Measurement of sialyl-transferase activity in isolated colonic mucosal cells of the rat

Abstract

An assay for sialyl-transferase activity in isolated rat colonic mucosal cells has been developed. Total and specific activity with asialobovine sub-mandibular gland glycoprotein and endogenous substrates was approximately twofold higher in the proximal, relative to the distal, colon. These activities were similar when asialo-a-acid glycoprotein was used as substrate. Endogenous activity was approximately 10-fold lower than with exogenous substrates in both proximal and distal colonic segments. Analysis of total and specific sialyltransferase activity up to 7 weeks after jejunoileal bypass (JIB) and sham operation showed a marked increase at the first week, decreasing towards normal by week 7. Similar differences between proximal and distal colon, and with the type of substrate, were found with both groups of operated animals. Histochemical analysis showed small elevations after 1 week for sialo and sulphomucins after the JIB operation only.