[Plasma activity of diamine oxidase after heparin in patients with diabetic enteropathy]

Diamine oxidase (DAO) is an enzyme found almost exclusively in the enterocyte of the villous tips. In the basal state plasma DAO activity is low but increases significantly after i.v. injection of heparin. It is well recognised that postheparin plasma activity of DAO reflects clearly the integrity of the small bowel mucosa. The aim of this study was to investigate postheparin plasma DAO activity in diabetics with enteropathy. The study was carried out in a group of 72 individuals subdivided into five groups. Group I consisting of 16 patients with type 1 diabetes, group II--20 patients with type 2 diabetes, group III--8 patients with newly diagnosed type 1 diabetes, group IV--8 diabetics with enteropathy and group V--the control group. Blood samples were taken at the time 0' and at 60' and 120' intervals following i.v. injection of heparin. DAO activity was assessed by RIA methods. Basal values of DAO were nearly the same in all of the subjects (< 50 pmol/min/ml). After injection of heparin a very high DAO activity was observed in all groups (> 400 pmol/min/ml) except group IV (< 270 pmol/min/ml) (p < 0.001). There were no significant differences between the groups according to the type of diabetes, its duration and the methods of treatment. In conclusion, the postheparin plasma DAO activity in diabetics with enteropathy was very low, but of itself, diabetes and its treatments had no effect on the results under investigation.