| Abstract: | Abstract— —The biosynthesis of immunoreactive prostaglandin E (iPGE) was examined in homogenates of rat superior cervical ganglia and in isolated intact ganglia incubated in vitro. Ganglia homogenates produced iPGE from exogenous arachidonic acid. Prostaglandin synthesis by the homogenates was inhibited by the prostaglandin synthetase inhibitors, eicosatetraynoic acid, indomethacin and sodium meclofenamate and was stimulated by norepinephrine and dopamine. Whole ganglia incubated in Krebs-bicarbonate solution also synthesized iPGE which was released into the incubation bath in a time-dependent manner. As observed in the homogenates, norepinephrine and dopamine enhanced iPGE formation by the intact tissue. Phospholipase A also stimulated iPGE synthesis by the whole ganglia. The effect of phospholipase A was antagonized by dibutyryl cyclic AMP but not by dibutyryl cyclic GMP. The results suggest that neuronally synthesized prostaglandins may be available for modulating adrenergic neuron function and that endogenous neuronal constituents such as catecholamines and cyclic AMP may influence the activity of the prostaglandin synthetase system. |
