The release of prostaglandin E1 from the rat phrenic nerve-diaphragm preparation.

1. The release of prostaglandin E(1) from the rat phrenic nerve-diaphragm preparation during tetanic contraction of the muscle in response to nerve stimulation is reported. Tentative identification of the prostaglandin depended on solvent extraction column and thin-layer chromatography and parallel biological assay.2. Polar lipid substances were released from the preparation in the absence of nerve stimulation by (+)-tubocurarine and noradrenaline.3. The output on nerve stimulation was not abolished by (+)-tubocurarine, hemicholinium, bretylium or phenoxybenzamine added to the bath.4. The possible origin of these prostaglandins is discussed.