Prostanoid-induced modulation of neuropeptide Y and noradrenaline release from the rat mesenteric bed

1. A variety of prostanoids were examined for their ability to alter the periarterial nerve stimulation-induced release of noradrenaline (NA) and neuropeptide Y immunoreactive compounds (NPY-ir) from the perfused mesenteric arterial bed of the rat. 2. Periarterial nerve stimulation (16 Hz) increased the overflow of NA, NPY-ir and perfusion pressure. 3. The prostacyclin (PGI2) analogues, carbaPGI2 and cicaprost both produced a concentration-dependent attenuation of the nerve stimulation-induced increase in NA, NPY-ir overflow and perfusion pressure. 4. The prostaglandin (PG) analogue PGE2 attenuated the evoked increase in NPY-ir overflow as well as a modest decrease in NA. 5. PGE1, sulprostone and iloprost attenuated the nerve stimulation-induced increase in NA overflow but not NPY-ir. 6. Neither PGF2alpha nor the thromboxane A2 analogue U46619 altered the evoked increase in NA or NPY-ir overflow. 7. The results support the view that sympathetic co-transmitter release can be differentially modulated by paracrine/autocrine mediators at sympathetic neuroeffector junctions.