Demakova N.V. , Krasnova M.V., Plisko G.A., Semivelichenko E.D., Ivkin D.Yu., Okovityy S.V. Impedansometry as an estimating method of tertiary endpoint in experimental modeling of alimentary impairments. Laboratory Animals for Science. 2021; 2. https://doi.org/10.29296/2618723X-2021-02-07
In preclinical practice, methods for assessing the body composition of laboratory animals are used, such as: computerized tomography, quantitative magnetic resonance, dual-energy X-ray absorptiometry, gravimetric method, bioimpedance spectroscopy method (hereinafter referred to as bioimpedansometry, BIS). These methods have several strengths and shortcomings. The most controversial from the point of view of efficiency is the gravimetric method, which requires necropsy of the animal with the isolation of the entire pool of adipose tissue. If it is necessary to measure the mass fraction of fat at several points of the study, an increase in the number of experimental animals is required a multiple of the number of points, which contradicts the bioethical principle of Reduction. The purpose of this article was to assess the capabilities of the bioimpedance measurement method in preclinical studies, including those requiring experiments using models of alimentary disorders. Experimental modeling of alimentary obesity in laboratory animals (male Brown Norway rats) was carried out with further comparative assessment using bioimpedance spectroscopy of the following indicators: volume of total body water, intra- and extracellular fluid, fat free mass, fat mass (including through mass fraction), body mass index. In parallel, data on the total weight of animals obtained by weighing them are presented. In the experiment, we used the ImpediVet BIS1 device for measuring bioimpedance, manufactured in the USA, with 4 electrodes equipped with needles for insertion in the nose, between the ears, at the base of the tail and in the coccygeal zone. Bioimpedance measurements were performed on anesthetized animals. The results of our own experiment, as well as data from literary sources, allow us to recommend the bioimpedance method as reproducible, it has proven itself well in tests on rodents. However, the capabilities of both the method and the device allow measurements on large laboratory animals such as dogs, pigs, monkeys, horses and cattle. The method is minimally invasive, which meets the bioethical principles of 3R, including the part concerning the principle of Refinement (Improvement of technology for working with laboratory animals).
N.V. Demakova – carried out the experiment, tried out the bioimpedance spectroscopy method, analysed the data, wrote the manuscript, translated the parts of the manuscript into English, corrected the text in accordance with the requirements of the journal
M.V. Krasnova – carried out the experiment, processed raw data
G.A. Plisko – took part in carrying out the experiment, animal care, prepared hypercaloric feed
E.D. Semivelichenko – took part in carrying out the experiment, caring for animals, preparation of hypercaloric feed.
D.Yu. Ivkin – worked with literary sources, summarized the material, wrote the manuscript, approved the final version of the manuscript for publication
S.V. Okovityi – worked with literary sources, summarized the material, edited the text of the manuscript, approved the final version of the manuscript for publication.
The authors declare that there is no conflict of interest.