Reduced postheparin plasma diamine oxidase activity in patients with chronic renal failure.
The intestinal mucosa plays a fundamental role as the site for absorption of nutrients, and as an important barrier against potentially harmful agents in the gastrointestinal lumen. The functional integrity of the small bowel in patients with chronic renal failure was measured by post-heparin-diaminoxidase (DAO) activity in a low and safe dose of heparin (5000 IU) in patients with chronic renal failure participating in a hemodialysis program. The results of the study provide one of the first observations about a diminished DAO-response in patients with chronic renal failure reflecting a mucosal abnormality in these patients which has to be further characterized. Our findings also show that this reduced DAO activity is not caused by the effect of uremic toxins. These results further show that a smaller and safer i.v. dose of heparin (5000 IU or less) will release DAO activity as reliably as high doses used by others. We therefore conclude that postheparin DAO activity might be used as a new noninvasive test reflecting intestinal function in patients with chronic renal failure.