Diamine Oxidase: An Overview of Historical, Biochemical and Functional Aspects

Abstract

This article is a review of the historical, biochemical, and functional aspects of the enzyme diamine oxidase (DAO). The amine oxidase DAO, formerly called histaminase, is found in various tissues, but is especially active in the intestinal mucosa. Its function is the oxidative deaminating of several polyamines, essential substances for cell proliferation. DAO is thus a regulating enzyme in rapidly proliferating tissues such a bone marrow and intestinal mucosa. Results from several studies have demonstrated that both ornithine decarboxylase (ODC) and DAO activity rise during adaptive hyperplasia seen after small bowel resection. The ODC-dependent increase in polyamine content and subsequent increase in cell proliferative activity is probably downregulated locally in the villus tip by the increased DAO activity. DAO is normally present in very small amounts in the circulation and its basal plasma levels are positively correlated with the maturity and integrity of the intestinal mucosa. After intravenous administration of heparin, DAO is released from its capillary binding sites in the lamina propria into the peripheral circulation. Measurement of postheparin DAO release enhances its sensitivity and is now extensively studied to assess its value as follow-up or screening test for several enteropathies. Measuring basal as well as postheparin DAO levels has potential relevance following small bowel transplantation. Rejection of the small bowel graft leads to mucosal damage, which could conceivably lead to changes in DAO activity.

A carvacrol–thymol blend decreased intestinal oxidative stress and influenced selected microbes without changing the messenger RNA levels of tight junction proteins in jejunal mucosa of weaning piglets

“…Elevated proinflammatory cytokines, such as interleukin 1β (IL-1β), tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6), can induce the decreased abundance of tight junction proteins including zonula occludens (ZO-1) and occludin and thus undermine the integrity of the intestinal barrier (Al-Sadi et al, 2009;Suzuki et al, 2011). In addition to ZO-1 and occludin, plasma diamine oxidase has been proposed as a sensitive circulating biomarker for monitoring the intestinal mucosal barrier (Wolvekamp and de Bruin, 1994).…”

Iron and copper in male reproduction: a double-edged sword

“…The enzyme is assumed to originate from the prostate and upper genital tract (testis and/or epididymis). As shown by Le Calve et al [60], DAO activity was strongly correlated with a variety of prostatic markers, thus it may be related to significant changes in the spermatozoa metabolism [61].…”

Ischemic post-conditioning attenuates the intestinal injury induced by limb ischemia/reperfusion in rats

“…Limb ischemia-reperfusion injury, leading to changes in the permeability of the intestinal mucosa, may be closely related to the production of excess oxygen free radicals (15,16,23,24). The production of reactive oxygen metabolites during ischemia-reperfusion involves oxidases found in resident phagocytic cells as well as microvascular and mucosal epithelial cells (25).…”