Stimulatory (EP1 and EP3) and inhibitory (EP2) prostaglandin E2 receptors in isolated ileal smooth muscle cells.
Isolated smooth muscle cells from the circular layer of pig and guinea-pig ileum were used to study the effect of prostaglandin E2 (PGE2) and three PGE2 receptor (EP) agonists; iloprost (EP1), butaprost (EP2) and enprostil (EP3). In pig cells, PGE2 and enprostil induced cell contraction (22.1 and 21.5% shortening of cell length, obtained at 10 nM for PGE2 and 1 nM for enprostil, respectively). Iloprost and butaprost had no contractile effect. However, the cholecystokinin octapeptide (CCK-8; 10 nM)-induced contraction was inhibited when cells were preincubated with iloprost or butaprost. In guinea-pig cells, PGE2, butaprost and iloprost induced cell contraction, whereas enprostil had no effect (23.1% for 10 nM PGE2, 22.8% for 1 nM butaprost and 22.6% for 10 nM iloprost). Preincubation with SC19220 (EP1 antagonist) inhibited the PGE2-, butaprost- and iloprost-induced contractions. When the contractile effect of PGE2, butaprost and iloprost was inhibited by addition of SC19220, these agents inhibited the cell contraction induced by CCK-8 (1 nM). Smooth muscle cells from guinea-pig and pig ileum express two PGE2 receptor subtypes that induce opposite effect. EP1 and EP3 receptors mediate cell contraction in guinea-pig and pig, respectively, whereas EP2 receptors mediate cell relaxation in both species.
Botella
A
A
Department of Pharmacology, INRA, Toulouse, France.
Delvaux
M
M
Fioramonti
J
J
Frexinos
J
J
Bueno
L
L
D000527:Alprostadil / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000494:pharmacology; D000818:Animals; D012531:Dibenz(b,f)(1,4)oxazepine-10(11H)-carboxylic acid, 8-chloro-, 2-acetylhydrazide / Q000494:pharmacology; D015232:Dinoprostone / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000494:pharmacology; D016620:Enprostil / Q000037:antagonists & inhibitors / Q000494:pharmacology; D006168:Guinea Pigs; D007082:Ileum / Q000166:cytology / Q000187:drug effects; D016285:Iloprost / Q000037:antagonists & inhibitors / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D011459:Prostaglandins E, Synthetic / Q000037:antagonists & inhibitors / Q000494:pharmacology; D011982:Receptors, Prostaglandin / Q000187:drug effects* / Q000302:isolation & purification; D012844:Sincalide / Q000494:pharmacology; D013552:Swine
D011459:Prostaglandins E, Synthetic; D011982:Receptors, Prostaglandin; D012531:Dibenz(b,f)(1,4)oxazepine-10(11H)-carboxylic acid, 8-chloro-, 2-acetylhydrazide; D000527:Alprostadil; C048491:butaprost; D016620:Enprostil; D016285:Iloprost; D015232:Dinoprostone; D012844:Sincalide