Expression and cellular localisation of diamine oxidase in the gastrointestinal tract of pigs

Inflammation Research -     

Effects of unfractionated and low molecular weight heparins on diamine oxidase release

Inflammation Research -     

Analysis of mammalian diamine oxidase genes

Inflammation Research -     

Purification of human intestinal diamine oxidase

Inflammation Research -     

Analysis of the glycosylation of porcine diamine oxidase

Inflammation Research -     

Monoamine and diamine oxidase activities in atopic eczema

Increased plasma histamine levels were associated with significantly lowered diamine and type B monoamine oxidase activities in platelet rich plasma of atopic eczema patients.     

Highly efficient purification of porcine diamine oxidase

Diamine oxidase (DAO) is a member of the class of copper-containing amine oxidases and catalyzes the oxidative deamination of histamine and other biogenic amines. The enzyme from porcine kidney was purified by consecutive chromatography on concanavalin A Sepharose, heparin Sepharose and Mono Q. Besides being simpler and faster than previous methods, this new purification scheme results in a homogenous product with a considerably higher yield and allows the rapid purification of large amounts of DAO from mammalian tissues. The availability of sufficient pure protein will greatly facilitate future studies of the structure and function of the enzyme.     

Inhibition of diamine oxidase activity by heparins

Inflammation Research -     

Complex formation of human placental diamine oxidase

Inflammation Research -     

Recurrent urticaria and reduced diamine oxidase activity

An abnormal metabolism of histamine has been suspected in urticaria and the role of diamine oxidase (DAO: histaminase) is therefore of interest. We have studied DAO activity in plasma and jejunal biopsy material and have measured the post-heparin DAO release in 11 control subjects and nine with recurrent urticaria, three of whom had had concurrent episodes of abdominal pain. Two of the nine urticaria subjects had only a minimal rise in plasma DAO activity after heparin, three had a response which was at the lower end of the normal range, and four were normal. In four out of five cases in which jejunal biopsy activity was obtained, there was concordance between mucosal DAO activity and the post-heparin plasma DAO response. Those with abdominal symptoms had abnormally low mucosal DAO activity and the subject who was most severely affected had proven episodes of small bowel oedema.     

Inhibition of serum diamine oxidase discloses a constitutive putrescine release from cultured vascular smooth muscle cells

OBJECTIVE: To determine if putrescine and the higher polyamines spermidine and spermine are released from cultured vascular smooth muscle cells. MATERIAL: Vascular smooth muscle cell line A7r5. TREATMENT: Cells were treated with aminoguanidine (10 or 100 microM) for 1 to 24 h with or without fetal calf serum (10%) present in the culture medium. METHODS: Cellular and medium concentrations of polyamines were determined by liquid chromatography. Total cellular protein was determined by the Bradford procedure. Student's two-tailed t-test was used for statistical calculations. RESULTS: A constitutive release of putrescine was disclosed within 5 h if serum diamine oxidase was inhibited by 10 microM aminoguanidine. The release was linear with time for 24 h and specific for putrescine in the sense that the higher polyamines spermidine and spermine, despite similar cellular concentrations, were not released. Similar amounts of putrescine were released from the smooth muscle cells whether or not culture medium contained serum. Cells, that had been cultured in medium from which fetal calf serum had been omitted for last 48 h, contained less putrescine, spermidine and protein than those that persisted in medium that contained serum. CONCLUSION: A constitutive putrescine release from vascular smooth muscle cells is disclosed in the presence of aminoguanidine.     

Inhibition of diamine oxidase by antimalarial drugs

The antimalarial drugs amodiaquine, quinacrine and chloroquine inhibit the catabolism of putrescine by the rat. Amodiaquine, the most potent of the three, does so in a dose-dependent fashion. This is attributed to the action in vivo of the drugs on diamine oxidase, an enzyme that is inhibited by them in vitro.     

Eosinophil diamine oxidase activity in acute inflammation in humans

Eosinophil diamine oxidase, histaminase, activity was assayed in acute inflammatory states and correlated to disease activity. Correlation to serum and urine histamine, metabolites of histamine and granulocyte histamine metabolizing enzymes was also studied. Using a radiochromatagraphic assay, diamine oxidase, histaminese, activity was determined in human peripheral blood eosinophils from patients with acute inflammatory states including active asthma, cold-induced urticaria and parasitic infestation; eosinophils from non-active asthmatic patients and normals were used as controls. Eosinophils were purified over a metrizamide discontinuous (16–30%) gradient. Total eosinophil histaminase activity was increased two- to three-fold in patients with active disease and returned to lower levels in eosinophils from patients without active disease or with treated disease. Thus, the induction of eosinophil histaminase might be a control mechanism for the inflammation induced by histamine during these acute inflammatory states.     

Estrogenic regulation of diamine oxidase activity in rat uterus

Diamine oxidase activity was studied in female rat tissues during the estrous cycle and after 17 -estradiol administration. During the estrous cycle, uterine and hepatic enzyme activities were highest at proestrus and lowest at estrus, when estrogen plasma levels are known to be respectively high and low. The administration of 17 -estradiol to ovariectomized rats caused a rapid and prolonged increase in enzyme activity in uterus and only a transient, increase in the liver. Such increases were prevented by cycloheximide and by actinomycin D administration. No changes were observed in renal enzyme activity during estrus or after hormone treatment. Our data suggest that estrogens regulate, diamine oxidase activity in rat uterus by a mechanism of enzyme induction.     

Histaminase (diamine oxidase) activity in human cataract

Inflammation Research -