Dynamics of postmortem changes in carcasses of dead laboratory animals

Ya.A. Gushchin, Head of the Department of laboratory diagnostics, ORCID 0000-0002-7656-991X
E.V. Belyaeva, Head of the Laboratory of histology and pathomorphology, ORCID 0000-0003-1299-0200
J.Yu. Ustenko, Pathomorphologist, Department of histology and pathomorphology, ORCID 0000-0003-1299-0200

Research and manufacturing company «Home оf Pharmacy», 188663, Russia, Leningrad oblast, Vsevolozhskiy district, Kuzmolovskiy t.s., Zavodskaya st. 3-245
Е-mail: guschin.ya@doclinika.ru



Patho-morphological study of organs and tissues it is an important tool in modern biomedical research. It is considered an integral part of the development, testing and safety assessment of new medicinal substances. However, due to various reasons, it is not always possible to perform an autopsy immediately, and there is a necessity to preserve the corpses for further study. The purpose of the study was to evaluate the dynamics of postmortem changes in laboratory animal’s corpses (mice, rats and rabbits), to identify optimal conditions for the storage (+16–22, +2–4 or -18–22°C), and to determine the timeframe for postponing necropsy without loss of informativeness (from 12 to 72 hours and 2 months in case of freezing). Post-mortem changes were analyzed macroscopically and microscopically using a semi-quantitative assessment. It has been found that changes occur faster when corpses stored at room temperature. Besides, the size of animals also affects on the rate of decomposition. So in mice, with their small body volume, autolysis processes begin to develop in 18 hours after death, and by 72 hours they become catastrophic. At the same time, in larger animals – rats and rabbits, the development of post-mortem changes is slightly delayed, so after three days stored at a temperature of +16–22°C, macroscopic diagnosis was still possible. The decomposition processes can be significantly slowed down by placing the corpses in a refrigerating chamber with a temperature of +2–4°C as soon as possible. But although for macroscopic analysis, the corpses of all the studied animal species are preserved two and, albeit somewhat worse, three days after death, the sampling of tissues for histological examination should be carried out within 48 hours from the moment of death. Storage of corpses at a temperature of -18–22°C is an extreme measure, because, although the macroscopic structure of organs does not change in any way, the microstructure of tissues is disrupted, due to cryogenic damage.

Thus, as a result of the study, the optimal time for the possible pathomorphological examination of the laboratory animals corpses after their unplanned death without loss or with minimal loss of informativeness under various storage conditions was revealed.

Full text avaliable in Russain only 

Author’s Contribution

Gushchin Ya.A. – idea, concept and design of the study, writing and editing the text of the article, working with literary sources.
Belyaeva E.V. – conducting a histological examination, collecting and organizing material, drawing up tables.
Ustenko Zh.Yu. – carrying out necropsy, a description of the results of a macroscopic examination.


Conflict of interest

Авторы заявляют об отсутствии конфликта интересов.


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