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Biomedical subjects

V K Mazo

Publications and source records attributed to V K Mazo.

99 records · Page 6Linked to original sources
PubMedDate not supplied

[Characteristics of anaphylaxis in fasting rats].

The effect of 4-day fasting was studied in male Wistar rats (200-150 g) sensitized by ovalbumin on anaphylaxis manifestations in vivo, antigen-dependent histamine secretion by mast cells in vitro, concentration of serum specific IgG antibodies. The fasting ended by a shocking allergen dose. It is shown that in the condition of food deprivation anaphylactic severity significantly lowered as well as antigen-dependent histamine secretion by mast cells. No changes were seen in the levels of specific antibodies in the serum.

Anaphylaxis↗
PubMedDate not supplied

[Permeability of the gastrointestinal tract to macromolecules in experimental anaphylaxis].

Rats were sensitized with single or multiple intraperitoneal administration of chick's egg ovalbumin (OA) or DNP-conjugated bovine serum albumin (DNP-BSA) on aluminium. The animals were challenged 14-28 days thereafter by intragastric or intravenous administration of respective antigens. Gastrointestinal barrier permeability was tested with macromolecular probes: OA and polyethylene glycol (PEG)-4000. The increase of permeability was revealed in animals sensitized with DNP-BSA and challenged intragastrically. The morphological view of intestinal damage included epithelial edema, exfoliation on the upper third part of the villi and also increases in the count of transepithelial lymphocytes. In OA-sensitized rats, the gastrointestinal permeability to PEG-4000 grew only following multiple sensitization and intravenous (or multiple intragastric) challenge with this antigen.

Anaphylaxis↗
PubMedDate not supplied

[Effect of various dietary proteins and some amino acids on formaldehyde sensitization in guinea pigs].

Guinea pigs were fed for 14 days with semisynthetic diets containing protein (milk casein: 1.5, 30, 45% and soya protein: 4, 18 and 36% of total energy) or with different amounts of L-methionine (Met) and glycine (Gly). Simultaneously with diets feeding the animals were sensitized epicutaneously by formaldehyde (F). The sensitization to F was evaluated by leukocyte specific lysis reaction (RSLL). Hepatic formaldehyde dehydrogenase (FDH) activity and reduced glutathione (GSH) content were measured. The sensitization to F decreased when the animals were fed with growing amount of plant or animal protein, or with high amount of Met and normal level of Gly. FDH activity increased in sensitized animals compared to non-sensitized irrespective of the diet fed. Hepatic GSH pool significantly grew with an increase in both proteins level and in sensitized animals also with growing Met and Gly intake. GSH pool did not change in sensitized animals fed with different amounts of amino acids. It is suggested that high dietary protein and amino acids protection against F-sensitization was mediated by elevated tissue GSH though optimal consumptions of Met and Gly were different. Hepatic FGH activity together with RSSL may be considered as a sensitive biochemical criterion of experimental F sensitization.

Aldehyde Oxidoreductases↗
PubMedDate not supplied

[Experimental model of impaired gastrointestinal macromolecular permeability].

Gastrointestinal macromolecular permeability for polyethylene glycol (PEG)-4000 was studied in Wistar rats with resected distal portion of the small intestine, experimental colitis induced by chemical toxicant (acetic acid) and in rats receiving oral ethyl alcohol. Gastrointestinal permeability in animals with resection transiently increased during the first two weeks after operation and returned to normal thereafter. Colitis induction resulted in marked (2.5-fold) growth of permeability for PEG-4000 on day 7 and in a less significant increase on day 21. In animals exposed to ethyl alcohol no changes in macromolecular permeability were noted for PEG-4000 and food protein (chick's egg albumin). It is concluded that the model of colitis induced by chemical toxicants is most suitable among the models tested for experimental research on dietetic correction of altered macromolecular permeability.

Animals↗
PubMedDate not supplied

[Effects of dietary fat composition on food anaphylaxis and formaldehyde sensitization in guinea pigs].

Adult guinea pigs were fed for 10-14 days with synthetic diets, fat constituting 11% of its total energy. Dietary fat was composed of coconut, corn, dairy and soybean oils mixtures with ratio of polyunsaturated fatty acids (PUFA) omega-6 to PUFA omega-3 equal to 24.2 (K1) or 5.53 (K2). The animals were sensitized orally by pasteurized cow milk (PCM) or epicutaneously by formaldehyde (F) during these diets feeding. The degree of the sensitization was assessed in the reaction of active anaphylactic shock (AAS) in PCM-sensitized animals and in the reaction of leukocytes specific lysis (LSL) in F-sensitized guinea pigs. In the latter pigs the concentration of serum antibodies (Ab) against dietary soya protein was measured by ELISA. Animals fed by K1 and K2 were also tested for histamine mean lethal dose resistance. The lowest lethality in AAS, number of convulsions, of positive LSL cases and Ab level were found in animals fed by K1 compared to both K2 and to animals fed by common animal chew. Resistance to histamine was similar in K1 and K2 groups, but was significantly higher compared to control (chew) group. In convulsion, the changes in PUFA omega-6/PUFA omega-3 ratio have marked effect on different indices of allergic sensitivity.

Anaphylaxis↗
PubMedDate not supplied

[Vitamin metabolism in rats in the early period after a single whole-body gamma irradiation].

A single whole-body gamma irradiation (4 Gy) of rats with the initial deficiency in vitamins B1 and B2 had no effect on the contents of vitamins C, A, and B1 in the blood plasma, liver, or testicles within 42 h after irradiation. The content of vitamin E remained unchanged in the blood plasma but increased in testicles. The contents of vitamin B2 remained unchanged in erythrocytes and liver, decreased in testicles, and its excretion with urine increased more than twice. The content of reduced glutathione in liver, small intestine mucosa, and erythrocytes decreased.

Animals↗