Forensic significance of cTnI serum for the detection of terminal myocardial damage in rats (Rattus norvegicus) caused by hyperthermia

To determine whether the biochemical marker cTnI with circulating value has forensic significance in the detection of myocardial damage in rats in experimental conditions of hyperthermia by exposure to water temperatures of 41 °C. The study was conducted on 24 adult Wistar rats that were divided into two experimental groups, depending on water temperature exposure of 37 °C (KG, n = 8) and 41 °C (G41, n = 16). Depending on the length of time of exposure to water temperatures of 41 °C are further divided into G41-AM (20 min of exposure), G41-PM (exposure until death). Blood for analysis of the concentration of cardiac troponin I (cTnI) was taken before the experiment and after the expiration of the given duration of the experiment of 20 min or death. The concentration of cTnI was determined in serum by ELISA method. The level of statistical significance was, p < 0.05. Eight rats of the G41 group achieved a core temperature that is the threshold for heat stroke. The median survival time for group G41 was 175.5 min. The median cTnI was 358.64 for group KG 37. The control group of rats had significantly lower serum cTnI values compared to G41. Examination of the length of exposure to appropriate temperatures led to significant increases in cTnI in the serum; A significant difference was found in the values of cTnI KG37 and G41-PM. CTnI values differed significantly in the G41-AM and G41-PM groups. In G 41 °C, a positive correlation was found between serum cTnI values and body temperature measured in fatal outcome. CTnI with their changes in serum concentration indicate exposure to high water temperature.