Role of Cardiac Troponin I in Case of Death Time EstimationAn in Vitro Study

Abstract

Background- Beta blockers are used for treating hypertension but few of them when taken in overdose
can be fatal. Acebutolol is one such beta-adrenoreceptor blocking agent that is considered one of the most
toxic beta blockers when taking overdose. Determination of postmortem interval is a common practice in
medicolegal investigation.
Objective: The present study was conducted to investigate the degradation pattern of cTnI with respect to
time.
Materials And Methods: Group 1 were anesthetized with Sodium pentobarbital (40 IP). The chest cavity
was then quickly opened, and the heart was excised out. Group 2 (Asphxial Death) were sacrificed by
clamping a tracheostomy tube. Group 3 (Acebutolol Death) were sacrificed by giving an oral lethal dose of
Acebutolol(6620mg/kg). Incubation at 28º C for different time interval (0 hrs, 6 hrs, 12 hrs, 24hrs, 48 hrs,
72 hrs, 96 hrs and 100 hrs). The heart was then isolated and freezed at-80ºC.The extraction of protein from
tissue was optimized so as to stop or minimize the degradation of protein during the extraction process. The
conventional method was used for extraction with slight modifications in the extraction buffer and an added
step of carrying every step of the extraction process at low temperature (1-4ºC)
Results- The data clearly established that the degradation pattern of cTnI is different for all the three groupsControl, Acebutolol and Asphyxia. In case of Acebutolol the degradation of cTnI into its molecular fragments
is at a much faster rate when compared to the Control and Asphyxia groups, The difference in degradation
of cTnI is because Acebutolol is highly cardiotoxic, and its effect on cardiac tissues is high and immediate.
Conclusion- The degradation of intact cTnI into smaller molecular fragments is also dependent upon
temperature. In order to know more about the measurement of cTnI fragmentation for the determination of
the postmortem interval, further investigations are necessary to understand more about the cTnI degradation
pattern.