The modulatory effects of prostaglandins on both excitatory and inhibitory non-adrenergic non-choIinergic neurotransrnission in guinea-pig airways

Johansson -Rydberg , I. G. M., Andersson , R. G. G. & Grundström , N. 1 992 , The modulatory effects of prostaglandins on both excitatory and inhibitory non-adrenergic non-cholinergic neurotransmission in guinea-pig airways. Acta Physiol Scand 144 , 439444. Received 28 August 1 991 , accepted 20 November 1991. ISSN 0001–6772. Department of Pharmacology, University Hospital of Linkoping, Sweden. Guinea-pig trachea and bronchi were used to investigate the effects of indomethacin and prostaglandin E₂ (PGE₂) on non-adrenergic non-cholinergic excitatory (e-NANC) and inhibitory (i-NANC) neurotransmission evoked by electrical field stimulation. Indomethacin potentiated e-NANC responses in bronchi with intact epithelium but had no effect on epithelium-denuded preparations. Inhibitory NANC responses were increased by indomethacin independent of the epithelium. Both i-NANC and e-NANC neurotransmission were suppressed by PGE₂ in a dose-dependent manner. These results indicate that endogenous prostaglandins (e.g. PGE₂) generated from the epithelium have an inhibitory effect on i-NANC and e-NANC nerve responses in airways. The epithelium is presumably not the only source for generation of prostaglandins that are involved in i-NANC neurotransmission.