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Ovomucoid reaction

Other inhibitor studies, using dextran to induce the anaphylactoid reaction, also implicated histamine as a mediator of the reaction [90, 125, 151, 344-347, 463,464]. It has been suggested that antihistamines prevent the dextran reaction by reacting quantitatively with the polymer in the blood [224, 348], but no such mechanism of action has been proposed in the case of the egg-white or ovomucoid reactions. [Pg.354]

B Elimination has been used to show differences among the disulfide bonds in various proteins including the ovomucoids (54). The e-elimination reaction has also been used to replace the hydroxyl group of the essential serine residue of subtilisin with a sulfhydryl group (55). The thiolsubtilisin had a small fraction of the activity of subtilisin but it has been quite useful in mechanistic studies of the serine and sulfhydryl proteases. [Pg.160]

O er flour additives have been reported as cause of immediate contact reactions in bakers such as sorbic acid and, in some countries, ammonium persulphate [64]. Egg allergy with immediate contact reactions and respiratory symptoms have been reported in two confectionery workers after handling egg white [43]. One of them complained of gastrointestinal and mouth symptoms after ingestion of eggs. Skin tests were positive for different egg components, namely, whole egg, egg white, yolk, ovoalbumin and ovomucoid. Specific IgE RAST to egg white and yolk was found. [Pg.204]

Although egg-white and ovomucoid were the first substances found to ehcit an anaphylactoid reaction in the rat, many other materials are now known to cause a similar inflammatory reaction. For instance, dextran produces a typical... [Pg.348]

There can be no doubt that histamine is released in vivo after the injection of egg-white [171, 217, 218, 483, 549], ovomucoid [60] or dextran [239, 241, 251, 252, 254, 298, 376-378] and also in vitro on tissue incubation with ovomucoid and compound 48/80 [59] or dextran [249] but this biogenic amine is probably not the main mediator in the anaphylactoid reaction. [Pg.354]

Anaphylactoid-inducing agents such as ovomucoid, dextrin and dextran fail to induce a release of kinin from plasma in vitro, although dextran sulphate elicits kinin release under similar conditions but fails to increase vascular permeability in vivo [31]. It is interesting that although ovomucoid is an active anaphylactoid-inducing agent, it is also an inhibitor of the proteolytic formation of plasma kinins. Evidence to date indicates that an important role for plasma kinins in the mediation of the anaphylactoid reaction is doubtful. [Pg.357]

Although the anaphylactoid reaction in normal rats is characterized by gross peripheral oedema a shock-like condition, often resulting in death from haemorrhage in the small intestines, occurs when rats pretreated with thyroxine are injected with egg-white or ovomucoid in contrast, the severity and incidence of the egg-white anaphylactoid reaction is reduced in thyroidectomized animals [401, 404, 670]. The potentiating action of the thyroid hormone may be related to actions in reducing intestinal histaminase and increasing the level of tissue histamine and 5-hydroxytryptamine [220, 481], or to an increased sensitivity of tissues and blood vessels to the release of these 2 amines [491]. [Pg.362]

The administration of egg-white, ovomucoid, dextran or compound 48/80 to adrenalectomized rats produces a state of severe shock characterized by marked oedema, piostration, cyanosis and often death [89, 90, 120, 122, 243, 246-248, 250, 259, 298, 306, 401, 425, 447, 559, 563, 640]. The reason for this potentiated anaphylactoid response is unknown however, histaminase activity is reduced after adrenalectomy [342] which results in an elevation of tissue histamine [51, 434, 527, 613]. Moreover, adrenalectomy increases the sensitivity of rats to histamine [296, 354, 432, 650, 695] and to 5-hydroxytryptamine [103, 202, 286], 2 amines released during the anaphylactoid reaction. [Pg.362]

E.P.Benditt, S.Bader and M. Arase, Anaphylaxis Versus the Anaphylactoid Reaction Produced by Testis and Ovomucoid in Rats, Fedn Proc. Fedn Am. Socs exp. Biol. 12, 384-385 (1963). [Pg.367]

E.P.Benditt, S.Bader and K.B.Lam, Studies of the Mechanism of Acute Vascular Reactions to Injury. I. The Relationship of Mast Cells and Histamine to the Production of Edema by Ovomucoid in Rats, A.M.A. Archs Path. 60, 104-115 (1955). [Pg.367]

Inhibitor activity is normally determined with commercial animal enzymes, e. g., bovine trypsin or bovine chymotrypsin. The evaluation of a potential effect of the inhibitors on human health assumes that the inhibition of human enzymes is known. Present data show that inhibitors from legumes generally inhibit human trypsin to the same extent or a little less than bovine trypsin. On the other hand, human chymotrypsin is inhibited to a much greater extent by most legumes. Ovomucoid and ovoinhibitor from egg white as well as the Kazal inhibitor from bovine pancreas do not inhibit the human enzymes. The Kunitz inhibitor from bovine pancreas inhibits human trypsin but not chymotrypsin. The data obtained greatly depend not only on the substrate used, but also on the enzyme preparation and the reaction conditions, e. g., on the ratio enzyme/inhibitor. The stability of an inhibitor as it passes through the stomach must also be taken into account in the evaluation of a potential effect (cf. Table 16.15). The Kunitz inhibitor of soybeans, for... [Pg.757]

Reaction of quail and chicken ovomucoids with glucose... [Pg.229]

Free amino- and guanidino-groups. As a model system of protein-sugar Maillard reaction, a powdered sample containing ovomucoid and glucose was incubated at 50 C and 65% relative humidity for various periods from 2 to 20 days. The incubated samples were dissolved in 50 mM Tris-HCl buffer, pH 8.0 and used for chemical and biochemical analyses. [Pg.229]


See other pages where Ovomucoid reaction is mentioned: [Pg.135]    [Pg.9]    [Pg.88]    [Pg.162]    [Pg.215]    [Pg.218]    [Pg.170]    [Pg.31]    [Pg.1756]    [Pg.314]    [Pg.23]    [Pg.158]    [Pg.319]    [Pg.67]    [Pg.36]    [Pg.197]    [Pg.346]    [Pg.346]    [Pg.347]    [Pg.348]    [Pg.351]    [Pg.352]    [Pg.352]    [Pg.354]    [Pg.357]    [Pg.358]    [Pg.358]    [Pg.360]    [Pg.360]    [Pg.361]    [Pg.355]    [Pg.227]    [Pg.229]   
See also in sourсe #XX -- [ Pg.228 , Pg.231 ]




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