Prostaglandins and myogenic control of tension in lower esophageal sphincter in vitro

E. E. Daniel, J. Crankshaw, S. Sarna

Research output: Contribution to journalArticle

8 Scopus citations

Abstract

Active tension is produced by the lower esophageal sphincter (LES) of North American opossum in vitro by a myogenic mechanism. Strips of LES, but not those from the esophageal body, contracted to prostaglandin (PG)F, stable expoxymethano derivatives of PGH2 and to thromboxane B2. Stable endoperoxides were more than 500 times more potent than PGF. PGI2 and 6-keto PGF were weak relaxants of LES strips. LES strips transformed arachidonic acid into contractile substances. This transformation was prevented by agents which interfere with PG synthesis by inhibiting cyclo-oxygenase [indomethacin (IDM), 5,8,11,14-eicosatetraynoic acid (ETA) or thromboxane synthetase [imidazole]. Tranylcypromine 500 μg/ml also inhibited contractions to arachidonic acid. These agents also reduced muscle tone, so that endogenous PG formation may contribute to active tension in the LES. ETA and IDM increased tone before inhibiting it, and this effect was prevented by prior treatment with ETA or imidazole. There may also be an endogenous PG which inhibits LES tone. The possibility that this may be PGI2 is discussed.

Original languageEnglish (US)
Pages (from-to)629-639
Number of pages11
JournalProstaglandins
Volume17
Issue number4
DOIs
StatePublished - Apr 1979

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Keywords

  • Endoperoxides
  • Esophageal Body
  • Lower Esophageal Sphincter
  • Prostaglandin Receptors

ASJC Scopus subject areas

  • Biochemistry
  • Endocrinology

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