ABSTRACT
Objective T o explore the relationship betw een the change rules of volatile organic com pounds (V O C s) in rat m uscle and postm ortem interval (PM I). Methods A total of 120 healthy rats w ere divided random ly into 12 groups (10 for each group). A fter the rats w ere sacrificed by cervical dislocation, the bodies w ere kept at (25±1)℃. R at m uscle sam ples w ere separately obtained at 12 PM I points, including 0, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 d. T he V O C s in rat m uscles w ere collected, detected and ana-lyzed by headspace solid-phase m icroextraction (H S-SPM E ) coupled to gas chrom atography-m ass spec-trom eter (G C-M S ). Results In total, 15 species of V O C s w ere identified, including 9 arom atic com-pounds, 3 sulfur com pounds, 2 aliphatic acids and 1 heterocyclic com pound. T he species of V O C s in-creased w ith PM I: no species w ere detected w ithin 1 day, 3 species w ere detected on day 2, 9 on day 3, 11 on day 4, 14 from day 5 to 7, and 15 from day 8 to 10. T otal peak area of 15 species of V O C s w as significantly correlated to PM I (adjusted R2=0.15-0.96): the regression function w as y=-17.05 x2+164.36 x-246.36 (adjusted R2=0.96) from day 2 to 5, and y=2.24 x+101.13 (adjusted R2=0.97) from day 6 to 10. Conclusion T he change rules of V O C s in rat m uscle are helpful for PM I estim ation.
ABSTRACT
Objective T o analyze the relationship am ong electrical conductivity (E C ), total volatile basic nitrogen (T V B-N ), w hich is an index of decom position rate for m eat production, and postm ortem inter-val (PM I). T o explore the feasibility of E C as an index of cadaveric skeletal m uscle decom position rate and lay the foundation for PM I estim ation. Methods H ealthy Sprague-D aw ley rats w ere sacrificed by cervical vertebrae dislocation and kept at 28℃. M uscle of rear lim bs w as rem oved at different PM I, ho-m ogenized in deionized w ater and then skeletal extraction liquid of m ass concentration 0.1 g/m L w as prepared. E C and T V B-N of extraction liquid w ere separately determ ined. T he correlation betw een E C (x1) and T V B-N (x2) w as analyzed, and their regression function w as established. T he relationship be-tw een PM I (y) and these tw o param eters w ere studied, and their regression functions w ere separately established. Results T he change trends of E C and T V B-N of skeletal extraction liquid at different PM I w ere alm ost the sam e, and there w as a linear positive correlation betw een them . T he regression equation w as x2=0.14 x1-164.91 (R2=0.982). E C and T V B-N of skeletal m uscle changed significantly w ith PM I, and the regression functions w ere y=19.38 x13-370.68 x12+2526.03 x1-717.06 (R2=0.994), and y=2.56 x23-48.39 x22+330.60 x2-255.04 (R2=0.997), respectively. Conclusion E C and T V B-N of rat postm ortem skeletal m uscle show sim ilar change trends, w hich can be used as an index for decom position rate of cadaveric skeletal m uscle and provide a m ethod for further study of late PM I estim ation.
ABSTRACT
Objective To investigate correlation between the changes of oxidation reduction potential (ORP ) values of heart blood in rabbits after death and postm ortem interval (PMI) at different temperatures. Meth-ods Forty-eight rabbits were random ly divided into 6 groups and sacrificed by air em bolism . Blood sam-ples were taken from the right ventricle of each rabbit and stored at different temperatures of 10, 15, 20, 25, 30and 35℃, respectively. Every 4 hours from 0h to 132 hpostm ortem , the ORP values of the blood samples were measured at different intervals by PB-21 electrochem ical analyzer. The curvilinear regres-sion equation was established by SPSS 17.0software. The surface equation and 3D surface diagram were established by MATL A B7.10.0software. Results The ORP values at different temperatures of heart blood in rabbits were highly correlated with the PMI. The ORP values rised obviously when the temper-ature was high and rised slowly when the temperature was low. The surface equation and 3D surface diagram were obtained. Conclusion The surface equation and 3D surface diagram of ORP values and PMI may be used for PMI estimation at different temperatures.