The content of lactate in muscle tissue of different types in the early post-mortal period.

Unlabelled: It's known from the basics of clinical biochemistry and pathophysiology, lactate is the end product of anaerobic glycolysis. During exercise lactate leaves the muscles and is converted by the liver into pyruvate or metabolized by brain tissue and heart muscle. The level of lactate in muscle tissue from the standpoint of forensic examination to determine the age of death (PDC) during the early postmortem period (PMP) has not been previously studied.

Aim: The aim of the study was to study the postmortem patterns of lactate content in muscle tissue (MT) of various types to increase the accuracy of determining the age of death.

Materials And Methods: Determination of lactate content was performed in homogenates of myocardial muscles, esophagus, diaphragm and intercostal muscles in early PMP (3-13 hours after death) in 30 human corpses. MT collection was performed in sectional biopsy using special tools, preparation of MT homogenates - according to standard methods with subsequent determination of lactate content in MT homogenates by enzymatic photometric method.

Results: Analysis of postmortem changes in lactate content in MT, depending on the time periods of the prescription of death coming (PDC)revealed that after 3 hours. since the onset of death, the highest content was in the intercostal muscles, the lowest - in the MT of the esophagus (respectively - (6,847 ± 0,042) mmol/g and (3,266 ± 0,031) mmol/g, p<0,001. in MT of different types was characterized by fluctuations with increasing terms of PDC, in addition, our time series became the basis for substantiating the quantitative time dependences and construction of appropriate nomograms for forensic diagnosis of PDC by lactate content in MT.

Conclusions: t is proved that the lactate content naturally (and nonlinearly) changed in all studied homogenates of MT, but the initial and final level of lactate content differs depending on the type of MT. In addition, the dynamics of changes in lactate content in the time period 3÷13 hours. from the moment of death, depending on the type of MT also varies. The quantitative analytical and graphical dependences of the change in the lactate content in MT in the early PMP revealed in the study allowed to substantiate the corresponding nomograms.