Agonistic activity of SR59230A at atypical beta-adrenoceptors in guinea pig gastric fundus and duodenum.
We have recently suggested that atypical beta-adrenoceptors are present in guinea pig gastric fundus and duodenum. In the present study, we have shown that SR59230A (3-(2-ethylphenoxy)-1-[(1S)-1,2,3,4-tetrahydronaphth-1-ylamino]-(2S)-2-propanol oxalate), a selective beta(3)-adrenoceptor antagonist, possesses agonistic activities at atypical beta-adrenoceptors in these tissues. SR59230A caused concentration-dependent relaxations. However, (+/-)-propranolol (1 microM) did not affect SR59230A-induced relaxations. Pretreatment of with a combination of (+/-)-propranolol (1 microM) and the non-selective beta(1)-, beta(2)-, beta(3)- and beta(4)-adrenoceptor antagonist, (+/-)-bupranolol (30 microM), significantly antagonized the relaxant effects induced by SR59230A. The results clearly indicate that SR59230A acts as an atypical beta-adrenoceptor agonist on guinea pig gastric fundus and duodenum.
Department of Chemical Pharmacology, Toho University School of Pharmaceutical Sciences, 2-2-1, Miyama, Chiba 274-8510, Funabashi, Japan
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Horinouchi
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Koike
D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D002046:Bupranolol / Q000737:chemistry / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004386:Duodenum / Q000187:drug effects* / Q000502:physiology; D005748:Gastric Fundus / Q000187:drug effects* / Q000502:physiology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009126:Muscle Relaxation / Q000187:drug effects; D011412:Propanolamines / Q000494:pharmacology*; D011433:Propranolol / Q000737:chemistry / Q000494:pharmacology; D011943:Receptors, Adrenergic, beta / Q000187:drug effects* / Q000502:physiology; D013237:Stereoisomerism
C097869:3-(2-ethylphenoxy)-1-(1,2,3,4-tetrahydronaphth-1-ylamino)-2-propanol oxalate; D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D011412:Propanolamines; D011943:Receptors, Adrenergic, beta; D002046:Bupranolol; D011433:Propranolol