Gamma-Hydroxybutyrate (GHB) elevates Met-enkephalin-Arg6Phe7 (MEAP) levels in the frontal cortex of the male rat brain
(English)Manuscript (preprint) (Other academic)
Gamma-hydroxybutyrate (GHB) has increased in popularity among adolescents during recent years. Predominantly it is used as a recreational drug, but frequently also as an anabolic agent due to its ability of releasing growth hormone. The fact that GHB has been reported to be highly addictive and can cause cognitive deficiencies has become a major concern. In this study, we investigated the impact of GHB treatment in rats on the levels of the endogenous opioid peptides Met-enkephalin-Arg6Phe7 (MEAP) and Dynorphin B (DYNB) in various regions of the brain and on the levels of insulin-like growth factor 1 (IGF-1) in plasma. Furthermore, spontaneous explorative behavior and locomotor activity after GHB administration was analyzed in an Open field (OF). The results demonstrated that treatment with GHB did not affect the parameters that were assessed in the OF, nor did it affect the plasma levels of IGF-1. Regarding the opioid peptide levels, the GHB treated rats demonstrated increased immunoreactive (ir) MEAP but not DYNB levels in the frontal cortex, while no significant alterations were observed in caudate putamen, hypothalamus, nucleus accumbens, amygdala, hippocampus and periaqueductal grey. Moreover, in control rats the levels of ir MEAP and ir DYNB seemed well-balanced in many regions and the peptide levels correlated in amygdala, hippocampus and hypothalamus. However, in the GHB-treated animals no such correlation was observed. In conclusion, GHB treatment created an imbalance regarding the opioids MEAP/DYNB and increased the levels of MEAP significantly in regions of the brain that are of importance for the development of drug dependence.
Research subject Biological Research on Drug Dependence
IdentifiersURN: urn:nbn:se:uu:diva-185422OAI: oai:DiVA.org:uu-185422DiVA: diva2:572266
FunderSwedish Research Council