Comparison of the effects of two methods of euthanasia on post mortem changes in rats: histopathological and molecular findings

AbstractPostmortem changes (PMCs) not only affect the results of experimental studies, but also determine postmortem intervals in forensic sciences. The present study aimed to assess the effects of two methods of laboratory animals ’ euthanasia on PMCs in rats. In this experimental study, 10 female rats were randomly assigned to two equal groups and were euthanized using the inhalation of CO2 (gas-treated group) or over-dose intramuscular injection of ketamine/xylazine (drug-treated group). Kidney and liver tissue samples were collected at baseline and 2, 4, 6, 8, 10, 12, 24, and 48  h after euthanasia and were subjected to histopathological examinations. The expression of liver-specific microRNA-122 (miR-122) was also assessed in each time point via a SYBR green real-time polymerase chain reaction (PCR) assay. Finally, miR-122 target genes and related functional pathways were identified through bioinformatics analysis. The progression of PMCs in the drug-treated group was faster than the gas-treated group. The expression of miR-122 was significantly (P <  0.0001) upregulated in the drug-treated group at 4, 10, and 24 h in comparison to the gas-treated group; however, it was downregulated at 6, 8, and 48 h after euthanasia. The biosynthesis of amino acids, glycolysis/gluconeogenesis, and carbon metabolism as well as the glucagon, Hedgehog, cGMP-P KG, and neurotrophin signaling pathways were identified as the significant pathways related to miR-122 target genes. Th...
Source: Comparative Clinical Pathology - Category: Pathology Source Type: research