Imaging Brain Phospholipase A2 Activation in Awake Rats in Response to the 5-HT2A/2C Agonist (±)2,5-Dimethoxy-4-Iodophenyl-2-Aminopropane (DOI)
Neuropsychopharmacology February 1, 2003 Y. Qu, Lisa Chang, J. Klaff et al.
In unanesthetized adult rats, an injection of the 5-HT2A/2C receptor agonist DOI (2.5 mg/kg intraperitoneally) caused widespread increases of about 60% in the incorporation coefficient of arachidonic acid from blood into brain, particularly in neocortical regions with high densities of 5-HT2A receptors. These increases were entirely blocked by chronic pretreatment with the 5-HT2 receptor antagonist mianserin. The findings suggest that the 5-HT2 syndrome involves widespread activation of phospholipase A2 via 5-HT2A receptors, leading to release of the second messenger arachidonic acid, and that chronic mianserin prevents this activation.