Signaling pathways leading to prostaglandin E2 production by rat cerebral frontal cortex

In this paper, we have determined the effect of both muscarinic acetylcholine receptor (mAChR) and exogenous prostaglandin E2 (PGE2) on PGE2 production and cyclooxygenases (COX) mRNA gene expression on rat cerebral frontal cortex. Carbachol and PGE2 increase endogenous PGE2 production and the COX-1 mRNA levels by activation of PLA2s. The COX-1 and COX-2 activity participated in the production of PGE2 triggered by exogenous PGE2. While in carbachol-PGE2 only COX-1 activity is affected. The specific inhibition of PGE2 receptor was able to impair the increase of endogenous PGE2 production triggered by both carbachol and exogenous PGE2. These results suggest that carbachol-activation mAChR increased PGE2 production that in turn interacting with its own receptor triggers an additional production of PGE2. Both mechanisms appear to occur by using PLA2 signaling system. This data should be able to contribute to understand the involvement of PGE2 in normal brain function and its participation in neuroinflammatory processes.