The Influence of Morphine on Cerebral 5-HT2A Availability in Dogs: a SPECT Study

Journal of Nuclear Medicine

Luc Duchateau¹  Simon T. Vermeire¹  Stanislas U. Sys¹  Sylvia Van Dorpe¹  Ingeborgh E. Polis¹  Antita M. Adriaens¹  Tim Waelbers¹  Kathelijne Peremans¹  Jos L. Eersels¹  Bart De Spiegeleer¹ 

关键词: serotonin (5-HT);    5-HT_2A;    morphine;    SPECT;    frontal cortex;   

DOI  :  10.2967/jnumed.112.103796

学科分类：医学（综合）

来源: Society of Nuclear Medicine

【 摘 要 】

The opioid and serotonergic systems are closely involved in pain processing and mood disorders. The aim of this study was to assess the influence of systemic morphine on cerebral serotonin 2A receptor (5-HT2A) binding in dogs using SPECT with the 5-HT2A radioligand 123I-5I-R91150. Methods: 5-HT2A binding was estimated with and without morphine pretreatment in 8 dogs. The 5-HT2A binding indices in the frontal, parietal, temporal, and occipital cortex and in the subcortical region were obtained by semiquantification. Results: A significantly decreased 5-HT2A binding index was found in the morphine group for the right (morphine, 1.41 ± 0.06; control, 1.52 ± 0.10) and left (morphine, 1.44 ± 0.08; control, 1.55 ± 0.11) frontal cortices, with P = 0.012 and P = 0.040, respectively. No significant differences were noted for the other regions. Conclusion: Morphine decreased the frontocortical 5-HT2A availability, confirming an interaction between the 5-HTergic and the opioid systems. Whether this interaction is caused by decreased receptor density due to direct internalization or is the result of indirect actions, such as increased endogenous serotonin release, remains to be elucidated.

【 授权许可】

Unknown