INTRODUCTION Rigor mortis is a postmortem change resulting in the stiffening of the body muscles due to chemical changes in their myofibrils. Rigor mortis helps in estimating the time since death as well to ascertain if the body had been moved after death.[1]
What is the role of adenosine triphosphate in rigor mortis?
Adenosine triphosphate (ATP) is a necessary component in the relaxation of the myosin filaments of normal muscle. Rigor mortis commences when the rate of re-synthesis of ATP is less than its degradation. In the early hours after clinical death, muscle glycogen fuels the cycle of hydrolysis and re-synthesis of ATP.
How long does it take for rigor to take hold?
First noticed in the small muscle groups such as in the hands and face, rigor can take hold within 3 to 4 h and normally extends across the large muscle groups also within the first 12 h after death, causing the entire body to become stiff.
What happens to myofilaments after rigor mortis peak?
In rigor mortis myosin heads continue binding with the active sites of actin proteins via adenosine diphosphate (ADP), and the muscle is unable to relax until further enzyme activity degrades the complex. Decomposition of the myofilaments occurs 48 to 60 hours after the peak of rigor mortis, which occurs approximately 13 hours after death.
What is the function of myosin heads in rigor mortis?
In rigor mortis myosin heads continue binding with the active sites of actin proteins via adenosine diphosphate (ADP), and the muscle is unable to relax until further enzyme activity degrades the complex.
Why does the body enter rigor mortis after glycogen depletion?
When oxygen is no longer present, the body may continue to produce ATP via anaerobic glycolysis. When the body’s glycogen is depleted, the ATP concentration diminishes, and the body enters rigor mortis because it is unable to break those bridges.
