IMPACT OF THE ENVIRONMENTAL TEMPERATURE ON THE CHRONOLOGICAL SEQUENCES OF POSTMORTEM CHANGES IN HEPATIC AND RENAL TISSUES OF ALBINO MICE (Mus Musculus)

The current study was carried out to detect the effect of the environmental temperature on the postmortem histological and molecular changes and their synchrony with the time since death (TSD). A total of 30 male, albino mice were sacrificed by decapitation. Carcasses have been divided into two groups, 15 in each group. The first group left at room temperature (25 +/- 3 degrees C) and the second one kept in the refrigerator (4 degrees C). Tissue specimens from livers and kidneys have been taken at a definite time interval (0, 6, 12, 24, and 36 hours after death). Tissue specimens were processed into paraffine-embedded sections stained with Hematoxylin and. Eosin to investigate the histological changes. Liver and kidney taken directly after death from both animal groups showed the normal structures. However, time-dependent degenerative changes have been seen in both organs throughout the postmortem time periods (6, 12, 24, and 36 hours after death). These changes influenced both the tissue architectural configuration and the cellular integrity. The cellular changes involved cytoplasmic and nuclear elements. The cytoplasmic changes ranged from partial to complete vacuolation. The nuclear changes included pyknosis, karyorrhexis, and karyolysis. Preserving animal carcasses at a lower temperature delayed the progression of these changes. Also, the molecular findings showed that the integrity of DNA from liver and kidney either kept at room temperature or in refrigerator (4 degrees C) was lost in a time-dependent manner, Yet, DNA degradation occurred at a slower rate at low temperatures. In conclusion, it was evident that holding the carcasses of mice at lower temperatures may delay degenerative changes and DNA degradation. Moreover, the association of both histological and molecular testing may support each other in the determination of the TSD, especially in the earlier postmortem periods.