulin were administered to 8-day-old rats for 4 days. In comparison to saline-injected controls, cortisone treatment: 1) lowered the sialic acid and raised the fucose content of the intestinal microvillus membranes, 2) increased [3H]fucose incorporation into these membranes, and 3) decreased the membrane binding of 125I-wheat germ agglutinin, while increasing the binding of 125I-ulex europeus agglutinin I and 125I-peanut agglutinin. Thyroxine treatment had similar effects on fucose content and 125I-ulex europeus agglutinin I binding, but did not alter [3H] fucose incorporation or sialic acid content. At the doses used, epidermal growth factor and insulin had no significant effects. The effect of cortisone treatment on sialic acid and fucose was commensurate with a 5- to 6-day acceleration of postnatal intestinal maturation. The changes in lectin binding, however, suggested qualitative differences between developmental and cortisone-induced membrane glycosylation. In addition, this study demonstrates significant quantitative and qualitative differences in the response of intestinal glycosylation to pharmacologic doses of the four hormones.