[Effects of selenium on endogenous synthesis of N-nitrosamines and toxicity of nitrites in rats]. / Vliianie selena na éndogennyi sintez N-nitrozaminov i toksicheskoe deistvienitritov u krys.

Male Wistar rats were fed selenium (0.2, 2.9 or 5.5 mg/kg of dry feed) in the form of selenomethionine. They also received for 6 weeks amidopyrine (33 mg/kg b.w.) and/or sodium nitrite (20 mg/kg b.w.) administered intragastrically. The quantitation of endogenously synthetized volatile nitrosamines in the stomach, selenium in the serum, biochemically evaluated nitrite and nitrosamines toxicity revealed an inverse relationship between feed selenium concentrations and the amount of endogenously produced nitrosodimethylamine from equal precursor doses. A protective selenium effect on methemoglobin-producing action of nitrite ions was established. It is shown that introduction of precursors induces increased body need in selenium.

[Effect of nitrates on the dynamics of methemoglobin formation in rats of various ages]. / Vliianie nitratov na dinamiku metgemoglobinoobrazovaniia u krys razlichnykh vozrastnykh grupp.

Wistar male rats with body mass of 50-83 g and 327-365 g were treated per os with solution of sodium nitrate in single dose of 500 or 1000 mg/kg of body mass (on the base of nitrate-ion). The level of methemoglobin (MH) and activity of methemoglobinreductase (MHR) in blood were analyzed. It was shown that level of MH in blood of young immature rats was increased with appearance of two peaks after ingestion both doses of nitrate. The appearance of two peaks of MH in mature rats was observed only after the high dose of nitrate. Low dose of nitrate caused increase of MH concentration only one time. Both doses of nitrate did not effect on MHR activity in rat blood.

[Changes of anaphylactic sensitivity to some food proteins and aflatoxin B1 in guinea pigs]. / Izmenenie anafilakticheskoi chuvstvitelnosti morskikh svinok k nekotorym pishchevym belkam pod vliianiem aflatoksina B1.

The study was made of aflatoxin B1 effect on guinea pig alimentary anaphylaxis to chicken ovalbumin (CO) and pasteurized cow milk (PCM), of CO-specific IgG antibody levels, some serum indices, sensitivity of the animals to LD50 histamine. In response to aflatoxin B1 alimentary anaphylaxis both to CO and PCM became more severe, lethality of the anaphylaxis to CO being in logarithmic relation to aflatoxin B1 dose (p < 0.05); specific IgG-antibodies to CO grew in number; serum total protein increased against unchanged levels of albumins; the activity of gamma-glutamyltransferase inhibited; histamine shock gained severity, its lethality being logarithmically related to the aflatoxin B1 dose. The discussion covers mechanisms underlying the animal allergic reactivity responses to aflatoxin B1.

[Biological value and assimilation of sarcoplasmic protein concentrates from commercial fish products and the effect of their consumption on rats]. / Biologicheskaia tsennost' i usvoiaemost' kontsentratov sarko- plazmaticheskikh belkov promyslovykh ryb i vliianie ikh potrebleniia na organizm krys.

The biological value of 3 concentrates of sarcoplasmatic proteins from industrial fish (minthal, cod, putassu) was assayed in the 4-week experiment on growing male Wistar rats by the methods of counting the coefficients of protein effectiveness and pure protein effectiveness that comprised 100, 110 and 110% in relation to the corresponding parameters obtained with casein. The actual assimilation of the fish product proteins proved to be significantly higher than that of casein. Hypocholesterolemic and hypolipidemic effects of the protein products studied are, probably, caused by the presence of pectin.

[Research on xenobiotic metabolism for assessing the quality of protein-containing products from plant raw material produced through biotechnology methods]. / Issledovanie metabolizma ksenobiotikov dlia otsenki kachestva beloksoderzhashchikh produktov iz rastitel'nogo syr'ia, poluchaemykh metodami biotekhnologii.

Activity of microsomal hydroxylation and conjugation enzymes was studied in the liver of rats that received food concentrate of protein from sunflower groats (SPC) produced in the USSR, and soya protein isolate (SPI) produced by Ralston Purina, USA. SPC consumption during 3 months was attended by elevation of cytochrome-450 content, and activity of microsomal hydroxylation and uridinephosphate-glucuroniltransferase (UDP-GT) in hepatic microsomes, that may evidence the presence in SPC of chemical compounds of natural origin, or chemical modification of the own amino-acid products. SPI did not influence activity of microsomal hydroxylation enzymes, but it raised UDP-GT activity. Both protein products produced no effect on activity of enzymes associated with glutathione metabolism--glutathione-S-transferase and glutathione-reductase in hepatic cytosol. However, SPC and SPI induced a manifold rise in glutathione-peroxidase activity in cytosol of the liver and blood that indicates the presence of the trace element selenium in the products studied.

[The biological value of the proteins of dairy products with varying contents of lactose]. / Biologicheskaia tsennost' belkov molochnykh produktov s razlichnym soderzhaniem laktozy.

In experiments on growing Wistar male rats biological value of proteins was estimated in 5 milk products containing proteins: "Detolact", "Humana O", "Novolact MM", lactalbumin and "Dialact" containing from 17 to 58% of lactose. The final level of lactose in the ration (7% of protein by mass) varied from 4.4 to 30.6%. The parameters of protein biological value in the tested products did not significantly differ from those of the control protein (casein) that has proved the validity of using rats for investigation of biological value of proteins in the rations containing up to 30% of lactose.

[The biological value and assimilability of the proteins of the Guinea bean and its compositions with rice proteins]. / Izuchenie biologicheskoi tsennosti i usvoiaemosti belkov gvineiskoi fasoli i ee kompozitsii s belkami risa.

Experiments were conducted in rats. It was established that colored bean produced a higher inhibitory effect on the rat growth than white bean. The effect of mutual enrichment of proteins was recorded when proteins of bean and rice were combined in the ratio calculated and tested in rats. To the authors' opinion, this phenomenon has not only scientific but also practical importance.

[Substantiation of an optimal protein quota in the diet of patients with chronic pancreatitis based on the study of nitrogen balance]. / Obosnovanie optimal'noi kvoty belka v ratsione bol'nykh khronicheskim pancreatitom po dannym issledovanii azotistogo balansa.

Based on nitrogenous balance studies performed under the clinical conditions in patients with chronic pancreatitis given the diet with different protein content (80, 120 and 150 g/day) it is recommended that the optimal protein quota should be equal to 114-120 g/day in the diets intended for patients' population in question.

[Effect of the casein content in the feed on the growth and state of the nitrogen balance of white rats]. / Vliianie soderzhaniia kazeina v korme na rost i sostoianie azotistogo balansa belykh krys.

Investigations conducted on albino rats of the Wistar line established a marked relation between the growth rate, consumption of food and the nitrogen balance, on the one hand, and the proteins content in the feeding stuff, on the other. Then the maximum consumption and the gain of body mass was observed with 22--25 per cent of the casein protein content.