Inhibitory effect of beta3-adrenoceptor agonist in lower esophageal sphincter smooth muscle: in vitro studies.
We investigated the effects of (R,R)-5-[2-[2-3-chlorophenyl)-2-hydroxyethyl] - amino]propyl] - 1,3 - benzodioxole - 2, 2 - dicarboxylate (CL 316243) (a typical beta3-agonist) on the spontaneously tonic smooth muscle of the lower esophageal sphincter (LES). Studies were carried out in smooth muscle strips and smooth muscle cells (SMCs) of opossum LES. Isometric tension was recorded in the basal state and after CL 316243, and before and after beta3-antagonist (S)-N-[4-[2-[[3-[-(acetamidomethyl)phenoxy]-2-hydroxypropyl]amino]ethyl]phenyl]benzenesulfonamide (L 748337) and nonselective antagonist propranolol. In some experiments, the effects of nonadrenergic noncholinergic (NANC) nerve activation by electrical field stimulation (EFS) were also examined. The effects of CL 316243 were compared with those of nonselective beta-agonist isoproterenol. CL 316243 caused a concentration-dependent relaxation of the LES smooth muscle. The relaxant action of CL 316243 was determined to be directly at the smooth muscle because it remained unmodified by the neurotoxin tetrodotoxin and other neurohumoral antagonists, and also was observed in the SMCs. L 748337 selectively antagonized the relaxant effect of CL 316243 and, conversely, had no significant effect on the inhibitory actions of isoproterenol. CL 316243 (1 x 10(-8) M) caused an augmentation of NANC relaxation in the LES. Another beta3-agonist, (S)-4-[hydroxy-3-phenoxy-propylamino-ethoxy]-N-(2-methoxyethyl)-phenoxyacetamide (ZD 7114), also caused concentration-dependent full relaxation of the LES that was selectively antagonized by beta3-anatagonist 3-(2-ethylphenoxy)-1-[(1S)1,2,3,4-tetrahydronaphth-1-ylaminol]-(2S)-2-propanol oxalate (SR 59230A). These studies defined the effects of characteristic inhibitory beta3-adrenoceptors in the spontaneously tonic LES smooth muscle and suggested a potential therapeutic role in the esophageal motility disorders characterized by hypertensive LES.
Sarma
D N K
DN
Department of Medicine, Division of Gastroenterology and Hepatology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
Banwait
Kuldip
K
Basak
Ashim
A
DiMarino
Anthony J
AJ
Rattan
Satish
S
D058667:Adrenergic beta-3 Receptor Agonists; D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000627:Aminophenols / Q000494:pharmacology; D000818:Animals; D001341:Autonomic Nervous System / Q000187:drug effects; D004149:Dioxoles / Q000494:pharmacology; D004558:Electric Stimulation; D004943:Esophagogastric Junction / Q000187:drug effects*; D066298:In Vitro Techniques; D007537:Isometric Contraction / Q000187:drug effects; D007545:Isoproterenol / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D009893:Opossums / Q000502:physiology*; D010642:Phenoxyacetates / Q000494:pharmacology; D050198:Phenoxypropanolamines; D011412:Propanolamines / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D013449:Sulfonamides / Q000494:pharmacology
C097869:3-(2-ethylphenoxy)-1-(1,2,3,4-tetrahydronaphth-1-ylamino)-2-propanol oxalate; D058667:Adrenergic beta-3 Receptor Agonists; D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D000627:Aminophenols; D004149:Dioxoles; C120576:L 748,337; D010642:Phenoxyacetates; D050198:Phenoxypropanolamines; D011412:Propanolamines; D013449:Sulfonamides; C071909:ICI D7114; C076126:disodium (R,R)-5-(2-((2-(3-chlorophenyl)-2-hydroxyethyl)-amino)propyl)-1,3-benzodioxole-2,3-dicarboxylate; D011433:Propranolol; D007545:Isoproterenol