Threshold of Gamma-Hydroxybutyric Acid

by Luke Probasco
Faculty advisor: Dr. Tim Ehler

Gamma-Hydroxybutyric acid (GHB) is naturally produced in the body and can be found in the central nervous system (CNS) and peripheral tissues. GHB is a strong CNS depressant due to its interaction with gamma-aminobutyric acid (GABAb ) receptors in addition to its reaction with a specific GHB-receptor. GHB also alters dopamine transmission. GHB is a Scheduled I controlled substance as well as a Schedule III controlled substance (sold under trademark Xyrem).

Gamma-Butyrolactone (GBL) and GHB are always in equilibrium within our bodies. Due to this, GBL is also becoming more abused because once GBL is ingested it is biotransformed to GHB. The natural levels of GHB in our bodies can range from 0.00µg/mL to 3.08µg/mL. Currently the cutoff for determining if a case is a drug facilitated sexual assault (DFSA) is 10µg/mL.

Over J-Term I worked at the Iowa Division of Criminal Investigation (DCI) in Ankeny, Iowa. During this time I worked on replicating a study and adding another evaluation method to determine the proper threshold for GHB levels in the human body. I was not able to conclude if the current threshold is a good indication because I ran out of standard GBL, and the GBL that was ordered got lost in the mail. At the time, I was working on creating a calibration curve to measure my samples. I plan on finishing this study in the fall.