Adenosine 2B receptors (A(2B)AR) on enteric neurons regulate murine distal colonic motility.
FASEB J
; 23(8): 2727-34, 2009 Aug.
Article
em En
| MEDLINE
| ID: mdl-19357134
ABSTRACT
Delayed colonic emptying leading to constipation is a significant health concern. We investigated the role of adenosine 2B receptor (A(2B)AR) in modulating distal colonic motility using wild-type and A(2B)AR-knockout (A(2B)AR(-/-)) mice. Colon motility was assessed using stool characteristics and colonic transit. Distal colonic ganglia, isolated by laser capture microdissection, were tested for A(2B)AR expression by RT-PCR. The distal colon contraction and relaxation responses were assessed by electrical field stimulation (EFS) in presence of A(2B)AR agonists, antagonists or inhibitors of nitric oxide (NO) and guanylate cyclase. Nitrite levels were measured in enteric neuronal cultures exposed to A(2B)AR agonists/antagonists. A(2B)AR(-/-) mice display increased stool retention, decreased stool frequency, delayed colonic emptying, and decreased circular muscle relaxation. RT-PCR identified A(2B)AR expression in distal colonic ganglia. EFS studies revealed that enteric neuronal A(2B)AR is essential for distal colonic relaxation, and A(2B)AR antagonists can inhibit relaxation. Enteric neurons stimulated with A(2B)AR agonists produced more nitrite than cultures treated with antagonists. We demonstrate an essential role of A(2B)AR in regulating distal colon relaxation, as A(2B)AR activation is linked to NO signaling. Hence targeting the colonic A(2B)AR could represent a novel therapeutic strategy to treat constipation.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Sistema Nervoso Entérico
/
Receptor A2B de Adenosina
/
Motilidade Gastrointestinal
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article