Angiotensin-converting enzyme activity in stools of healthy subjects and patients with celiac disease

Abstract

Angiotensin-converting enzyme (ACE) is a dipeptidylcarboxypeptidase that occurs in three types of cells: endothelial, epithelial, and neuroepithelial. ACE activity is present in plasma, urine, and vascular endothelium. High levels of ACE are found in the brush border of human small bowel. The aim of this study was to evaluate ACE activity in human stools and to find a correlation with the intestinal loss of epithelial cells. Fifteen healthy subjects (HS) (8 males, 7 females; age range 6-56 years), 20 patients with celiac disease (CD) (11 males, 9 females; age range 15-53 years), and 18 patients with CD in remission after a gluten-free diet (CD-GFD) (8 males, 10 females; age range 14-54 years) were enrolled in the study. The fecal ACE activity was measured in all groups. Fecal samples were kept at -20 degrees C for a subsequent test. In HS, fecal ACE activity was 21.03 +/- 16.17 nmol/min/100 g (mean +/- SD). In patients with CD with subtotal mucosa atrophy, ACE activity was significantly higher (113 +/- 88.94) than in HS and CD on GFD (36.65 +/- 23.9). We have demonstrated ACE activity in human stools. ACE activity in stools seems to derive from the microvilli of the intestinal mucosa, thus suggesting the potential usefulness of ACE determination as an index of enterocyte damage.

Faecal proteomics: A tool to investigate dysbiosis and inflammation in patients with cystic fibrosis

“…In addition, angiotensin-converting enzyme (ACE) was detected more in patient samples. ACE is found in the brush border of the small intestine and detection of high amounts of ACE in stool is an indication of enterocyte damage [30].…”

Reduced Severity of a Mouse Colitis Model with Angiotensin Converting Enzyme Inhibition

“…However, we are unaware of any previous study examining the role of ACE in apoptosis in experimental colitis. Although it has been demonstrated that ACE is highly expressed in the small and large intestinal epithelium of rodents and of humans (26,29,49), the functional role of this expression is uncertain. It was interesting to note that we observed a marked increase in the expression of ACE protein in the placebo-treated DSS mice.…”

“…ACE is expressed at particularly high levels on pulmonary vascular endothelium, renal tubules, and the myocardium; but also -surprisingly -in both the colonic and small intestinal epithelium (26)(27)(28). In addition, ACE is shed from the gut epithelium and can be detected in stool (49). Although the hypertensive effects of Ang II are well known, the function of ACE in the small and large intestine is far less well understood.…”

ACE and ACE2 catalytic activity in the fecal content along the gut

“…Deddish et al described the presence of an active Ndomain ACE isoform in the ileal fluid of patients that underwent surgical colectomy 27 and Letizia et al reported a non-differentiated ACE activity in human stools. 28 However, neither of these research groups explored this interesting finding, which we have now started to characterize. Innovatively, our study shows that while ACE2 is equally active along the content of the intestinal tract, ACE activity (both N-and C-domains) is higher in the ileal content than in more distal regions or CFPs.…”

“…In fact, to our knowledge, there are only two scientific papers that assessed the presence/activity of ACE in the human ileal fluid 27 and human stools of healthy individuals, this being altered in patients with celiac disease. 28 No one has looked for fecal ACE2. So, the aim of this work was to investigate the concentration and catalytic activity of ACE and ACE2 throughout the intestinal content and excreted fecal pellets of Wistar rats, and to compare the results on the intestinal content with that of the corresponding intestinal tissue.…”