Neuronal release of endogenous dopamine from corpus of guinea pig stomach.
Am J Physiol
; 273(5): G1044-50, 1997 11.
Article
em En
| MEDLINE
| ID: mdl-9374701
ABSTRACT
Neuronal release of endogenous dopamine was identified in mucosa-free preparations (muscle layer including intramural plexus) from guinea pig stomach corpus by measuring tissue dopamine content and dopamine release and by immunohistochemical methods using a dopamine antiserum. Dopamine content in mucosa-free preparations of guinea pig gastric corpus was one-tenth of norepinephrine content. Electrical transmural stimulation of mucosa-free preparations of gastric corpus increased the release of endogenous dopamine in a frequency-dependent (3-20 Hz) manner. The stimulated release of dopamine was prevented by either removal of external Ca2+ or treatment with tetrodotoxin. Dopamine-immunopositive nerve fibers surrounding choline acetyltransferase-immunopositive ganglion cells were seen in the myenteric plexus of whole mount preparations of gastric corpus even after bilateral transection of the splanchnic nerve proximal to the junction with the vagal nerve (section of nerves between the celiac ganglion and stomach). Domperidone and sulpiride potentiated the stimulated release of acetylcholine and reversed the dopamine-induced inhibition of acetylcholine release from mucosa-free preparations. These results indicate that dopamine is physiologically released from neurons and from possible dopaminergic nerve terminals and regulates cholinergic neuronal activity in the corpus of guinea pig stomach.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Estômago
/
Dopamina
/
Neurônios
Limite:
Animals
Idioma:
En
Revista:
Am J Physiol
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
Japão