Toll-like receptors 2 and 4 modulate the contractile response induced by serotonin in mouse ileum: analysis of the serotonin receptors involved.
Neurogastroenterol Motil
; 27(9): 1258-66, 2015 Sep.
Article
em En
| MEDLINE
| ID: mdl-26053401
ABSTRACT
BACKGROUND:
Microbiota through toll-like receptors (TLR) may regulate gastrointestinal motility by activating neuroendocrine mechanisms. We evaluated the influence of TLR2 and TLR4 in the spontaneous contractions and serotonin (5-HT)-induced motor response in mouse ileum, and the 5-HT receptors involved.METHODS:
Muscle contractility studies to evaluate the spontaneous intestinal motility and the response to 5-HT were performed in the ileum from wild type (WT), TLR2(-/-), TLR4(-/-), and TLR2/4 double knockout (DKO) mice. 5-HT receptor expression was determined by real-time PCR. KEYRESULTS:
The amplitude of spontaneous contractions in ileum was higher in TLR2(-/-), TLR4(-/-), and TLR2/4 DKO mice with respect to WT. 5-HT evoked concentration-dependent contractile responses in the ileum from TLR2(-/-) and TLR4(-/-) mice similar to WT. However, in ileum from TLR2/4 DKO, 5-HT did not induce any contractile response. Expression of 5-HT2A, 5-HT2B, 5-HT2C, and 5-HT3 receptors resulted increased in ileum from TLR4(-/-) and TLR2/4 DKO. Expression of the 5-HT4 receptor was diminished in TLR2(-/-) and TLR2/4 DKO. High levels of 5-HT7 receptor expression were found in TLR2/4 DKO but not in TLR2(-/-) or TLR4(-/-). In WT and TLR4(-/-), 5-HT2, 5-HT3, 5-HT4, and 5-HT7 receptor antagonists reduced the contractile response evoked by 5-HT. In TLR2(-/-) mice, 5-HT4 antagonist did not reduce the 5-HT response. In TLR2/4 DKO mice, only 5-HT4 and 5-HT7 receptor antagonists reduced the relaxing response induced by 5-HT. CONCLUSIONS & INFERENCES TLR2 and TLR4 signaling may modulate the spontaneous contractions and the serotonin contractile response by acting on 5-HT2, 5-HT3, 5-HT4, and 5-HT7 receptors.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Serotonina
/
Receptores de Serotonina
/
Receptor 2 Toll-Like
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Receptor 4 Toll-Like
/
Motilidade Gastrointestinal
/
Íleo
Limite:
Animals
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article