title: [Contribution of prostaglandins to the activity of guinea-pig phrenic and chicken esophageal parasympathetic nerves].
abstract: In order to clarify the role of prostaglandins (PGs) in the activity of cholinergic neurones other than the ileal myenteric plexus, the effects of indomethacin (IND) and PGE2 on the contractile responses and the release of acetylcholine (ACh) induced by electrical stimulation were investigated in isolated guinea-pig phrenic nerve-diaphragm and chicken parasympathetically innervated oesophagus preparations. In the guinea-pig phrenic nerve-diaphragm preparations, IND at 56 microM did not affect the twitch responses induced by direct or indirect electrical stimulation. PGE2 at 1 microgram/ml augmented the twitch responses induced by direct or indirect stimulation of submaximal, but not of supramaximal intensity. The amounts of ACh released from the phrenic nerve by electrical stimulation were unaffected by IND (56 microM). PGE2 (0.01-1 microgram/ml) inhibited the ACh release by the nerve stimulation of high frequency (50 Hz) in a concentration-dependent manner. The inhibitory effect of PGE2 was less clear on the ACh release by lower frequency (1 Hz). Neither IND nor PGE2 affected the ACh release induced by 40 mM-K+. In the chicken parasympathetically innervated oesophagus preparation, IND (2.8-5.6 5.6 microM) augmented the twitch responses induced by the nerve stimulation at a frequency of 0.017 Hz, but not those produced by train pulse (5 sec at a frequency of 1 or 10 Hz). This augmentation was reversed by the application of PGE2 at 10 ng/ml. PGE2 at 10 ng/ml produced a transient inhibition of the twitch responses induced by 0.017 Hz or train pulses.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D002645:Chickens; D015232:Dinoprostone; D004947:Esophagus / Q000294:innervation*; D006168:Guinea Pigs; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D010275:Parasympathetic Nervous System / Q000502:physiology*; D010791:Phrenic Nerve / Q000502:physiology*; D011453:Prostaglandins / Q000502:physiology*; D011458:Prostaglandins E / Q000494:pharmacology; D009435:Synaptic Transmission / Q000187:drug effects
chemical_list: D011453:Prostaglandins; D011458:Prostaglandins E; D015232:Dinoprostone; D000109:Acetylcholine; D007213:Indomethacin