A Study On The Myoglobin Redox Of Pig Skeletal Muscle And Post-Mortem Interval By Uv-Vis Spectrophotometric Technique

Myoglobin is a protein widely found in human and mammalian skeletal muscle cells. Studies have shown that the myoglobin measured by western blotting has a good correlation with post-mortem interval (PMI), but the western blotting method is cumbersome and time-consuming, and is not suitable for rapid and accurate analysis of multiple samples. To this end, this study tried to use UV- Vis spectrophotometry (Krzywicki's method and Viriyarattanasak's method) to determine the content of myoglobin redox (DeoMb, OxyMb, MetMb) in skeletal muscle at different times after death, and to explore its relationship with PMI and ADH. In this experiment, the left hind kg muscle of the pig was kept in a natural environment. Skeletal muscle were randomly extracted at 2 h, 8 h, 16 h, 24 h, 32 h, 40 h, 48 h, 72 h, 96 h, 120 h, 144 h, 168 h after the pig's death, weighed, pH measured, and then made into a homogenate dipping solution. The myoglobin redox in the skeletal muscle was measured by UV-Vis spectrophotometry, and its changes with PMI and ADH were explored, which study the correlation with PMI and ADH respectively. The results showed that the skeletal muscle loss, pH, and content of myoglobin redox varied with PMI and ADH; the loss and pH are highly correlated with PMI (or ADH) (R2=0.84-0.91), and the fitting relationship between the two and ADH is better; the correlation between myoglobin redox and PMI (or ADH) under the two UV-Vis spectrophotometry methods is weak (R2=0.03-0.28), and the curve fitting relationship is poor. Unfortunately, we concluded that UV-Vis spectrophotometry determination of myoglobin redox in cadaver muscles cannot appear to be a reliable method for PMI estimation. However, measuring muscle loss and pH may be an potential method to estimate PMI.