Body Of Laboratory Animals Research Articles

PBPK-Model Biodistribution of Gold and Silver Nanoparticles in the Body of Laboratory Animals and Humans at Different Ways of Income

For needs of the modern science, prediction of nanoparticles (NPs) biodistribution is necessary to avoid the disastrous consequences of its uncontrolled usage. For these purposes we have created the mathematical model of NPs’ biokinetics which can predict how much NPs would be in different organs in laboratory animals’ or human’s organism after different ways and regimes of injections. It is based on PBPK-modelling conception where the blood is the main transport of NPs and organs or tissues are proposed as compartment of NPs’ accumulation. The extrapolation from experimental data for laboratory animals to the human organism is implemented by the method of biological similarity. The special algorithm has been created to find the biokinetic constants, which allows to recreate experimental data, and it is based on the method of successive approximation by the criterion of maximum plausibility.The model is released as a computer code on the MATLAB language. There are evaluations of the model’s parameters for two experiments: for single intragastric injection in rat solutions with 35 nm silver NPs and with 8 nm gold NPs. The result of calculations is represented as graph for some organs (liver, kidney and spleen) and it could be considered as acceptable in recreation experimental data. There is also results of calculation for human organism that are got from biokinetic constants by the mechanism of extrapolation. The proposed model can be adapted for others types of metal NPs.

Autoradiography techniques and quantification of drug distribution.

The use of radiolabeled drug compounds offers the most efficient way to quantify the amount of drug and/or drug-derived metabolites in biological samples. Autoradiography is a technique using X- ray film, phosphor imaging plates, beta imaging systems, or photo-nuclear emulsion to visualize molecules or fragments of molecules that have been radioactively labeled, and it has been used to quantify and localize drugs in tissues and cells for decades. Quantitative whole-body autoradiography or autoradioluminography (QWBA) using phosphor imaging technology has revolutionized the conduct of drug distribution studies by providing high resolution images of the spatial distribution and matching tissue concentrations of drug-related radioactivity throughout the body of laboratory animals. This provides tissue-specific pharmacokinetic (PK) compartmental analysis which has been useful in toxicology, pharmacology, and drug disposition/patterns, and to predict human exposure to drugs and metabolites, and also radioactivity, when a human radiolabeled drug study is necessary. Microautoradiography (MARG) is another autoradiographic technique that qualitatively resolves the localization of radiolabeled compounds to the cellular level in a histological preparation. There are several examples in the literature of investigators attempting to obtain drug concentration data from MARG samples; however, there are technical issues which make that problematic. These issues will be discussed. This review will present a synopsis of both techniques and examples of how they have been used for drug research in recent years.

STUDY OF EXOGENOUS MESENCHYMAL STEM CELL MIGRATION AT EXPERIMENT

Objective: to study the migration of mesenchymal stem cells introduced into the body of laboratory animals with induced toxic hepatitis. Materials and Methods: Wistar laboratory rats; CCl 4 -induced toxic hepatitis, mesenchymal stem cells from adipose tissue (isolation, cultivation and coloring by fluorescence PKH 67), the introduction of mesenchymal stem cells in rats, fluorescent microscopy of the organ cryo- images. Results: The analysis of the rats` fluorescence microscopy images revealed the presence of bright yellow-green cell size fluorescence foci (presumably of marked mesenchymal stem cells) caused by greenish cytoplasm autofluorescence and red nucleus fluorescence. It was found that the prevalence of these foci in various organs was differed. The highest density of the foci was observed in spleen and liver in chronic hepatitis. In kidneys, myocardium, lungs, in rare cases, there were isolated foci of bright fluorescence and cases of doubtfully positive cells. Conclusion: The intravenous administration of marked mesenchymal stem cells revealed specific fluorescent foci in the spleen of both the healthy and sick animals and in the liver of the rats with chronic hepatitis. This may be indicative of MSC`s tropism to spleen and injured liver. There was a trend to increase the concentration of the foci from the first to the fifth day of observation.

EFFECT OF INTENSIFICATION OF SELENIUM-PROTECTION PROPERTIES IN LABORATORY ANIMALS DRINKING "FLINT" WATER DUE TO THE INCREASE IN THE COEFFICIENT OF DIFFUSION OF SELENIUM IN ORGANS AND TISSUES

The influence of “flint” water on the development of biochemical processes which cause the accumulation of selenium in the body of laboratory animals has been studied experimentally. A decrease in the bond energy of the molecule of “flint” water with the anion SeO32− in relation to the bond energy of the molecule of ordinary water and an increase in the coefficient of diffusion of this anion in bone and muscular tissues in filtration of “flint” water have been substantiated.