Involvement of beta1- and beta2- but not beta3-adrenoceptor activation in adrenergic PYY secretion from the isolated colon.
The secretion of PYY by endocrine L cells of the terminal gut is under the control of nutrients, the autonomic nervous system and hormones. Catecholamines, and the non-specific beta-adrenergic agonist isoproterenol induce PYY secretion from rat isolated colon or ileum. Because beta3-adrenergic receptors now appear to mediate many of the effects of catecholamines in the gastrointestinal tract, we investigated the involvement of beta1-, beta2-, and beta3-adrenoceptor stimulation in PYY secretion from the isolated, vascularly perfused rat colon. Infusion of 10(-6) M isoproterenol induced a transient increase in PYY secretion (from 36+/-4 to 87+/-20 fmol/2 min; n=7, P<0.05), that was abolished by a previous infusion of the beta1- and beta2-adrenergic blocker (and partial beta3-agonist) alprenolol (10(-6) M). The beta1-adrenergic agonist dobutamine and the beta-2 agonist terbutaline also (both at 10(-5) M) significantly stimulated PYY secretion, from 29+/-1 to 79+/-12 fmol/2 min and from 19+/-1 to 73+/-13 fmol/2 min respectively (n=7, P<0.05). Neither of the beta3-adrenergic agonists tested (BRL 37 344 (10(-5), 10(-6) M) and SR 58 611A (10(-6) M)) significantly stimulated PYY secretion, thus confirming the exclusive involvement of beta1- and beta2-receptors in beta-adrenergic agonist induced hormone secretion.
Brechet
S
S
U 45 INSERM, Hôpital Edouard Herriot, Pav H bis, 69437 Lyon Cédex 3, France.
Plaisancié
P
P
Dumoulin
V
V
Chayvialle
J A
JA
Cuber
J C
JC
Claustre
J
J
D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000526:Alprenolol / Q000494:pharmacology; D000818:Animals; D003106:Colon / Q000187:drug effects / Q000378:metabolism*; D004280:Dobutamine / Q000494:pharmacology; D004983:Ethanolamines / Q000494:pharmacology; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D023421:Models, Animal; D009924:Organ Culture Techniques; D019894:Peptide YY / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*; D018342:Receptors, Adrenergic, beta-1 / Q000378:metabolism; D018343:Receptors, Adrenergic, beta-2 / Q000378:metabolism; D022702:Receptors, Adrenergic, beta-3 / Q000378:metabolism; D018709:Statistics, Nonparametric; D013726:Terbutaline / Q000494:pharmacology; D013764:Tetrahydronaphthalenes / Q000494:pharmacology
D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D004983:Ethanolamines; D011943:Receptors, Adrenergic, beta; D018342:Receptors, Adrenergic, beta-1; D018343:Receptors, Adrenergic, beta-2; D022702:Receptors, Adrenergic, beta-3; D013764:Tetrahydronaphthalenes; D019894:Peptide YY; D004280:Dobutamine; C057368:BRL 37344; D000526:Alprenolol; D007545:Isoproterenol; D013726:Terbutaline; C076252:amibegron