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Biomedical subjects

J Kusche

Publications and source records attributed to J Kusche.

At least 55 records · Page 3Linked to original sources

The importance of human intestinal diamine oxidase in the oxidation of histamine and/or putrescine.

Histamine, naturally methylated histamine and putrescine are good substrates for human intestinal diamine oxidase, N-Methyl-N-formylhydrazine, the constituent of the mashroom poison-gyromitrin is an inhibitor of human intestinal diamine oxidase. Burimamide inhibits more effectively mammalian intestinal diamine oxidases than pea seedling diamine oxidase, beta-aminopropionitrile is a better inhibitor of pea seedling enzyme than mammalian diamine oxidases. This inhibitory differences might be related to preference in histamine or putrescine oxidizing activity of these enzymes.

Amine Oxidase (Copper-Containing)↗

[Experimental occlusion of the superior mesenteric artery: further evidence of the influence of histamine and diamine oxidase in the development of shock (author's transl)].

In shock produced by temporary superior mesenteric artery occlusion the plasma histamine concentration was enhanced following release of the mesenteric blockade. Furthermore, an inhibition of the diamine oxidase catalysed histamine inactivation resulted in an aggravation of the shock development. These processes, already shown in dogs and mini pigs, were also observed in rabbits. Histamine receptor antagonists abolished the effect of the enhanced histamine concentration appearing in the circulation following inhibition of diamine oxidase. In human intestinal tract a fairly similar distribution of histamine and diamine oxidase was found as in the mammals studied. Thus the indicated pathobiochemical processes should be reckoned with in patients suffering from circulatory disorders of the intestinal tract.

Amine Oxidase (Copper-Containing)↗

Comparison of alterations in the histamine-diamine oxidase system during acute intestinal ischaemia in pigs, dogs and rabbits; evidence for a uniform pathophysiological mechanism?

Among various vasoactive substances histamine was also suggested to induce circulatory arrest following superior mesenteric artery occlusion. Thus the involvement of the histamine-diamine oxidase system was studied in intestinal ischaemia using three animal species. In pigs, dogs and rabbits aminoguanidine, the specific inhibitor of diamine oxidase, shortened the survival time after mesenteric infarction. Under these conditions the diamine oxidase activity in the intestinal wall was reduced in animals treated by saline whereas the histamine content was not altered significantly. Plasma histamine levels were increased considerably in the portal vein of pigs during the revascularization period if the animal were pretreated by aminoguanidine. Similar findings were obtained in dogs. It was concluded that in all three species investigated the diamine oxidase protects the organism against the deleterious effects of at least one of its vasoactive substrates-histamine.

Amine Oxidase (Copper-Containing)↗

Diamine oxidase activity in gastric and duodenal mucosa of man and other mammals with special reference to the pyloric junction.

In the gastric mucosa of human subjects and of various mammals methylation was accepted as the main pathway of histamine catabolism. However, augmentation of gastric acid secretion by aminoguanidine, the strong inhibitor of diamine oxidase, indicated an influence of diamine oxidase activity on this secretory process. Therefore a careful reinvestigation of the occurrence of diamine oxidase activity was started from the distal duodenum in the direction of the cardia. In all species studied, diamine oxidase activity decreased from distal duodenum towards the pylorus. In dogs, landrace pigs and in human subjects the diamine oxidase activity clearly exceeded the pyloric borderline gradually becoming zero in corpus or fundus. In rabbits, however, and especially in mini-pigs no diamine oxidase activity was found beyond the pylorus. Among individuals gastric diamine oxidase activity showed a variable prevalence and could not be found regularly in all the subjects. In one patient with prepyloric ulcer a strong influence of pathophysiological processes on gastric diamine oxidase activity could be suspected. Thus, in every alteration of the gastric mucosa under experimental or clinical conditions also an alteration of gastric diamine oxidase activity should be taken into account.

Aged↗

Diamine oxidase activity and histamine release in dogs following acute mesenteric artery occlusion.

Following superior mesenteric artery occlusion and revascularization in dogs all animals died in a circulatory collapse state. However, pretreatment by aminoguanidine, the strong and specific inhibitor of diamine oxidase, accelerated the circulatory break-down significantly and increased the venous plasma histamine concentrattions up to levels which also in normal dogs are effective in the circulatory system. Furthermore, the haematocrit increased significantly more in the aminoguanidine-treated animals than in the dogs treated by saline. No changes in plasma diamine oxidase activity were observed in saline-treated animals during intestinal ischemia and following revascularization. In aminoguanidine-treated animals no enzymic activity could be measured. The results were interpreted by a protective role of intestinal diamine oxidase in intestinal ischemia. Enhancement of the enzymic activity in patients, for instance by heparin, may be helpful in mesenteric infarction disease.

Amine Oxidase (Copper-Containing)↗

Determination of histaminase (diamine oxidase) activity by o-dianisidine test: interference of ceruloplasmin.

Until now o-dianisidine was used as an indicator substance in a test system for the determination of diamine oxidase. More recently, however, this substance was also used to measure ceruloplasmin activity. A study of the test principles revealed that o-dianisidine was the one denominator for both enzymes. As it was found for diamine oxidase the indicator was oxidized via peroxidase mediated H2O2 cleavage. Ceruloplasmin, however, oxidized o-dianisidine directly with resulting free radical formation. An addition of histamine dihydrochloride or putrescine dihydrochloride to an incubation mixture, containing ceruloplasmin as enzyme and o-dianisidine or p-phenylene-diamine as substrates, produced an activation of the enzyme, being more than 10-fold in the presence of 1 X 10(-2) M putrescine at pH 7.0. It was assumed that an allosteric effect of the dihydrochloride component might be responsible for this activation. When the activity of purified diamine oxidase was determined by the o-dianisidine test and by the isotope assay, a very good correlation between both methods was found. But, in a mixture of diamine oxidase and ceruloplasmin, no differentiation between the two enzymic activities by the o-dianisidine test was possible. This observation demonstrated an interference of ceruloplasmin when the o-dianisidine method was used for the determination of diamine oxidase activity. To apply our findings also in vivo the amine oxidase activity increasing in guinea-pig plasma during inflammation, was determined by the o-dianisidine test and by specific methods for some amine oxidase. Despite an enhanced oxidation of the o-dianisidine observed, only an increase of ceruloplasmin activity was found. It was concluded that ceruloplasmin had no 'histaminase activity' as has been assumed by other authors using the o-dianisidine test.

Amine Oxidase (Copper-Containing)↗

[Histamine concentration and diamine oxidase activity in the small intestine in superior mesenteric artery occlusion].

During intestinal ischemia in rabbits histamine concentration and diamine oxidase activity were altered in the intestinal wall and in the perfusate of mesenteric vessels. The results were interpreted as a histamine release and an increased catabolism of diamine oxidase. Thus, the combination of release of vasoactive histamine and partial elimination of a protective enzyme may contribute to the fatal outcome after mesenteric ischemia.

Amine Oxidase (Copper-Containing)↗

Diamine oxydase in rabbit small intestine: separations from a soluble monoamine oxidase, properties and pathophysiological significance in intestinal ischemia.

From all mammals investigated so far only in rabbits diamine oxidase could not be detected in any tissue except the gut. Thus this species was chosen for studying the physiological and pathophysiological function of this enzyme in the gastrointestinal tract. By gel filtration on Sephadex G 50 and G 200 the enzyme was purified 100-fold, separated from a soluble monoamine oxidase, and the properties of the two enzymes were determined. Diamine oxidase from rabbit small intestine deaminated putrecine (Km = 1.3 times 10(-4) M, pH-optimum 6.4-6.9) and histamine (Km = 8 times 10(-5) M, pH-optimum 7.5), but not serotonin, and was inhibited by aminoguanidine, but not by pargyline. Soluble monoamine oxidase from rabbit small intestine catabolized serotonin (Km = 1.8 times 10(-4) M, pH-optimum 8.8) but not putrescine and histamine, and was inhibited by pargyline, but not by aminoguanidine. Based on its properties in vitro intestinal diamine oxidase could inactivate the vasoactive biogenic amine histamine in vivo. To confirm this hypothesis, in rabbits the small intestine was damaged severely by inducing total intestinal ischemia, which occurs as mesenteric infarction also in human subjects and is accompanied by histamine release. Treatment with aminoguanidine and ischemia killed the animals 3-times faster than ischemia alone, which supported our hypothesis on a protective role of intestinal diamine oxidase against histamine.

Animals↗

Oxidative deamination of biogenic amines by intestinal amine oxidases: histamine is specifically inactivated by diamine oxidase.

The ability of the gut to inactivate various amines by oxidative deamination was tested with a 130-fold purified amine oxidase preparation from dog small intestine. Of 34 amines tested, putrescine, benzylamine, cadaverine, and serotonin were the most favourable substrates. Histamine was inactivated rapidly by this enzyme preparation, too. Histamine derivatives methylated at the imidazole nucleus were also deaminated, whereas Nalpha-methylhistamine was only a poor substrate and Nalpha, Nalpha-dimethylhistamine was not a substrate at all. Using a second procedure for the purification of amine oxidases from gut, the separation of a soluble monoamine oxidase from diamine oxidase was achieved by gel filtration on Sephadex G-200. The diamine oxidase deaminated putrescine (Km = 1.3 x 10(-4)M) and histamine (Km = 6.6 x 10(-5)M), but not serotonin, and was inhibited by aminoguanidine, but not by pargyline. The soluble monoamine oxidase inactivated serotonin (Km = 4.5 x 10(-4)M), but not histamine and putrescine and was inhibited by pargyline, but not by aminoguanidine. It was concluded that in dog small intestine (as well as in rabbit small intestine) only diamine oxidase was capable of inactivating histamine by oxidative deamination.

Amine Oxidase (Copper-Containing)↗