Endogenous gamma-hydroxybutyric acid levels in postmortem blood

Area of Science:

• Forensic Toxicology
• Biochemistry

Background:

• Endogenous gamma-hydroxybutyric acid (GHB) is a naturally occurring substance in the body.
• Understanding factors affecting GHB levels in postmortem blood is crucial for accurate toxicological interpretation.

Purpose of the Study:

• To investigate the impact of postmortem interval and cold storage duration on endogenous GHB concentrations in blood.
• To differentiate GHB levels attributed to postmortem changes versus sample storage conditions.

Main Methods:

• Analysis of 43 autopsy blood samples from non-GHB users with varying postmortem intervals (8-132 hours).
• Blood samples stored at 4°C (1 day to 15 months) and -20°C (10 days to 7 months).
• Quantification of GHB using headspace gas chromatography after conversion to gamma-butyrolactone.

Main Results:

• A positive correlation (r=0.571) was found between blood GHB concentration and postmortem interval.
• No significant correlation was observed between GHB levels and storage duration at 4°C.
• GHB concentrations were comparable in samples stored at 4°C and -20°C for similar periods.

Conclusions:

• Elevated endogenous GHB in postmortem blood is primarily influenced by the postmortem interval.
• GHB levels are not significantly altered by storage at 4°C for extended periods.
• Bacterial glycolysis is a potential contributor to endogenous GHB formation after death.