Actinomycin D suppresses hydrocortisone-induced changes in distribution and sialylation of brush-border enzymes in jejunal villi and crypts.

To investigate the regulatory role of hydrocortisone in the postnatal decline of sialylation of intestinal brush-border hydrolases, we applied actinomycin D, the well-known inhibitor of transcription, simultaneously with the hormone to 9-day-old rats. On day 12 actinomycin D inhibited hydrocortisone-induced changes in the profile of enzyme activities along the villus-crypt axis and suppressed the appearance of asialylated forms of enzymes manifested precociously in the differentiating crypt cells under the effect of the hormone. These findings were correlative with sialyltransferase activity along the villus-crypt axis.