Activities of 11beta-hydroxysteroid dehydrogenase 2 in different regions of the intestinal tract of pigs.

11beta-Hydroxysteroid dehydrogenase 2 (11beta-HSD 2) converts active cortisol to inactive cortisone and thus modifies the availability of glucocorticoids for the target tissue. An additional function is the protection of the aldosterone receptor in mineralocorticoid-sensitive tissues such as the kidney and the gut. The occurrence of 11beta-HSD 2 activity was investigated in several species. Data for the pig, however, so far are missing. The activity was determined by a radio-enzyme-assay based on the conversion of tritiated cortisol to cortisone under standardized incubation conditions in supernatants of homogenates prepared from tissues of four castrates. Tissues comprised several locations along the intestinal tract and in addition kidney, lung, muscle, heart, spleen and pancreas. Highest values of the enzyme activity were found in kidney and very low activities in lung tissue but no activity in muscle, spleen, heart and pancreas. In the gut, there was a continuous increase in enzyme activity from the duodenum (0.60 pmol x min(- 1) x mg protein(- 1)) towards the colon with maximum values in the colon transversum (23.32 pmol x min(- 1) x mg protein(- 1)). In the colon the activity was 10-fold higher than in jejunum and 3-fold higher compared to ileum. The activities did not differ significantly between the colon transversum and colon descendens.