STRUCTURAL AND FUNCTIONAL CHANGES IN TONGUE TISSUES UNDER PER OS ADMINISTRATION OF HIGH DOSES OF LEAD ACETATE

The main purpose of this study was to evaluate the structural transformation in rats’ tongue tissue after oral administration of lead salts. Under the conditions of acute experiment during 5 days Wistar rats were orally administered the lead acetate solution in the amount of 24 mg per day. Histological studies were carried out at OSMU upon the completion of the experiment. Effect of toxic doses of lead results in symptoms of both hyperkeratosis and destruction of tongue tissue. It is assumed that the oxidative stress and tissue irritation, induced by lead intoxication, causes pathological changes in the shape, height and number of filiform papillae of the tongue. This results in hyperkeratosis, hydropic degradation of the epithelium and in the presence of an inflammatory infiltrate in the connective tissue.

EFFECT OF LEAD ON STRUCTURAL CHANGES IN LIVER OF WISTAR RATS UNDER THE CONDITIONS OF ACUTE EXPERIM

The purpose of this study was to evaluate the structural transformations of Wistar rats liver after oral administration of lead salts. Under the conditions of acute experiment during 5 days the Wistar rats were orally administered the lead acetate solution in the amount of 3 mg/kg. Histological studies were carried out at OSMU upon the completion of the experiment. Effect of toxic doses of lead causes symptoms of both steatosis and hydropic degeneration of the liver. It is assumed that the appearance of hepatic steatosis reflects the reaction of hepatocytes to hemic hypoxia caused by the action of lead, while the signs of hydropic degeneration expressed in varying degrees reflect its direct toxic effect.

Comparative toxicity of trophic exposures to polybrominated compounds (2, 4, 6 - Tribromophenol and BDE-209) to Oreochromis niloticus (Linnaeus, 1758)

In the last decades, there has been an increase in demand for new polymers, including flame-retardants compounds, to meet fire prevention by international safety standards. The decabromodiphenyl ether (BDE-209) is a polybrominated diphenyl ether (PBDE) congener still in use worldwide. This compound presents lipophilic properties and so is easily bioaccumulated in the food chain. The 2, 4, 6 - Tribromophenol (TBP) is a PBDE metabolite also used as pesticide and flame-retardant for wood conservation. In the current study, the acute and chronic toxicity of BDE-209 and TBP was evaluated in Oreochromis niloticus through the analyses of redox unbalance, neurotoxicity and histopathological biomarkers after acute (24, 48, 72 and 96 h) and chronic (90 days) exposures to 0.5, 5 and 50 ng/g of the PBDEs. The results showed effects in GST activity and damage to biomolecules in both acute and chronic exposures. Histopathological findings were observed in the acute experiment, while hepatocyte lesions were found in both experiments. Only BDE-209 presented neurotoxic effects. The current study revealed new endpoints related with polybrominated compounds in fish, highlighting the needs to review the risk of exposure to biota and human populations.

TOXICOLOGICAL ASSESSMENT OF THE PREPARATION SUBMASTIN-KRS IN AN ACUTE EXPERIMENT ON LABORATORY ANIMALS

The article presents the results of toxicometric assessment of Submastin-KRS in an acute experiment on white laboratory rats and mice when it is intragastrically and intramuscularly administered. The preparation was administered once into the stomach using a metal atraumatic probe at a dose range from 2000,0 to 27 mg/kg. A single injection volume was 500,0 ml (mouse) and 0,5 ml (rat); intramuscularly – at doses from 5,0 to 1200,0 mg/kg in a volume of 21 ml per mouse and 250,0 ml per rat. The animals of the Placebo group, administered the preparation in the same volume and by the same method of administration, received sterile isotonic sodium chloride solution. It was found that in case of the tested methods of administration in the range of the studied doses of the preparation, there was no deaths of animals, therefore, the mean lethal dose (LD0,25) of the preparation Submastin-KRS was not determined. Consequently, the experimental data obtained make it possible to classify the dosage form of the preparation Submastin-KRS to low-hazard substances.

Vasorelaxant and Antihypertensive Effects of Mentha pulegium L. in Rats: An in vitro and in vivo Approach

Aims and objective: The aim of the study was to investigate the effect of aqueous aerial part extract of Mentha pulegium L. (Pennyrile) (MPAE) on arterial pressure parameters in rats. Background: Mentha pulegium is a medicinal plant used to treat hypertension in Morocco. Material and methods: In the current study, MPAE was prepared and its antihypertensive activity was pharmacologically investigated. L-NAME-hypertensive and normotensive rats have received orally MPAE (180 and 300 mg/kg) during six hours for the acute experiment and during seven days for the sub-chronic treatment. Thereafter, systolic, diastolic, mean arterial blood pressure and heart rate were evaluated. While, in the in vitro experiment, isolated denuded and intact thoracic aortic rings were suspended in a tissue bath system and the tension changes were recorded. Results: A fall in blood pressure was observed in L-NAME-induced hypertensive treated with MPAE. The extract also produced a dose-dependent relaxation of aorta pre-contracted with NE and KCl. The study showed that the vasorelaxant ability of MPAE seems to be exerted through the blockage of extracellular Ca2+ entry. Conclusion: The results demonstrate that the extract of pennyrile exhibits antihypertensive activity. In addition, the effect may be, at least in part, due to dilation of blood vessels via blockage of Ca2+ channels.

First experience in implantation of a mechanical circulatory support device based on a disk-type pump: an acute experiment

Objective: to carry out the implantation of an artificial left ventricle of the heart based on a disk-type pump in an acute experiment on a large mammal (mini-pig). Materials and methods. To test the surgical technique of implantation and assess the biocompatibility of the apparatus for mechanical support of blood circulation based on a viscous friction pump, an acute experiment was conducted on an animal. A large mammal (mini-pig weighing 90 kg) was used as an experimental model. The implantation of the pump was performed extracorporeally according to the scheme «the apex of the left ventricle – the descending thoracic aorta». During the experiment, invasive blood pressure, central venous pressure, cardiac arrhythmias, body temperature, blood gas composition, activated coagulation time were monitored. Under the control of transesophageal echocardiography, the pump operation mode was set with parameters – speed 2400–2600, productivity 4 ± 0.5 l/min, average IAD – 70–80 mm Hg. Results. In the course of the experiment, the fundamental possibility of using the developed disk-type pump as a device for supporting blood circulation was proved. For 4 hours, the pump provided adequate hemodynamic parameters with an average productivity of 4 ± 0.5 l/min and 2500 rpm. After 4 hours of operation of the pump in the conditions of inactivated heparin (AST – 114 sec), no blood clots were found between the pump disks. Conclusion The hemodynamics feature of the disk pump allows you to develop sufficient performance parameters to ensure adequate blood circulation. The mechanism of action of the «boundary layer» minimizes the risk of blood clots in the pump cavity. However, the topographic and anatomical features of the pig’s body do not allow experiments with a long observation period.

SAFETY ASSESSMENT OF THE NEW DRUG "MT-6" IN AN ACUTE EXPERIMENT ON WHITE MICE

The article presents the results of assessing the safety of the new drug "MT-6" in an acute experiment on white mice. Experiments to assess acute toxicity were carried out in three series of experiments with intragastric, subcutaneous and intramuscular routes of administration in duplicate. The drug was administered intragastrically once after a 12-hour fasting diet in doses from 5500 to 10000 mg/kg in a volume of 0.5 ml per mouse; subcutaneously – in the dose range from 2000 to 6800 mg/kg in a volume of 0.5 ml per mouse; intramuscularly – in doses from 2000 to 6800 mg/kg in a volume of 0.25 ml per mouse. Control animals were injected with sterile isotonic sodium chloride solution in the same volumes and by the same methods. During the first day after the administration of the drug, the experimental animals were monitored continuously, then for 14 days – 2 times a day. On the basis of toxicometric data obtained during the experiment, the parameters of acute toxicity of the drug "MT-6" were established: with intragastric administration LD50 7828.5 mg/kg, with subcutaneous administration LD50 4994.1 mg/kg, with intramuscular LD50 3841.9 mg/kg. Based on this, it was concluded that the investigated drug belongs to GOST 12.1.007-76 to the 4th hazard class – low-toxic substances; according to Hodge and Sterner (1943) to the 5th hazard class – practically non-toxic substances; according to Sidorov K.K. (1977) – to the 6th class of hazard – relatively harmless substances.

ASSESSMENT OF THE INFLUENCE OF THE NEW STRESS CORRECTOR ON THE LABORATORY ANIMAL ORGANISM IN THE ACUTE EXPERIMENT

The article presents the results of acute toxicity of a new complex preparation in various ways of its introduction to laboratory white mice and rats. It was determined that a single intragastric and intramuscular administration of the maximum doses of the preparation does not cause a clinical picture of toxicosis and death of laboratory animals, on the basis of which the preparation is classified as hazardous class (GOST 12.1.007-76 “Harmful substances”) - low-hazard substances.

Influence of sodium glutamate and food additives on the activity of smooth muscles of the stomach, the intestines and the cardiac activity of rats

The present work investigates the action of food additives: sodium glutamate E-621 (720 mg/kg), sodium benzoate E-211 (30 mg/kg), tartrazine E-102 (45 mg/kg) on the modulation of the heart rate (СR) and the activity of smooth muscles of the stomach and the colon in acute experiments on rats. Narcosis – thiopental sodium, 70 mg/kg is made intraperitoneally. It is established that the unitary administration of each of the additives into the stomach separately or everywhere results in precise effects of increase or decrease of total potentials of smooth muscles (PSM) without CR changes. After introducing glutamate into the stomach intravenously infusion adrenaline (Adr, 10 mkg) causes CR to increase more significantly, if all additives are introduced into the stomach, and then Adr. PSMs after the application of Adr were often more stimulating. Later, a subsequent significant influence on the effects of long use of additives in a diet is established. As it has appeared, the application of adrenaline in finishing acute experiment (after a month of feeding by additives) is accompanied not by amplification(strengthening), and, on the contrary, by the disorder of the heart work: CR gradually falls, arrhythmia arises, fibrillations of a myocardium and then cardiac contractions stopped in 12 of 16 experiments. These processes are associated with decreas ing the background activity on an electrocardiogram of the average area of RST (in the control 149 mkV/s, in a month of experience 80 mkV/s, р < 0.05) and waves Т (82 and 43 mkV/s, respectively, р < 0.01) without significant changes of their duration. The increase or decrease of the RST area is seen and Т is marked at the action of special ADR on the stomach additives. It is supposed that a long use of food additives serves as the precondition for dysfunctions in the heart work in the situations connected to a fast increase in the blood of catecholamines – in the conditions of various stresses, adverse influences of factors of the environment.