In the review of  the literature it was generalized the data due to the classification and characterization of antioxidant protection system of animals body. This model combines a number of different by its nature substances. Each of the components of the antioxidant system operates in close relationship with its other structural elements, harmoniously, and in many cases complements and in many cases - enhances the action of each other. Glutathione system forms functional basis of antioxidant defense system, constituent elements of which has its own glutathione and enzymes, which catalyze the reaction of its reverse transformation (oxidation ↔ recovery). Glutathione peroxidase, glutathione reductase and glucose-6-phosphate dehydrogenase are attributed to these enzymes.Most researchers conventionally distributed antioxidant defense system in enzyme and non-enzyme. Catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, glutathione transferase and other enzymes are included to enzymatic link of antioxidant defense system. Fat-soluble vitamins A, E and K, water-soluble vitamins C and PP, biogenic amines, glutathione, carotenoids, ubiquinone, sterols are included to  non-enzyme system. As the enzyme, as non-enzyme antioxidant defense system is present in the bloodstream. The activity of enzymatic antioxidant system is well regulated and depends on the age of the animals, physiological condition, the dynamics of hormone, synthesis intensity of antioxidant enzyme, pH  medium, the presence of coenzymes, inhibitors, activators, and other factors. Non-enzyme link of antioxidant system does not need so many regulators as the most chemical substance - antioxidant - enters into chemical reaction with the radical. The rate of reaction may be only changed.

This article presents the results of research on the influence of cadmium loading on the state level of enzymatic and non-enzymatic antioxidant links of the antioxidant defense system of the organisms of young cattle, such as the activity of catalase, superoxide dismutase, glutathione peroxidase, glutathione levels, selenium, vitamins A and E. It was found that feeding bull calves with cadmium chloride at doses of 0.03 and 0.05 mg/kg of body weight helped to reduce both the enzymatic and non-enzymatic link of antioxidant protection (superoxide dismutase 31%, catalase 13%, glutathione peroxidase 23%, reduced glutathione 10%, vitamin A 28%, vitamin E 31%, selenium 20%). Toxic effects of cadmium promotes change in steady-state concentrations of radical metabolites О2–,ОН˙, НО2˙, which, in turn, trigger the process of lipid peroxidation. The lowest level of indicators of antioxidant defense system in the blood of young cattle was registered on the sixteenth and twenty-fourth days of the experiment, which is associated with increased activation of lipid peroxidation and the disturbaance of the balance between the antioxidant system and lipid peroxidation intensity. The activity of the antioxidant defense system in the blood was different for calves fed with cadmium chloride at doses of 0.03 and 0.05 mg/kg of animal mass. The more cadmium chloride in the feed, the lower the activity of the antioxidant defense system of the calves’ organisms was registered. Thus cadmium chloride depresses the antioxidant defense system, which specifically involves lowering the activity of enzymatic links (catalase, superoxide dismutase, glutathione peroxidase) and non-enzymatic links (reduced glutathione, selenium, vitamins A and E).

The results of study of toxicity of the newly created «Injectable Mevesel» during acute and chronic experiments are presented. There were no lethal cases at intragastric and intramuscular injections, only short-time inhibition of laboratory animals receiving the drug at a dose of 10.0 ml was observed. There were no lethal cases of test animals during the experiment in the conditions of study of accumulation properties of «Injectable Mevesel». Total average dose of the drug administered made up 162500 mg/kg, and accumulation coefficient was respectively 5.3. In the study of morphological blood parameters of rats after intramuscular injection of «Injectable Mevesel» in increasing doses, probable increase in neutrophils count by 36.1%, and probable reduction in lymphocytes count by 15.2% were found. Administration of the drug in increasing doses significantly affects the functional state of internal organs of experimental animals (liver) and causes significant degradation of the membranes of hepatocytes, as evidenced by increased activity of intracellular ALT, AST enzymes and alkaline phosphatase. Therefore, new domestic drug «Injectable Mevesel» created by us belongs to class 4 toxicity criteria, i.e. low-toxic substances. Наведено результати дослідження токсичності новоствореного препарату «Мевесел-ін'єкційний» у го-строму і хронічному досліді. За умов внутрішньошлункового і внутрішньо м´язового введення загибелі білих щурів не було, лише встановлено короткочасне пригнічення лабораторних тварин, яким задавали препарат у дозі 10,0 мл. За умов дослідження властивостей мевеселу-ін'єкційного в дозах щодо кумуляції загибелі до-слідних тварин протягом досліду не виявлено. Сумарно введена середня доза препарату становила 162500 мг/ кг, а коефіцієнт кумуляції був відповідно -5,3. При дослідженні морфологічних показників крові щурів після внутрішньо м´язового введення препарату "Мевесел-ін'єкційний" у зростаючих дозах, встановлено вірогідне збільшення кількості нейтрофілів на 36,1 % та вірогідне зменшення кількості лімфоцитів на 15,2 %. Введення препарату у зростаючих дозах суттєво впливає на функціональний стан внутрішніх органів дослідних тва-рин (печінки) та викликає деструкцію мембран гепатоцитів, про що вказує підвищення активності внутріш-ньоклітинних ензимів АлАТ, АсАТ і лужної фосфатази. Отже, створений нами новий вітчизняний препарат "Мевесел-ін'єкційний" належить до 4-го класу токсичності, тобто до малотоксичних речовин.Ключові слова : фармакологія, токсикологія, кров, щурі, миші, препарат "Мевесел-ін'єкційний".

From the standpoint of modern ideas, the normal functioning of the poultry body and full implementation her of the genetic potential is impossible without the presence of selenium in the diet. The biochemical diversity of selenium puts it in a number of priority trace elements. Scientists who were studying the effects of selenium on poultry body and paid relatively little attention to the quality of the meat. In scientific experiment are studied the effect of additives different doses of selenium in compound feed on the chemical composition, energy and biological value of meat of the cross chickens-broilers COBB 500. Introduction of selenium into the feed for broiler chickens in the doses which are studied (0.3 mg/kg, 0.4 and 0.5 mg/kg) did not significantly affect to the quality of their muscle tissue although it positively affected on some indicators that characterizing its chemical composition, nutritional and biological value. Among the experimental groups, the best meat quality indicators were in the second group of chickens for which was introduced into the feed selenium from the calculation of 0.3 mg/kg. When feeding mixed feeds with selenium additives to broiler chickens it was found that it is likely to increase the concentration of this trace element in muscle tissue by 60.6-100% (P?0.001), which does not exceed the maximum permissible level (MPL). Consumption of selenium-enriched meat of broiler chickens within the limits of the physiological norms recommended in Ukraine will ensure the daily requirement of an adult in this trace element by 23.6-29.4%. This meat product can be especially useful for people who live in regions with low levels of selenium in the natural environment.

The study aimed to establish the parameters of chronic toxicity of the newly developed drug based on phosphodiesterase-3 inhibitor and ethylmethylhydroxypyridine succinate in experiments on laboratory animals. The analysis was performed on white sexually mature young male Wistar rats weighing 170–185 g. Four groups of white rats were formed. The first experimental group was administered Bendamine based on a phosphodiesterase-3 inhibitor and ethylmethylhydroxypyridine succinate at a therapeutic dose. Rats of the second experimental group were injected with the experimental drug in a 5-fold dose. Rats of the third experimental group were administered the drug in a 10-fold dose. The fourth group served as control. The study of chronic toxicity of Bendamine in white rats indicates that long-term 30-day administration in therapeutic doses or 5-fold dose does not cause clinical signs of poisoning, as evidenced by the physiological limits of fluctuations in the studied morphological and biochemical parameters of blood rats. Prolonged administration of Bendamine to rats in a 10-fold dose is accompanied by a slight suppression of the body's physiological state, as indicated by a decrease in total erythrocytes and hemoglobin by 10.1 % against an increase in white blood cells by 59.8% (P < 0.001). In addition, there was a decrease in the functional state of the liver, as evidenced by a probable reduction in total protein by 8.0% and urea – by 13.5 %, as well as an increase in ALT, AST, and alkaline phosphatase by 31.6 %, 7.4 %, and 53.9% respectively. Probable changes in the coefficients of liver and spleen mass have been established. When administered intramuscularly to rats with the drug Bendamine for 30 days, the macroscopic and microscopic structure of the studied internal organs is preserved in all groups of animals. The second experimental group revealed reversible moderate histostructural changes in the liver and kidneys. In rats treated with ten times the therapeutic dose of the drug, histologically found hemodynamic disorders and alterations in dystrophic nature, mainly of protein origin, with focal localization in the parenchyma of the liver, kidneys, and myocardium, which in most cases are reversible and result from the compensatory response. Macroorganism on the introduction of a high dose of the study drug.