Gastrointestinal Distribution of Glucuronide Synthesis and the Relevant Enzymes in the Rat

Abstract

The rate of o-aminophenol glucuronide synthesis in the small intestine of the rat was found to decrease when going from the oral to the aboral end, where it was 15 per cent of the duodenal level. In the glandular stomach, caecum, and colon, the activity was 34, 15 and 30 per cent, respectively, of the duodenal value. The decrease in UDP glucuronyltransferase (p-nitrophenol) activity in the mucosal extracts was almost linear and amounted to 66 per cent from the oral to the aboral end of the small intestine. In the glandular stomach, caecum, and colon, the activities were 63, 32, and 83 per cent respectively, of the duodenal value. The β-glucuronidase activity increased linearly by 41 per cent when going from the oral to the aboral end of the small intestine. In the glandular stomach, caecum, and colon, activities of 82, 221, and 162 per cent respectively of the duodenal ones were observed.

These results indicate that the distribution pattern of glucuronide synthesis, observed in tissue slices, and the UDP glucuronyltransferase and β-glucuronidase activities in the extracts differ. This points to additional limiting factors in intact cells.

Key-words:

• intestine, small
• stomach colon
• gastrointestinal mucosa
• enzyme tests