Alpha 2-mediated effect of dopamine on the motility of the chicken esophagus.
Dopamine (DA), apomorphine and B-HT 933 produced dose related contractions on isolated longitudinal strips of chicken esophagus, whereas phenylephrine elicited no effect. DA induced contractions of myogenic origin, these contractions were insensitive to DA antagonists and were partially suppressed by yohimbine, which suggested an alpha 2-adrenergic implication in this DA effect. This hypothesis was further investigated by performing binding experiments, in which B-HT 933 displaced the binding of [3H]DA to esophageal homogenates. The results suggest the participation of an alpha 2-adrenergic receptor in the contractile response elicited by DA in the isolated chicken esophagus.
Sánchez
J
J
Departamento de Fisiología Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Spain.
Costa
G
G
Benedito
S
S
Rivera
L
L
García-Sacristán
A
A
Orensanz
L M
LM
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D001381:Azepines / Q000494:pharmacology; D002645:Chickens; D004298:Dopamine / Q000494:pharmacology*; D004947:Esophagus / Q000187:drug effects* / Q000502:physiology; D005769:Gastrointestinal Motility / Q000187:drug effects; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D010656:Phenylephrine / Q000494:pharmacology
D000316:Adrenergic alpha-Agonists; D001381:Azepines; D010656:Phenylephrine; C015603:azepexole; D001058:Apomorphine; D004298:Dopamine